Electrical supply system for a group of buildings

Abstract

An electrical supply system l for a group of buildings 3, wherein each building 3 in the group of buildings includes a consumer unit, the electrical supply system l including: an energy store 4 that i

Description

The present invention relates to an electrical supply system for a group of building, a method for providing electricity to a group of buildings, and a control system for an electrical supply system for a group of buildings. Background: Due to the impact of climate change, there is a strong desire to make housing more energy efficient and to be powered by low carbon sources of energy. To this end, highly polluting sources of energy such as coal and oil are being replaced by renewable sources of energy. It is also envisaged that the use of natural gas to heat homes will be phased out in the coming years, and natural gas will have to be replaced by an alternative energy source. It is likely that future heating systems will be powered by electricity, which will increase demand on the national grid. At the same time, there will be a significant increase in the number of electrically powered vehicles in use, which will further increase demand on the national grid. Thus, when building homes on a new residential site there is a need to ensure that the energy requirements of the homes can be adequately met, the scheme is energy efficient, in particular selecting appropriate heating systems to heat the homes and provide hot water to taps, and that provision is made for charging electric vehicles in a manner that minimizes the risk of overloading the local network. The residential site requires an electricity system that can meet these requirements. The electrical system should also be well balanced to meet energy requirements throughout the year. The same issues will also affect existing dwellings, accordingly there will be a need to retrofit existing dwellings to be more energy efficient and more sustainable, and sites that have a mixture of buildings, for example a mixture of residential, offices, commercial units, leisure units, generating plants, transport hubs, etc. There is also a need for local electrical systems to be more robust so that they can meet the electrical demands of the buildings they supply in unusual circumstances. For example, it is desirable for local electrical systems to be able to meet the electrical demands of the buildings they supply in the event that there is a loss of mains, wind power systems and / or solar power systems, caused by a bad weather event, such as low temperatures, excessive windspeeds, or heavy precipitation. Accordingly the invention seeks to provide an electrical system for a group of buildings, a method for providing electricity to a group of buildings and a control system for an electrical supply system for a group of buildings that mitigates at least one of the above-mentioned problems, or to at least to provide alternative systems and methods to known systems and methods. Summary of Invention: According to one aspect there is provided an electrical system according to claim 1. The weather alert notifies the control system of weather events that may affect the normal operation of the electrical supply system during the bad weather event, thereby enabling the control system to prepare the local electrical supply system for the bad weather event. Bad weather means a type of weather condition that exceeds a high threshold value for at least one weather parameter or that exceeds a low threshold value for at least one weather parameter. Weather parameters can include, for example temperature, wind speed, rain and snow. According to another aspect of the invention there is provided an electrical supply system for a group of buildings, wherein each building in the group of buildings includes a consumer unit. The electrical supply system can include an energy store that is arranged to supply electricity to the consumer unit for each building in the group of buildings, in at least one operational condition. The electrical supply system can include at least one electrical supply source that is arranged to charge the energy store, in at least one operational condition. The electrical supply system can include a control system. The control system can be arranged to monitor the state of charge of the energy store. The control system can be arranged to receive weather alerts. In response to receiving a weather alert that indicates that bad weather is likely to occur within the vicinity of the group of buildings within a forecast period, the control system can be arranged to control operation of the at least one electrical supply source to increase the state of charge of the energy store prior to the bad weather arriving at the group of buildings. The control system can be arranged to supply electricity from the energy store to the building consumer units during the bad weather event, for example in a condition wherein electrical demand from the building consumer units exceeds an available supply. The at least one electrical supply source can include a solar power system for converting solar energy into electrical energy. The solar power system can be electrically connected to the energy store. The solar power system can be arranged to supply electricity to the energy store, in at least one operational condition. The at least one electrical supply source can include a wind power system for converting wind energy into electrical energy. The wind power system can be electrically connected to the energy store. The wind power system can be arranged to supply electricity to the energy store, in at least one operational condition. The at least one electrical supply source can include an auxiliary power supply. The auxiliary power supply can be electrically connected to the energy store. The auxiliary power supply can be arranged to supply electricity to the energy store, in at least one operational condition. The at least one electrical supply source can include a mains power supply. The mains power supply can be electrically connected to the energy store. The mains power supply can be arranged to supply electricity to the energy store, in at least one operational condition. According to one aspect there is provided an electrical system according to claim 2. The weather alert notifies the control system of weather events that may affect the normal operation of the electrical supply system during the bad weather event, thereby enabling the control system to prepare the local electrical supply system for the bad weather event. Bad weather means a type of weather condition that exceeds a high threshold value for at least one weather parameter or that exceeds a low threshold value for at least one weather parameter. Weather parameters can include, for example temperature, wind speed, rain and snow. According to another aspect there is provided an electrical supply system for a group of buildings, wherein each building in the group of buildings includes a consumer unit. The electrical supply system can include an energy store that is arranged to supply electricity to the consumer unit for each building in the group of buildings, in at least one operational condition. The energy store can be electrically connected to each consumer unit. The electrical supply system can include a solar power system for converting solar energy into electrical energy, wherein the solar power system is arranged to supply electricity to the energy store, in at least one operational condition. The solar power system can be electrically connected to the energy store. The electrical supply system can include a wind power system for converting wind energy into electrical energy, wherein the wind power system is arranged to supply electricity to the energy store, in at least one operational condition. The wind power system can be electrically connected to the energy store. The electrical supply system can include an auxiliary power supply. The auxiliary power supply can be electrically connected to the energy store. The auxiliary power supply can be arranged to supply electricity to the energy store, in at least one operational condition. The electrical supply system can include a mains power supply. The mains power supply can be electrically connected to the energy store. The mains power supply can be arranged to supply electricity to the energy store, in at least one operational condition. The electrical supply system can include a control system. The control system can be arranged to monitor the state of charge of the energy store. The control system can be arranged to receive alerts relating to bad weather in the vicinity of the group of buildings. In response to receiving a bad weather alert, the control system can be arranged to control operation of at least one of the solar power system, wind power system, auxiliary power supply and mains power supply to increase the state of charge of the energy store prior to the bad weather arriving at the group of buildings. The control system can prepare, as best as it is able to do so in the circumstances, the local electrical supply system to meet the electrical demand for the group of buildings for the duration of the bad weather event. In some embodiments, the control system can be arranged to charge the energy store to a maximum state of charge prior to the bad weather arriving or to the maximum state of charge that can be achieved prior to the bad weather arriving. The bad weather alert can relate to any type of weather condition that may impact the normal functioning of the electrical supply system to the group of buildings, for example due to an increased risk of equipment failure in the electrical supply system, or equipment failure in the wider mains grid. The control system can be arranged to receive the weather alert via any suitable electronic means. For example, the weather alert can be provided by email, short-message-service message (text message), via an Application Programming Interface (API), which provides access to weather data and alerts database via a network connection, a radio signal issued by a weather alert service, which can be received at a receiver connected to the control system. The control system can also include a Human Machine Interface (HMI) to enable a user to provide a weather alert to the control system manually. The control system can be arranged to supply electricity from the energy store to the consumer units during the bad weather event. The control system can be arranged to supply electricity from the energy store to the consumer units during other operational conditions. For example the control system can be arranged to supply electricity from the energy store to the consumer units during low speed wind conditions wherein the output from the wind power system can be low. The control system can be arranged to supply electricity from the energy store to the consumer units during low light conditions wherein the output from the solar power system can be low. The control system can be arranged to supply electricity from the energy store to the consumer units during a loss of mains power supply to the consumer units. The control system can comprise at least one programmable logic controller, which can be connected to the devices it controls via a network connection. At least part of the control system can be programmed into a general purpose computer. The group of buildings can include at least one of: housing, commercial units, office space, city farms, data centres, industrial units, leisure facilities, entertainment venues, etc, all of which can be located within a defined site boundary, which is served the electrical supply system. The weather alert can include an estimated time of arrival of the bad weather at the group of buildings. The estimated time of arrival can be provided as a number of hours / days until the bad weather arrives at the group of buildings and / or a date and time, from which it is possible to calculate the number of hours / days until the bad weather arrives. In some embodiments, the weather alert provides an estimated duration of the bad weather event. The control system can be arranged to determine a charging period, wherein the charging period is the period of time available to charge the energy store before the bad weather arrives at the group of buildings. The control system can be arranged to determine the charging period from the estimated time of arrival of the bad weather, at the group of buildings, in the weather alert. For example, the control system can calculate the charging period using the estimated time of arrival of the bad weather and an output form a clock that indicates the current time and date. The control system can be arranged to charge the energy store to a maximum state of charge prior to the bad weather arriving at the group of buildings, or to at least charge the energy store to the greatest charge achievable charge prior to the bad weather arriving at the group of buildings. The control system can be arranged to determine a charging strategy for charging the energy store prior to the bad weather arriving at the group of buildings. For example, the control system can be arranged to determine a charging strategy for charging the energy store to a maximum state of charge for the energy store within the charging period, or a charging strategy to charge the energy store to the greatest charge that can be achieved within the charging period. The control system can be arranged to prioritise charging of the energy store with at least one of the solar power system and the wind power system prior to the bad weather arriving at the group of buildings. This helps to ensure a maximum use of renewable energy to charge the energy store. The weather alert can include weather forecast data. For example, the weather forecast data can include data regarding available sunlight over the forecast period in the vicinity of the solar power system. The control system can be arranged to estimate the total electrical energy output from the solar power system prior to the bad weather arriving at the group of buildings, and to formulate the charging strategy, at least in part, based on the estimated electrical energy output from solar power system. For example, in some scenarios, the solar power system may generate sufficient electrical energy to fully charge the energy store prior to the bad weather arriving. In other scenarios, the solar power system may generate a proportion of the electrical energy required to fully charge the energy store prior to the bad weather arriving. For example, in some scenarios the solar power system may generate around 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or less than 10%, of the energy required to fully charge the energy store prior to the bad weather arriving. The weather forecast data can include data regarding wind speed over the forecast period in the vicinity of the wind power system. The control system can be arranged to estimate the total electrical energy output from the wind power system prior to the bad weather arriving at the group of buildings, and to formulate the charging strategy, at least in part, based on the estimated electrical energy output from wind power system. For example, in some scenarios, the wind power system may generate sufficient electrical energy to fully charge the energy store prior to the bad weather arriving. In other scenarios, the wind power system may generate a proportion of the electrical energy required to fully charge the energy store prior to the bad weather arriving. For example, in some scenarios the wind power system may generate around 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or less than 10%, of the energy required to charge the energy store prior to the bad weather arriving. Typically, the wind power system can be located adjacent to the group of buildings. The charging strategy can include supplying electricity to the energy store from the auxiliary supply, for example to make up at least a proportion of any shortfall in electrical supply from the solar power system and / or the wind power system prior to the bad weather arriving at the group of buildings. For example, in some scenarios the auxiliary power system may generate around 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or less than 10%, of the energy required to charge the energy store prior to the bad weather arriving. The charging strategy can include supplying electricity to the energy store from the mains power supply, for example to make up at least a proportion of any shortfall in electrical supply from the solar power system and / or the wind power system during the charging in period. For example, in some scenarios the mains power system may generate around 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or less than 10%, of the energy required to charge the energy store prior to the bad weather arriving. The control system can be arranged to select between the auxiliary power supply and the mains power supply during the period prior to the bad weather arriving according to at least one parameter. The at least one parameter can include the control system determining the availability of the auxiliary power supply and / or the mains power supply during the charging period, or the remaining portion of the charging period. For example, an absence of an electrical signal from the auxiliary power supply to the control system can indicate a lack of availability of the auxiliary power supply, for example due to a lack of fuel, or difficulties in activating the auxiliary power supply from a dormant state. For example, an absence of an electrical signal from the mains power supply to the control system can indicate a lack of availability of the mains supply, for example due to a fault in the mains power supply system. The at least one parameter can include the control system being arranged to select between the auxiliary power supply and the mains power supply according to an estimated cost of supply value for each of the mains power supply and the auxiliary power supply. For example, the control system can be arranged to give priority to the power supply that can provide the required electrical energy to the energy store at the lowest cost. The electrical supply system of any one of the preceding claims, wherein the auxiliary power supply can comprise a generator, and preferably a biodiesel generator. The energy store can comprise at least one electrochemical cell. An arrangement of electrochemical cells is commonly referred to as a battery. For example, the battery can be arranged to supply electricity to the consumer units of the buildings in at least some conditions in order to power electrical loads connected to the consumer units. Thus the battery can be a communal battery since it can be arranged to supply electricity to a plurality of buildings, and possibly every building on the site. In some embodiments the battery can be rated at 500kWh - 3MWh. The control system can be arranged to continue to charge the energy store after the arrival of the bad weather at the group of buildings, in at least one operational condition. The control system can be arranged to discharge at least some electrical energy from the energy store to the consumer units at peak demand times and / or loss of supply from at least one of the solar power system, wind power system and mains power supply, in at least one operational condition. The control system can be arranged to monitor demand form the buildings, if demand rises at non-peak times, the control system can be arranged to supply energy from the energy store to the consumer units to meet increased demand. The control system can be arranged to determine from the weather alert that the temperature in the vicinity of the group of buildings is forecast to drop below a low temperature threshold value or to exceed a high temperature threshold value. The low temperature threshold value can be, for example 4°C, 3°C, 2°C, 1°C, 0°C, -1°C, -2°C, -3°C, or -4°C. Other suitable values for the low temperature threshold value can be selected according to electrical system set up, and typical temperatures experienced in the vicinity of the group of buildings. For example, in cold countries, and electrical systems that can be set up for the cold, the low temperature threshold value can be, for example -20°C, -21°C, -22°C, -23°C, -24°C, -25°C. In response to receiving a weather alert, which indicates that the temperature in the vicinity of the group of buildings can be forecast to drop below a low temperature threshold value, the control system can be arranged to charge the energy store, preferably to a maximum value prior to the low temperatures occurring. In response to receiving a weather alert, which indicates that the temperature in the vicinity of the group of buildings can be forecast to drop below a low temperature threshold value, the control system can be arranged to activate a heating system to heat at least one heat storage tank prior to the low temperatures occurring. This helps to reduce the electrical load during the bad weather event. The control system can be arranged to determine from the weather alert that the temperature in the vicinity of the group of buildings is forecast to rise above a high temperature threshold value. The high temperature threshold value can be, for example 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C or 40°C. Other suitable values for the high temperature threshold value can be selected according to electrical system set up, and typical temperatures experienced. For example, in hot countries the high temperature threshold value can be, for example 45°C, 46°C, 47°C, 48°C, 49°C or 50°C. In response to receiving a weather alert, which indicates that the temperature in the vicinity of the group of buildings can be forecast to exceed a high temperature threshold value, the control system can be arranged to charge the energy store, preferably to a maximum value prior to the high temperatures occurring. In response to receiving a weather alert, which indicates that the temperature in the vicinity of the group of buildings can be forecast to exceed a high temperature threshold value, the control system can be arranged to activate a cooling system to cool a cold storage tank prior to the bad weather occurring. This helps to reduce the electrical load during the bad weather event. The weather alert can include the amount of rainfall forecast for the group of buildings during the forecast period. The control system can be arranged to determine from the weather alert, if the rainfall in the vicinity of the group of buildings is forecast to be greater than a rainfall threshold value. The weather alert can include the amount of snow forecast for the group of buildings. The control system can be arranged to determine from the weather alert if snowfall in the vicinity of the group of buildings is forecast to be greater than a snowfall threshold value. The weather alert can include the windspeeds forecast for the group of buildings. The control system can be arranged to determine from the weather alert if windspeed in the vicinity of the group of buildings is forecast to be greater than a windspeed threshold value. The electrical supply system can include a long-term energy store. The control system can be arranged to control actuation of the long-term energy store to selectively supply electricity to at least one of: the consumer units and the energy store. The control system can be arranged to actuate the long-term energy store to make up a shortfall in electrical energy supply to the consumer units, for example during a bad weather event. The control system can be arranged to actuate the long-term energy store in response to receiving the weather alert. The control system can be arranged to actuate the long-term energy store in response to determining a shortfall in electricity supply to the consumer units. The shortfall may occur, for example due to a loss of mains power supply and / or a loss of power supply from the energy store and / or a loss of power supply from the wind power supply and / or a loss of power from the solar power supply and / or a loss of power from the auxiliary power supply. The long-term energy store can comprise a fuel cell. The control system can be arranged to actuate the fuel cell. The long-term energy store can comprise a hydrogen store. For example, a hydrogen storage vessel. The long-term energy store can comprise an electrolyser. The electrolyser can be arranged to produce hydrogen. The control system can be arranged to control operation of the electrolyser to produce hydrogen. The electrolyser can be powered by at least one renewable energy source, for example at least one of the solar power system and the wind power system. The control system can be arranged to selectively supply electrical power to the electrolyser from at least one of the wind power system and the solar power system to produce hydrogen. Any hydrogen produced by the electrolyser can be stored in the hydrogen store. When electricity is required from the long-term energy store, hydrogen can be supplied from the hydrogen store to the fuel cell. The fuel cell uses the hydrogen to generate electricity and the electricity produced by the fuel cell can be supplied to the consumer units. The electrical supply system can include at least one electrical vehicle having a rechargeable battery, and a two way electrical charger, wherein the two way electrical, wherein the control system, in response to receiving the weather alert, is arranged to charge the electric vehicle rechargeable battery to a maximum state of charge prior to the bad weather arriving, or to the maximum state of charge that can be achieved prior to the bad weather arriving. The control system can be arranged to supply electricity from the at least one electric vehicle battery to the consumer units during the bad weather event. The electrical supply system can include a plurality of electrical vehicles and a plurality of two way electrical chargers. The control system, in response to receiving the weather alert, can be arranged to charge each electric vehicle rechargeable battery to a maximum state of charge prior to the bad weather arriving, or to the maximum state of charge that can be achieved prior to the bad weather arriving, and to supply electricity from each electric vehicle rechargeable battery to the consumer units during the bad weather event. At least one, and preferably a plurality, of the electric vehicles can be autonomous vehicles. It can be envisaged that at least some sites will have a fleet of electric vehicles providing public transport around the site. In response to the control system receiving the weather alert, the control system can be arranged to recall at least one, and preferably a plurality, of the autonomous vehicles back to their respective charging locations, or prevent the autonomous vehicles from leaving their charging stations. The control system can be arranged to charge the batteries of the autonomous vehicles during the charging period and to at least partially discharge the autonomous vehicle batteries during the bad weather event to supply electricity to the consumer units. The solar power system can include an arrangement of photovoltaic modules (commonly referred to as solar panels). At least some photovoltaic modules can be mounted on buildings. At least some photovoltaic modules can be located on a solar farm located on, or adjacent to, the site having the group of buildings. The solar power system can be dedicated to the site. The photovoltaic modules can be electrically connected to the energy store. The photovoltaic modules can be electrically connected to the consumer units via the local electrical network. For residential sites having a plurality of buildings, at least some of the buildings, and preferably each building, can include at least one photovoltaic module. The solar power system can include a floating solar power system. For example, an arrangement of photovoltaic modules can be mounted on a float, which enables the photovoltaic modules to be deployed on water. The wind power system can include an arrangement of wind turbines. At least some of the wind turbines can be located in a designated wind farm located on, or adjacent to, the site having the group of buildings. Some wind turbines can be mounted on or adjacent to the buildings. The wind power system can be dedicated to the local site. The wind turbines can be electrically connected to the local electrical network on the site by means of a public or private connection. The wind power system can be electrically connected to the consumer units via the local electrical network. The electrical supply system can include at least one direct current (DC) / alternating current (AC) invertor. In some embodiments the solar power system can be electrically connected to the consumer units, and can be arranged to supply electricity to the consumer units. In some embodiments a DC / AC invertor can be provided to convert a DC generated by the solar power system to an AC for the consumer units. In some embodiments the wind power system can be electrically connected to the consumer units, and can be arranged to supply electricity to the consumer units. In some embodiments a DC / AC invertor can be provided to convert a DC generated by the wind power system to an AC for the consumer units. In some embodiments a DC / AC invertor can be provided to convert a DC supplied by the energy store to an AC for the consumer units. In some embodiments the fuel cell can be electrically connected to the consumer units. In some embodiments a DC / AC invertor can be provided to convert a DC generated by the fuel cell to an AC for the consumer units. In some embodiments the electric vehicle batteries can be electrically connected to the consumer units. In some embodiments a DC / AC invertor can be provided to convert a DC supplied by the electric vehicle batteries to an AC for the consumer units. A DC output from the solar power supply can be provided to the energy store. A DC output from the wind power supply can be provided to the energy store. A DC output from the auxiliary power supply can be provided to the energy store. An AC mains supply can be converted by an AC / DC converter for supplying the energy store with a DC. The wind power system can be electrically connected to the electrolyser. DC from the wind power system can be supplied to the electrolyser. The solar power system can be electrically connected to the electrolyser. DC from the solar power system can be supplied to the electrolyser. In some embodiments the control system can be arranged to export electricity from the energy store to the grid. In some embodiments the control system can be arranged to export electricity from the wind power system to the grid. In some embodiments the control system can be arranged to export electricity from the solar power system to the grid. In some embodiments the control system is arranged to estimate the total amount of electrical demand from the group of buildings during the bad weather event. This can be achieved by the control system estimating the electrical demand from the buildings for normal operation of the buildings for the bad weather period for the bad weather event. The control system can use historical electrical load data for each building, and the knowledge of the duration and time of the bad weather event, to estimate the electrical energy required for each building during normal operation for the equivalent period for the bad weather event. For example, if the bad weather event is to take place from Friday to Monday in early November, the control system analyses the historical electrical demand for each building during that time period, and determines an estimated electrical demand for each building. The estimated electrical demand for each building can be summed to obtain an estimate for the site electrical demand. The control system can be arranged to adjust the electrical demand estimate for each building during the bad weather period to allow for the effect that the bad weather is likely to have on the electrical demand. For example, the estimate for each building can be adjusted by a suitable factor, e.g. by 1.1 for a 10% increase in demand, by adding an expected amount of electrical demand, or by subtracting an expected amount of electrical demand. This can be done for each individual building, and the adjusted figures can be summed to obtain an adjusted estimate for the site electrical demand. In some embodiments, the adjustment can be made to the estimate for site electrical demand estimate only, to reduce the calculation burden. The control system can include a machine learning system that is arranged to adjust the electrical demand estimate. Over time, the machine learning system will be able to better determine the likely effect that a particular bad weather event will have on normal electrical demand for each building. For example, electric meter readings can be recorded so that changes in electrical demand can be determined during bad weather events. The machine learning system is able to determine from the data the manner in which electric demand changes for each building for particular types of bad weather event. Thus, over time, more accurate adjustments to expected electrical demand can be made for each building. Based on the weather data, the control system can be arranged to estimate the electrical output from the solar power system over the period for the bad weather event. Based on the weather data, the control system can be arranged to estimate the electrical output from the wind power system over the period for the bad weather event. In the event that the estimated energy to be supplied by the solar power system and / or wind power system to the consumer units is insufficient to meet the needs of all of the buildings for the duration of the bad weather event, the control system can be arranged to supplement the electrical energy supplied to the consumer units by supplying the consumer units with electricity from the energy store. In the event that the energy supplied by the solar power system, wind power system and energy store to the consumer units is insufficient to meet the needs of all of the buildings for the duration of the bad weather event, the control system can be arranged to supplement the electrical energy supplied to the consumer units by supplying the consumer units with electricity from at least one of: the long-term energy store, the electric vehicle batteries, the AC generator and the mains power supply. In some embodiments the consumer unit for each building has a first part and a second part, wherein essential loads can be connected to the first part of the consumer unit and non-essential loads can be connected to the second part of the consumer unit. An essential load can include at least one of the following: electrical heating system, cooker, fridge freezer and lighting, telephone lines, etc. Non-essential loads can include at least one of the following: ring mains for televisions, musical equipment, cleaning equipment, etc. During a bad weather event, the control system can be arranged to supply electricity to the first part of the consumer unit, and not supply the second part of the consumer unit. According to another aspect there can be provided a method according to claim 41. According to another aspect there is provided a method of supplying electricity to a group of buildings, wherein each building in the group of buildings includes a consumer unit. The electrical system can be arranged according to any configuration described herein. The method can include providing an electrical supply system for the group of buildings, having: an energy store that can be arranged to supply electricity to the consumer unit for each building in the group of buildings, in at least one operational condition; a solar power system for converting solar energy into electrical energy, wherein the solar power system can be arranged to supply electricity to the energy store, in at least one operational condition; a wind power system for converting wind energy into electrical energy, wherein the wind power system can be arranged to supply electricity to the energy store, in at least one operational condition; an auxiliary power supply and / or a mains power supply, wherein at least one of the auxiliary power supply and the mains power supply can be arranged to supply electricity to the energy store, in at least one operational condition; and a control system. The method can include the control system monitoring the state of charge of the energy store. The method can include the control system receiving a weather alert relating to bad weather in the vicinity of the group of buildings within a forecast period. The method can include the control system, in response to receiving a weather alert, controlling operation of at least one of the solar power system, wind power system, auxiliary power supply and mains power supply to increase the state of charge of the energy store prior to the bad weather arriving at the group of buildings. According to another aspect there can be provided a control system according to claim 42. A control system for an electrical supply system for a group of buildings, wherein each building in the group of buildings includes a consumer unit, and the electrical supply system can include: an energy store that can be arranged to supply electricity to the consumer unit for each building in the group of buildings, in at least one operational condition; a solar power system for converting solar energy into electrical energy, wherein the solar power system can be arranged to supply electricity to the energy store, in at least one operational condition; a wind power system for converting wind energy into electrical energy, wherein the wind power system can be arranged to supply electricity to the energy store, in at least one operational condition; an auxiliary power supply and / or a mains power supply, wherein at least one of the auxiliary power supply and the mains power supply can be arranged to supply electricity to the energy store, in at least one operational condition. The control system can be arranged to any configuration described herein. The control system can be arranged to monitor the state of charge of the energy store. The control system can be arranged to receive weather alerts. In response to receiving a weather alert that indicates that bad weather is likely to occur within the vicinity of the group of buildings within a forecast period weather alert, the control system can be arranged to control operation of the solar power system to increase the state of charge of the energy store prior to the bad weather arriving at the group of buildings. In response to receiving a weather alert that indicates that bad weather is likely to occur within the vicinity of the group of buildings within a forecast period weather alert, the control system can be arranged to control operation of the wind power system to increase the state of charge of the energy store prior to the bad weather arriving at the group of buildings. In response to receiving a weather alert that indicates that bad weather is likely to occur within the vicinity of the group of buildings within a forecast period weather alert, the control system can be arranged to control operation of the auxiliary power supply to increase the state of charge of the energy store prior to the bad weather arriving at the group of buildings. In response to receiving a weather alert that indicates that bad weather is likely to occur within the vicinity of the group of buildings within a forecast period weather alert, the control system can be arranged to control operation of the mains power supply to increase the state of charge of the energy store prior to the bad weather arriving at the group of buildings. According to another aspect there is provided an electrical supply system for a group of buildings, the electrical supply system including: at least one thermal energy store that is arranged to supply heat to each building in the group of buildings, in at least one operational condition; at least one heating device, such as a heat pump, that is arranged to supply heat to the at least one thermal energy store, in at least one operational condition; at least one electrical supply source that is arranged to supply electricity to the at least one heating device, in at least one operational condition; and a control system arranged to monitor the state of charge of the at least one thermal energy store and to receive weather alerts, wherein, in response to receiving a weather alert that indicates that bad weather is likely to occur within the vicinity of the group of buildings within a forecast period, the control system is arranged to control operation of the at least one electrical supply source to power the heating device to increase the thermal energy stored in the at least one thermal energy store prior to the bad weather arriving at the group of buildings. The electrical supply system can be arranged according to any aspect described herein. According to another aspect of the invention there is provided an electrical supply system for a group of buildings, including: at least one thermal energy store that is arranged to supply heat to each building in the group of buildings, in at least one operational condition; at least one heating device, such as a heat pump, that is arranged to supply heat to the at least one thermal energy store, in at least one operational condition; a solar power system for converting solar energy into electrical energy, wherein the solar power system is arranged to supply electricity to the at least one heating device, in at least one operational condition; a wind power system for converting wind energy into electrical energy, wherein the wind power system is arranged to supply electricity to the at least one heating device, in at least one operational condition; and a control system arranged to monitor the state of charge of the at least one thermal energy store and to receive alerts relating to bad weather in the vicinity of the group of buildings, wherein, in response to receiving a bad weather alert, the control system is arranged to control operation of at least one of the solar power system and the wind power system to supply electricity to the at least one heating device to increase the thermal energy stored in the at least one thermal energy store prior to the bad weather arriving at the group of buildings. The electrical supply system can be arranged according to any aspect described herein. The electrical supply system can include an auxiliary power supply. The auxiliary power supply can be electrically connected to the heating device. The auxiliary power supply can be arranged to supply electricity to the heating device, in at least one operational condition. The electrical supply system can include a mains power supply. The mains power supply can be electrically connected to the heating device. The mains power supply can be arranged to supply electricity to the heating device, in at least one operational condition. Brief Description of Drawings Embodiments will now be described, by way of example only and with reference to accompanying drawings, in which: Figure 1 is a schematic of an electrical system for a group of buildings according to a first embodiment of the invention; Figure 2 is a schematic of showing how control system communications with equipment in the electrical system of Figure 1; Figure 3 is a schematic showing electricity meters for the group of buildings and electrical system equipment; Figures 4a and 4b are parts of a flow diagram showing a first mode of operation for the electrical system, no bad weather alert is received by the control system; Figures 5a and 5b are parts of a flow diagram showing a second mode of operation for the electrical system, no bad weather alert is received by the control system; Figure 6a and 6b are parts of a flow diagram showing a third mode of operation for the electrical system, no bad weather alert is received by the control system; Figures 7a to 7c are parts of a flow diagram showing a fourth mode of operation for the electrical system, where a bad weather alert is received by the control system; Figure 8a and 8b are parts of a flow diagram showing a fifth mode of operation for the electrical system, no bad weather alert is received by the control system; Figures 9a and 9b are parts of a flow diagram showing a sixth mode of operation for the electrical system, where a bad weather alert is received by the control system; and Figure 10a and 10b are parts of a flow diagram showing a seventh mode of operation for the electrical system, no bad weather alert is received by the control system. Detailed Description: Figure 1 shows an electrical system 1 for a group of buildings 3 in accordance with the invention. The group of buildings 3 can be or any suitable type, and may include, for example, at least one of: a plurality of residential units 5; a transport hub 33, a vertical farm 9, commercial units, sports facilities, factories 11, data centres 13, offices, leisure centres, schools, and entertainment venues. The group of buildings 3 are located in close proximity to one another, for example the group of buildings may all be located on a development site, which is part of a town, village or city. The site can include any practicable number of buildings 3, and typically includes multiple residential units 5, such as tens of residential units 5, hundreds of residential units 5 or thousands of residential units 5. Typically, the site can include around 1 to 200 residential units 5, however the site can include any practicable number of residential units 5, and therefore may have more than 200 residential units 5. Each building 3 has a consumer unit (not shown), which is arranged to receive electricity from the electrical system 1, and to distribute the electricity received to various electrical loads within the building 5. In some embodiments, the consumer unit has a first part for essential electrical loads, that is electrical loads for which it is highly undesirable to interrupt the supply of electricity to those loads, for example during a bad weather event, and a second part for non-essential electrical loads, for which it is ok to interrupt the supply of electricity to those loads, for example during a bad weather event. An essential load can include at least one of the following: electrical heating system, cooker, fridge freezer and lighting, telephone lines, etc. Non-essential loads can include at least one of the following: ring mains for televisions, musical equipment, cleaning equipment, etc. The electrical system 1 includes a local electrical network 15 (hereinafter “local network 15”). Each building consumer unit is part of the electrical system 1 and is electrically connected to the local electrical network 15. In some embodiments, the local network 15 is electrically connected to the mains electrical supply 17, and thus mains electricity can be supplied to the building consumer units. In some embodiments no mains electrical supply is available, and thus the site is essentially islanded and self-sufficient. The electrical system 1 includes at least one energy store 4, for example in the form of at least one electrochemical cell, commonly referred to as a battery. Typically, the battery has a large capacity, for example it can be rated at 500kWh - 3MWh. The battery 4 is electrically connected to the local network 15 via a direct current (DC) to alternating current (AC) converter, and can be arranged to supply electricity to the consumer units of the buildings in at least one operational condition in order to power electrical loads connected to the consumer units. Thus the battery 4 is a communal battery since the battery 4 is arranged to supply electricity to a plurality of buildings 3, and possibly every building 3 in the group of buildings on the site, in at least one operational condition. The electrical system 1 includes a wind power system 19, which can be located at windfarm located adjacent to at least some of the buildings 3. The wind power system 19 includes apparatus arranged to generate electricity from the wind. The apparatus can comprise any suitable wind turbines required to meet at least part of the electrical requirements of the buildings 3 when operational. The wind power system 19 is electrically connected to the local network 15 via an electrical connection and an inverter (not shown), which converts a DC from the wind turbines to an AC for the local network 15. Thus, in at least one operational condition, the wind power system 19 is arranged to supply electricity to the building consumer units via the local network 15. The wind power system 19 is electrically connected to the battery 4, and is arranged to supply a DC to the battery 4. In at least one operational condition, the wind power system 19 is arranged to charge the battery 4 by supplying electricity to the battery 4. The electrical system 1 includes a solar power system 21, which can be located at a solar farm located adjacent to at least some of the buildings 3. The solar power system 21 includes apparatus arranged to generate electricity from sunlight, for the example the solar power system 21 can include photovoltaic modules. The apparatus is electrically connected to the local network 15 via an electrical connection 21 and an inverter (not shown), which converts a DC from the photovoltaic modules to an AC for the local network 15. Thus, in at least one operational condition, the wind power system 19 is arranged to supply electricity to the building consumer units via the local network 15. In some embodiments, the solar power system 21 can include floating photovoltaic modules, which are located on a body of water such as a lake, reservoir or pond, in addition or as an alternative to land mounted photovoltaic modules. The solar power system 21 is electrically connected to the battery 4, and is arranged to supply a DC to the battery 4. In at least one operational condition, the solar power system 21 is arranged to charge the battery 4 by supplying electricity to the battery 4. The electrical system 1 can include at least one auxiliary power supply 23 that is arranged to charge the battery 4. For example, the electrical system 1 can include at least one biodiesel generator, that is arranged charge the battery 4, when activated. The biodiesel generator can be switched on / off according to the charging requirements for the battery 4. For example, if it is desired to charge the battery 4 to its full capacity within a predetermined period of time, and this cannot be achieved by charging the battery 4 with the wind power system 19 and solar power system 21, the auxiliary power supply 23 can be activated to help ensure that the battery is fully charged with the predetermined period of time. The electrical system 1 can include a long-term energy storage system 25, which can be actuated to supply electricity to the local network 15, and hence the building consumer units, in some circumstances. For example, the long-term energy storage system 25 can include a hydrogen storage tank 27 and a fuel cell 29. Hydrogen can be stored in the hydrogen storage tank 27, and can be provided to the fuel cell 29 to generate electricity, for example at a time when there is a short fall in electrical supply to meet the demand. The long-term energy storage system 25 can include a means for producing hydrogen locally. For example, the long-term energy storage system 25 can include an electrolyser 31, which can be used to generate hydrogen. The electrolyser 31 can be powered by electricity from a renewable source of energy, such as the wind power system 19, which helps to ensure that the electrolyser 31 produces hydrogen efficiently, and a non-polluting manner. The hydrogen produced by the electrolyser 31 can be stored in the hydrogen storage tank 27. In some embodiments the electrical system 1 can include an AC generator 24 that is arranged to supply an AC to the local network 15. The site can include a transport hub 33, which can include a number of autonomous vehicles 35, such as autonomous cars, minibuses and buses, for providing transport around the site. At least some of the autonomous vehicles 35 are electric vehicles, and the transport hub 33 includes a plurality of bidirectional chargers 37 (sometimes referred to as two way charging units) which are electrically connected to the local network 15. The bidirectional chargers 37 enable autonomous vehicle batteries to be charged by electricity received from the local network 15, for example from the wind power system 19, solar power system 21, battery 4 and / or mains supply 17. The bidirectional chargers 37 also enable the autonomous vehicle batteries to supply electricity to the local network 15, in at least one operational condition, and therefore the autonomous vehicle batteries are able to supply electricity to the building consumer units when required. It is envisaged that, in a condition wherein it is necessary to supply electricity to the local network 15 from the autonomous vehicle batteries in the near future, that autonomous vehicles already connected to the bidirectional chargers 37 would be prevented from leaving the transportation hub 33. It is also envisaged that, a “return to base” signal may be sent to at least one autonomous vehicle that is located away from the transport hub 33, in order to return one or more autonomous vehicles to the transport hub 33, have the autonomous vehicle connected to one of the bidirectional chargers 37 to either supply electricity to the local network 15, or to charge the autonomous vehicle battery such that it is in a condition to supply electricity to the local network 15 in the near future. At least some of the buildings 3 can include energy sources, such as solar power systems 39 and batteries 41, which are connected to their respective consumer units via an inverter. In some embodiments, the building energy sources can be connected to the local network 15, to enable electricity generated or stored to be supplied to other buildings in at least one operational condition. At least some buildings 3 can include at least one bidirectional vehicle charger 43, which enables private electrical vehicles 45 to be charged. The bidirectional vehicle chargers 43 can be connected to the local network 15 to enable the private electrical vehicles 45 to supply electricity to the building consumer units, under at least one operational condition. Figure 3 shows a possible configuration of site electricity meters. The electrical system 1 can include a site electricity meter 47. The site electricity meter 47 can be a two-way meter 49b, which is arranged to monitor the amount of electricity supplied to the local network 15 from the mains supply 17 and to monitor the amount of electricity supplied from the local network 15 to the mains supply 17. Each building 3 has an electricity meter. Some buildings 3 have a one-way type of meter 49a which is arranged to monitor the amount of electricity supplied to the building 3 from the local network 15. Some buildings 3 have a two-way meter 49b, which is arranged to monitor the amount of electricity supplied to the building 3 from the local network 15 and to monitor the amount of electricity supplied from the building 3 to the local network 15. For buildings 3 having their own solar power system 39, a one-way meter 49a is typically provided to monitor the amount of electricity supplied from the solar power system 39 to the building 3. For buildings 3 having their own battery 41, a two-way meter 49b is typically provided to monitor the amount of electricity supplied to the battery 41 and to monitor the amount of electricity supplied from the battery 41 to the building 3. For buildings 3 having their own bidirectional vehicle charger 43, a two-way meter 49b is typically provided to monitor the amount of electricity supplied to the bidirectional vehicle charger 43, and to monitor the amount of electricity supplied from bidirectional vehicle charger 43 to the building 3. The site may also include a plurality of public use bidirectional vehicle chargers 51. Each bidirectional vehicle charger can have a two-way meter 49b to monitor the amount of electricity supplied to the bidirectional vehicle charger 43 from the local network, and to monitor the amount of electricity supplied from bidirectional vehicle charger 43 to the local network. Optionally, at least some of the electricity meters 47,49a,49b can be arranged to communicate wirelessly with a respective display unit. The electrical system 1 can include a one-way meter 47a arranged to monitor the supply of electricity from the waste plant 14 to the local network 15. The electrical system 1 can include a one-way meter 47a arranged to monitor the supply of electricity from the wind power system 19 to the electrolyser 31. The electrical system 1 can include a one-way meter 47a arranged to monitor the supply of electricity from the fuel cell 29 to the local network 15. The electrical system 1 can include a one-way meter 47a arranged to monitor the supply of electricity from the auxiliary power supply 23 to the battery 4. The electrical system 1 can include a one-way meter 47a arranged to monitor the supply of electricity from the wind power system 19 to the battery 4. In some embodiments, the electrical system 1 can include a one-way meter 47a arranged to monitor the electrical output from the wind power system 19. The electrical system 1 can include a one-way meter 47a arranged to monitor the supply of electricity from the solar power system 21 to the battery 4. The electrical system 1 can include a one-way meter 47a arranged to monitor the supply of electricity from the solar power system 21 to the local network 15. In some embodiments, the electrical system 1 can include a one-way meter 47a arranged to monitor the electrical output from the solar power system 21. The electrical system 1 can include a two-way meter 47b arranged to monitor the supply of electricity from the battery 4 to the local network 15, and to monitor the supply of electricity to the battery 4. The electrical system 1 can include a one-way meter 47a arranged to monitor the supply of electricity from the AC generator 24 to the local network 15. In some embodiments electricity can be exported from at least one building 3 to the local network 15 for use on the local network 15, for example by other buildings 3. In some embodiments, electricity from the local network 15 can be exported to the mains grid 17. The group of buildings 3 can include a heating network. The heating network can include heat pumps, for example ground source heat pumps and / or air source heat pumps, at least one heat source, such as a hot water tanks, and where available waste heat from heat sources such as waste plants 14, data centres 13, factories 11, etc. The building 3 can be connected to the heating network and receive at least some heat from the heating network. Buildings 3 may also have their own heating systems, which can supplement heat received form the heating network. The electrical system 1 includes a control system 53. The control system 53 can include at least one programable logic controller. At least some aspects of the control system can be programmed into a general purpose computer. Each electricity meter 47,49a,49b is arranged to communicate with the control system 53, for example wirelessly, and the control system 53 is arranged to monitor electricity usage across the electrical system 1 from the signals received from the electricity meters 47,49a,49b. The control system 53 is arranged to control operation of the battery 4, including charging of the battery 4 and supplying electricity from the battery 4 to the local network 15. For example, the battery 4 can be used to supply electricity to the local network 15 when the control system 53 determines that the electrical power supplied to the local network 15 is insufficient to meet the needs of the buildings 3, for example due to a sharp rise in demand or a failure of electrical supply by at least one of the mains supply 17, wind power system 19 and solar power system 21. The control system 53 is arranged to control operation of the wind power system 19 to selectively supply electricity to charge the battery 4. The control system 53 is arranged to control operation of the solar power system 21 to selectively supply electricity to charge the battery 4. The control system 53 is arranged to control operation of the auxiliary power supply 23, to selectively supply electricity to charge the battery 4, for example when the electrical supply from the wind power system 19 and solar power system 21 is insufficient to fully charge the battery 4 within a predetermined period of time. When the output from the solar and wind power supplies 19,21 is insufficient to charge the battery 4 to its maximum state of charge within the predetermined period of time, the control system 53 actuates biodiesel generator, to help make up the electrical supply shortfall. When the electrical supply from the wind power system 19 and solar power system 21 is insufficient to fully charge the battery 4 within a predetermined period of time, the control system 53 can be arranged to charge the battery 4 from the mains supply 17, as an alternative to the auxiliary power supply 23, or in addition to the auxiliary power supply 23. Figure 2 shows how the control system 53 is connected, either by a wired or wireless connection, to at least the following: the buildings 3, battery 4, auxiliary supply 23, AC generator 24, solar power system 21, wind power system 19, the long-term energy storage system 25, waste from heat plant 14, transport hub 33, bidirectional chargers 37. The control system 53 is arranged to receive weather alerts. The weather alerts can include weather data regarding the weather conditions in the vicinity of the group of buildings 3. The weather data can include estimates for certain weather parameters, such as temperature, windspeeds, sunlight, and precipitation such as rainfall and snowfall, during a forecast period. The weather alert can indicate the time the weather conditions are likely to occur and the duration of the weather conditions. The control system 53 is able to determine from the weather data if a bad weather event is likely to occur during the forecast period, when the bad weather is likely to arrive and how long the bad weather is like to last. Thus the control system 53 is able to determine a charging period, wherein the charging period is the period of time available to charge the battery 4 before the bad weather arrives at the group of buildings 3. The control system 53 can be arranged to determine from the weather alert that the temperature in the vicinity of the group of buildings is forecast to drop below a low temperature threshold value or to exceed a high temperature threshold value. The low temperature threshold value can be, for example 4°C, 3°C, 2°C, 1°C, 0°C, -1°C, -2°C, -3°C, or -4°C. Other suitable values for the low temperature threshold value can be selected according to electrical system set up, and typical temperatures experienced in the vicinity of the group of buildings. For example, in cold countries, and electrical systems that are set up for the cold, the low temperature threshold value can be, for example -20°C, -21 °C, -22°C, -23°c -24°C, -25°C. In response to receiving a weather alert, which indicates that the temperature in the vicinity of the group of buildings is forecast to drop below a low temperature threshold value, the control system 53 can be arranged to charge the battery 4, preferably to a maximum state of charge prior to the low temperatures occurring, that is within the charging period. Additionally, or alternatively, in response to receiving a weather alert, which indicates that the temperature in the vicinity of the group of buildings is forecast to drop below a low temperature threshold value, the control system 53 can be arranged to activate a heating system to heat a heat storage tank 60 prior to the low temperatures occurring. This helps to reduce the electrical load during the bad weather event. The control system 23 can determine from the weather alert if the temperature in the vicinity of the group of buildings 3 is forecast to rise above a high temperature threshold value. The high temperature threshold value can be, for example 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C or 40°C. Other suitable values for the high temperature threshold value can be selected according to electrical system set up, and typical temperatures experienced. For example, in hot countries the high temperature threshold value can be, for example 45°C, 46°C, 47°C, 48°C, 49°C or 50°C. The weather alert can include the temperature(s) forecast for the group of buildings 3. In response to receiving a weather alert, which indicates that the temperature in the vicinity of the group of buildings 3 is forecast to exceed the high temperature threshold value, the control system 53 can be arranged to charge the battery 4, preferably to a maximum state of charge prior to the high temperatures occurring, that is within the charging period. In response to receiving a weather alert, which indicates that the temperature in the vicinity of the group of buildings 3 is forecast to exceed a high temperature threshold value, the control system 53 can be arranged to activate a cooling system to cool a cold storage tank prior to the high temperature occurring. This helps to reduce the electrical load during the bad weather event. The control system 53 can is arranged to determine from the weather alert if rainfall in the vicinity of the group of buildings 3 is forecast to be greater than a rainfall threshold value. The control system 53 is arranged to determine from the weather alert if snowfall in the vicinity of the group of buildings 3 is forecast to be greater than a snowfall threshold value. The control system 53 is arranged to determine from the weather alert if the windspeed in the vicinity of the group of buildings 3 is forecast to be greater than a windspeed threshold value. The weather alert can include a clear notification, which indicates that a bad weather event will occur in the forecast period. The weather alert can be provided to the control system 53 by any suitable electronic means. For example, the weather alert can be provided to the control system 53 by email, short-message-service message (text message), via an Application Programming Interface (API), which provides access to weather data and alerts database via a network connection, a radio signal issued by a weather alert service, which is received at a receiver connected to the control system. The control system 53 can also include a Human Machine Interface (HMI) to enable a user to provide a weather alert to the control system 53 manually. Weather alerts can be sent together with regular weather data and / or can be sent separately from the weather data received by the control system. For example, the control system 53 can be arranged to receive weather alerts containing weather data on a periodic basis. The control system can also receive additional weather alerts between periodic weather alerts, which provide weather updates, for example if the weather is changing rapidly. In some embodiments, the control system 53 is arranged to determine a charging strategy for charging the battery 4 prior to the bad weather arriving at the group of buildings. For example, the control system 53 can be arranged to determine a charging strategy for charging the battery 4 to a maximum state of charge within the charging period, or a charging strategy to charge the battery 4 to the greatest charge achievable within the charging period. The control system 53 is typically arranged to prioritise charging of the battery 4 with at least one of the solar power system 21 and the wind power system 19 during the charging period. This helps to ensure a maximum use of renewable energy to charge the battery 4. For example, the control system 53 can be arranged to estimate the total electrical energy output from the solar power system 21 prior to the bad weather arriving at the group of buildings 3, based on the available sunlight forecast in the weather data, and to formulate the charging strategy, at least in part, based on the estimated electrical energy output from solar power system 21 during the charging period. For example, in some scenarios, the solar power system 21 may generate sufficient electrical energy to fully charge the battery 4 prior to the bad weather arriving. In other scenarios, the solar power system 21 may generate a proportion of the electrical energy required to fully charge the battery 4 prior to the bad weather arriving. For example, in some scenarios the solar power system 21 may generate around 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or less than 10%, of the energy required to fully charge the battery 4 prior to the bad weather arriving. The control system 53 can be arranged to estimate the total electrical energy output from the wind power system 19 prior to the bad weather arriving at the group of buildings 3, based on the available windspeed forecast in the weather data, and to formulate the charging strategy, at least in part, based on the estimated electrical energy output from wind power system 19 during the charging period. For example, in some scenarios, the wind power system 19 may generate sufficient electrical energy to fully charge the battery 4 during the charging period. In other scenarios, the wind power system 19 may generate a proportion of the electrical energy required to fully charge the battery 4 prior to the bad weather arriving. For example, in some scenarios the wind power system 19 may generate around 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or less than 10%, of the energy required to charge the battery 4 prior to the bad weather arriving. The control system 53 can produce a charging strategy that includes supplying electricity to the battery 4 from the auxiliary supply 23, for example to make up at least a proportion of any shortfall in electrical supply from the solar power system 21 and / or the wind power system 19. For example, in some scenarios the auxiliary power system 23 may generate around 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or less than 10%, of the energy required to charge the battery 4 prior to the bad weather arriving. The control system 53 can produce a charging strategy that includes supplying electricity to the battery 4 from the mains power supply 17, for example to make up at least a proportion of any shortfall in electrical supply from the solar power system 21 and / or the wind power system 19 during the charging in period. For example, in some scenarios the mains power supply 17 may generate around 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or less than 10%, of the energy required to charge the battery 4 prior to the bad weather arriving. The control system 53 can be arranged to select between the auxiliary power supply 23 and the mains power supply 17 during the period prior to the bad weather arriving according to at least one parameter. For example the control system 53 can determine the availability of the auxiliary power supply 23 and / or the mains power supply 17 during the charging period, or the remaining portion of the charging period. For example, an absence of an electrical signal from the auxiliary power supply 23 to the control system 53 can indicate a lack of availability of the auxiliary power supply 23, due to a lack of fuel, or difficulties in activating the auxiliary power supply 23 from a dormant state. An absence of an electrical signal from the mains power supply 17 to the control system can indicate a lack of availability of the mains supply 17, for example due to a fault in the mains power supply system. Additionally, or alternatively, the control system 53 can be arranged to select between the auxiliary power supply 23 and the mains power supply 17 according to an estimated cost of supply value for each of the mains power supply 17 and the auxiliary power supply 23. For example, the control system 53 can be arranged to give priority to the power supply 17,23 that can provide the required electrical energy to the battery 7 at the lowest cost. In at least one operational condition, the control system 53 can continue to charge the battery 4 after the arrival of the bad weather at the group of buildings 3. The control system 53 is arranged to estimate the total amount of electrical energy the group of buildings 3 is likely to require for normal operation of the buildings 3 for the period of the bad weather event. The control system 53 can use historical electrical load data for each building 3, and the knowledge of the duration and timing of the bad weather event, to estimate the electrical energy required for each building 3 during normal operation for the equivalent period for the bad weather event. The control system 53 is also arranged to adjust the estimate for the total amount of electrical energy the group of buildings 3 is likely to require during normal operation of the buildings 3 for the period of the bad weather event, for example to account for the conditions likely to be experienced during the bad weather event. For some types of bad weather events, the historical data for an equivalent period for the bad weather event can be adjusted by a bad weather factor to take account of potential additional usage of electricity, e.g. increased temperature settings on heating systems or air conditioning units, due to the nature of the bad weather event. The estimate can be adjusted by adding an amount of expected additional energy requirement. The estimate can be adjusted by subtracting an amount of expected additional energy requirement. The control system 53 can include a machine learning system that is arranged to modify the estimate for the total amount of electrical energy the group of buildings 3 is likely to require during normal operation of the buildings for the period of time that coincides with the period for the bad weather event. Over a period of time, the learning system can capture data regarding the impact that each bad weather event had on electrical consumption, and the machine learning system can learn to provide more accurate bad weather adjustments for the electrical consumption based on different types and severity of bad weather events. In the event that the energy supplied by the solar power system 21 and / or wind power system 19 to the consumer units is insufficient to meet the electrical needs of all of the buildings 3 for the duration of the bad weather event, the control system 53 is arranged to supplement the electrical energy supplied to the consumer units by supplying the consumer units with electricity from the battery 4. From the weather data provided, the control system 53 is able to estimate the amount of electrical energy that will be generated by the solar power system 21 and the wind power system 19 during the bad weather event. From the estimate of the amount of electrical energy that will be generated by the solar power system 21 and the wind power system 19 during the bad weather event, the control system 53 is able to estimate if sufficient electrical power will be available from the battery 4, solar power system 21 and wind power system 19 to meet the load requirements for the buildings 3 during the bad weather event. In the event that the energy supplied by the solar power system 21, wind power system 19 and battery 4 to the consumer units is insufficient to meet the needs of all of the buildings 3 for the duration of the bad weather event, the control system 53 is arranged to supplement the electrical energy supplied to the consumer units by supplying the consumer units with electricity from at least one of: the fuel cell 29, the electric vehicle batteries, the mains power supply 17, and the AC generator 24. The control system 53 can check the availability of the electrical power supplies, and then determine a suitable strategy for balancing the supply and load. The control system 53 is arranged to export excess electricity to the grid 17. In use, the control system 53 can be programmed to follow one or more decision algorithms in order to control charging of the battery 4 and to provide electricity to the consumer units. At least one of those algorithms provides an approach for dealing with a weather alert that indicates that bad weather if forecast in the vicinity of the buildings 3. At least one of those algorithms provides an approach for dealing with normal operation of the electrical system in fair weather conditions. Figures 7a to 7c show an algorithm for controlling operation the electrical system 1 after a weather alert has been received 100, which indicates that bad weather if forecast in the vicinity of the buildings 3. In response to receiving the bad weather alert, the control system estimates 102,104 the likely electrical demand required for each building 3 during the bad weather event, for example based on historical demand data for each building for an equivalent time period for the bad weather event. For example, if the bad weather event takes place from Friday to Monday during early November, historical electrical demand data for an equivalent period can be used to make an initial estimate for the amount of electrical energy that is likely to be required. This initial estimate does not take into account the bad weather conditions. The control system 53 then adjusts 106,108 the estimated demand value determined by steps 102,104 using a machine learning system to account for the bad weather event. For example, if the bad weather event relates to low temperatures, an adjustment is made for the likely extra demand that will be required due to the lower temperatures, for example for due to supplemental heating, boiling kettles for hot drinks etc. The control system 53 determines the likely output 110 from the solar power system 21 and the wind power system 19, based on the available sunlight during the bad weather event and the available wind speeds during the bad weather event. If the generation output is likely to meet 111 buildings demand, then the site needs are met. If the generation outputs is unlikely to meet the demand, then the control system 53 determines 112 if generated electricity + the current state of charge in the battery 4 will meet the demand, if so the site needs are met. If not, the control system 53 charges the battery 4 and any additional storage devices 114 for the buildings 3, for example local batteries at houses, commercial and industrial and site wide, including using a heating device such as a heat pump to charge any thermal storage units, prior to the bad weather arriving. The control system 53 may also send control signals to the buildings 3 to control operation of electric vehicle chargers to limit peak use (EV enabler schedule), and to charge up the electric vehicle via the bidirectional charger, which are signed up to the scheme. The control system 53 determines the charging period based on data received in the weather alert. To charge the available energy stores 4, the control system 53 determines the likely output from the solar power system 21 and the wind power system 19, based on the available sunlight during the charging period and the available wind speeds during the charging period, and determines if the solar power system 21 and wind power system 19 are able to fully charge the battery 4 during the charging period. If this is possible, the control system 53 charges the battery 4 to its maximum capacity within the charging period using the solar power system 21 and wind power system 19. If the wind power system 19 and solar power system 21 or not able to charge the battery 4 to its maximum capacity within the charging period, the control system 53 actuates the auxiliary power supply 23, or uses the mains power supply 17, to top up the charge of the battery 4 during the charging period. The control system 53 monitors the state of charge of the battery 4, and any other available storage devices. The control system 53 then determines 116 whether the combined electrical output from the solar power system 21, wind power system 19, battery 4 and any other available energy stores can meet the demand during the bad weather period, or for at least a predetermined period such as 24 hours. The control system 53 determines 117 if repeating the above steps for a subsequent predetermined period, for example a subsequent 24hr period. If yes, the site needs are deemed to be met. If not, the control system 53 calculates 119 the electrical supply shortfall, and then the control system 53 actuates 118,120 at least one additional source of electricity to supply electricity to the local network 15, and the consumer units, to ensure that electrical demand from the buildings is met during the bad weather event, or at least two predetermined periods of time, such as a 48 hour period. The additional sources of electricity can include one or more of: the AC generator 24 for example as a peaker, energy from waste plant 14 as base load, electric vehicle batteries and the fuel cell 29. If the energy from waste plant 14 cannot provide sufficient based load during the relevant time period, the long-term energy store 25 can be actuated 122 to top up any shortfall. In some circumstances, the control system 53 may use electricity from the mains supply 17 to ensure that demand is met during the bad weather event. In this manner, electricity can be mainly supplied to the buildings 3 during a bad weather event by solar and wind power 21,19 if those sources are available, however backup supplies are also provided to meet any shortfall in supply. The control system 53 can repeat this process periodically to ensure that the electrical demand is met throughout the duration of the bad weather event. For example, updated weather alerts may indicate that the bad weather event is more or less severe than originally reported, or that the bad weather event will last for a shorter period of time or a longer period of time. Repeating the process helps to ensure that electrical sources are used efficiently. Figures 9a and 9b show an algorithm for controlling operation the electrical system 1 after a weather alert has been received 200, which indicates that there is a bad weather event forecast within the forecast period. The algorithm focuses on heat storage. In response to receiving the bad weather alert 200, the control system estimates 202,204 the likely electrical demand required for each building 3 during the bad weather event, for example based on historical demand data for each building for an equivalent time period for the bad weather event. For example, if the bad weather event takes place from Friday to Monday during early November, historical electrical demand data for an equivalent period can be used to make an initial estimate for the amount of electrical energy that is likely to be required. The estimate can take into account yesterday’s temperature, yesterday’s heat demand for the buildings, and tomorrow's temperature. The control system 53 estimates the expected heat demand 206 from the buildings 3 for a predetermined period, such as 24 hrs, for example based the data mentioned above, and checks the “state of charge” 208 (the storage state, i.e. the current amount of heat stored, for example as a percentage of the total capacity for heat storage, or as an absolute figure) of the available heat stores. The control system 53 then determines 210 from the expected heat demand and the amount of heat currently stored if there is enough stored heat to meet the heating demand for the predetermined period. If there is sufficient heat stored to meet the heating demand for the predetermined period, the control system determines 212 if there is enough stored heat to meet the heating demand for at least another predetermined period, for example a subsequent 24 hour period. If there is sufficient heat stored to meet the heating demand for two predetermined periods (e.g. 48 hours), then the control system 53 continues to monitor the situation. For example, heating demand may be higher than expected, or a new weather alert may indicate that the weather is likely to be more severe in the vicinity of the buildings than initially thought. If the control system determines 210 that there is insufficient heat stored in the thermal storage tanks to meet the heating demands for the predetermined period, the control system 53 activates 213 the heat pump to be used as a thermal store and to fill any thermal storage tanks, using heat from the heat pump and any other available sources such as heat from an energy from waste plant or data centre. By filling the thermal storage tanks to their maximum capacity, or near maximum capacity should be sufficient to meeting the heating demand of the buildings 3 for at least a predetermined period, and in some cases for at least two predetermined periods. If the control system determines 210 that there is sufficient heat stored in the thermal storage tanks to meet the heating demands for the predetermined period however that there is likely to be insufficient heat stored in the thermal storage tanks to meet the heating demands for the second predetermined period, the control system 53 determines 214 if repeating the above process for the second predetermined period will meet the demand. If so, the site needs are met. If not, the control system 53 calculates 216 how much additional heat supply is required to meet the demand that it is necessary to operate the heat pumps for an extended period of time in order to meet the heating demands. Electricity can be supplied 218,220 to the heat pumps from any suitable source within the electrical system, such as the energy from waste plant, for example as a base load, a biodiesel generator, for example as a peaker, solar power system, wind power system, fuel cell, for example if the biodiesel generator acting as peaker is insufficient to meet the electrical needs to meet heat demand, electric vehicle batteries, the energy store or mains supply. During such a period, the control system is arranged to curb 222 electricity export to the grid. Figures 4a-4b, 5a-5b, 6a-6b, 8a-8b, 10a, 10b discloses various algorithms for controlling operation of the electrical system during normal weather conditions, for example the weather data in the weather alert can show favourable weather conditions are likely in the vicinity of the buildings 3 for the forecast period, that is the forecast values of certain weather parameters, such as temperature, windspeed, rainfall and snowfall are within predetermined threshold values, and therefore the risk to electrical system 1 is low, and the risk of higher than usual electrical demand from the buildings is low. Figures 4a and 4b show an algorithm for controlling normal operation of the electrical system, with a focus on generating electricity from the solar power system 21. The control system 53 determines 300 from weather data the amount of sunshine that will be available for the forecast period. If the forecast sunlight falls below a threshold value, then the control system 53 switches 302 to another algorithm, for example an algorithm that focuses on wind generation. If the forecast sunlight is above a threshold value, the control system 53 calculates 304 the likely amount of electricity that the solar power system 21 will generate over a predetermined period of time, such as the next 24 hours. The control system 53 estimates 306,308 the likely electrical demand from each building 3 for the predetermined period of time, and calculates an estimate for the total requirement. The control system 53 accesses a database that takes into account a rolling 14 day period for electrical demand from the buildings, which can be adjusted for weekdays or weekend days. The control system sums up today’s consumption at least in part based on yesterday's consumption over time. The control system 53 then determines 312 the extent to which the electricity generated by the solar power system 21 will meet the electrical demand for the buildings 3. For example, the control system 53 may determine that the electricity generated by the solar power system 21 meets 100 %, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% or less than 10% of the electrical demand from the buildings 3. If the solar power system 21 is not able to fully meet the electrical demand from the buildings, the control system 53 selects 317 electricity from one or more additional electrical sources of electricity, for example from the battery 4, any batteries available at the buildings 3, electric vehicle batteries, thermal stores, and the longterm (inter-seasonal) energy store 25. The control system 53 determines 319 if there is sufficient electricity available from the additional sources of electricity to meet the electrical demand from the buildings. If not, the control system 53 determines 321 if there will be sufficient electrical supply when the autonomous vehicles return to base and are connected to the local network 15. If not, the control system 53 prepares one or more back up supplies, such the biodiesel generator, energy from waste plant, and possibly the mains supply to ensure that the electrical demand from the buildings is met. If the solar power system 21 is expected to meet 100% of the needs of the electrical demand from the buildings 3, the control system 53 determines 315 if this is the case for all half hour periods within the predetermined period of time (possibly supplemented by batter 4 power during night time). If the control system 53 determines 316 that the solar power system 21 is expected to exceed the electrical demand from the buildings 3, the control system 53 determines 318 what to do with the excess, for example the control system 53 can power the heat pumps 320 to store heat in the thermal store, store energy 322 in the battery 4, sell 324 electricity to the grid, power electric vehicles 326, and / or supply energy 328 to the long-term (inter-seasonal) energy store 25, for example to generate and store hydrogen. Figures 5a and 5b show an algorithm for controlling normal operation of the electrical system, with a focus on electrical storage. The control system 53 calculates 404 the likely amount of electricity that the solar power system 21 will generate over a predetermined period of time, such as the next 24 hours. The control system 53 estimates 406,408 the likely electrical demand from each building 3 for the predetermined period of time, and calculates an estimate for the total requirement. The control system 53 accesses a database that takes into account a rolling 14 day period for electrical demand from the buildings, which can be adjusted for weekdays or weekend days. The control system sums up today’s consumption at least in part based on yesterday's consumption over time. The control system 53 then determines 410 the extent to which the electricity generated by the solar power system 21, wind power system 19 and solar panels for specific buildings, will meet the electrical demand for the buildings 3. For example, the control system 53 may determine that the electricity generated meets 100 %, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% or less than 10% of the electrical demand from the buildings 3. If the electrical generation is not able to fully meet the electrical demand from the buildings, the control system 53 selects 417 electricity from one or more additional electrical sources of electricity, for example from the battery 4, any batteries available at the buildings 3. The control system 53 determines 412 if there is sufficient electricity available from the additional sources of electricity to meet the electrical demand from the buildings. If so, the site needs are met. If not, the control system 53 determines 414 if there will be sufficient electrical supply from the long-term (inter-seasonal) energy store 25. If yes, site needs are met. If not, the control system 53 determines 416 if there will be sufficient electrical supply when the autonomous vehicles return to base and are connected to the local network 15. If yes, site needs are met. If not, the control system 53 prepares one or more back up supplies, such as the long-term energy store 25, the biodiesel generator, energy from waste plant 14, and possibly the mains supply to ensure that the electrical demand from the buildings is met. If the control system 53 determines 410 that the electricity generated by the solar power system 21, wind power system 19 and solar panels for specific buildings, will meet the electrical demand for the buildings 3, the control system determines 420 if the electricity generated will cover a subsequent predetermined period, e.g. a subsequent 24 hours. If not, the control system 53 is arranged to either use cheap overnight electricity 422 from the mains or electricity from 424 the biodiesel generator to meet the electrical demand from the buildings. If the control system 53 determines 420 that the electricity generated is expected to meet the needs of the electrical demand from the buildings during the subsequent predetermined period of time, the control system 53 determines 426 if exporting to the grid provides good income, and if so, exports to the grid 428, recharging 430 the battery 4 and any other batteries whenever possible. If the control system 53 determines 420 that the electricity generated is expected to meet the electrical demand from the buildings during the subsequent predetermined period of time, and the control system 53 determines 426 that exporting to the grid does not provide good income, then the excess electrical energy can be used to top up 432 energy stores, including thermal energy stores, and / or charge the longterm storage 25, for example by producing and storing hydrogen. Figures 6a and 6b show an algorithm for controlling normal operation of the electrical system, with a focus on generating electricity from the wind power system 19. The control system 53 determines 500 from weather data the amount of wind that will be available for the forecast period. If the forecast wind falls below a threshold value, then the control system 53 switches 502 to another algorithm, for example an algorithm that focuses on solar generation, such as Figures 4a and 4b. If the forecast wind speed is above a threshold value, the control system 53 calculates 504 the likely amount of electricity that the wind power system 19 will generate over a predetermined period of time, such as the next 24 hours. The control system 53 estimates 506,508 the likely electrical demand from each building 3 for the predetermined period of time, and calculates an estimate for the total requirement. The control system 53 accesses a database that takes into account a rolling 14 day period for electrical demand from the buildings, which can be adjusted for weekdays or weekend days. The control system 53 sums up today’s consumption at least in part based on yesterday's consumption over time. The control system 53 then determines 510 the extent to which the electricity generated by the wind power system 19 will meet the electrical demand for the buildings 3. For example, the control system 53 may determine that the electricity generated by the wind power system 19 meets 100 %, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% or less than 10% of the electrical demand from the buildings 3. If the wind power system 19 is not able to fully meet the electrical demand from the buildings, the control system 53 selects 512 electricity from one or more additional electrical sources of electricity, for example from the battery 4, any batteries available at the buildings 3, electric vehicle batteries, thermal stores, and the longterm (inter-seasonal) energy store 25. The control system 53 determines 514 if there is sufficient electricity available from the additional sources of electricity to meet the electrical demand from the buildings. If yes, site needs are met. If not, the control system 53 determines 516 if there will be sufficient electrical supply when the autonomous vehicles return to base and are connected to the local network 15. If yes, site needs are met. If not, the control system 53 prepares one or more back up supplies 518, such the biodiesel generator, energy from waste plant, and possibly the mains supply to ensure that the electrical demand from the buildings is met. If the wind power system 19 is expected 510 to meet the electrical demand from the buildings 3, the control system 53 determines 520 if this is the case for all half hour periods within the predetermined period of time (possibly supplemented by batter 4 power during night time). If yes, the control system 53 determines 522 if the electricity generated will have be greater than the demand. If yes, the control system 53 determines 524 what to do with the excess, for example the control system 53 can power the heat pumps 526 to store heat in the thermal store, store energy 528 in the battery 4, sell 530 electricity to the grid, power electric vehicles 532, and / or supply energy 534 to the long-term (inter-seasonal) energy store 25, for example to generate and store hydrogen. Figures 8a and 8b show an algorithm for controlling normal operation of the electrical system, with a focus on heat storage. The control system 53 estimates the expected heat demand 600 from the buildings (e.g. homes, schools, offices, commercial &industrial (C&I)), for a predetermined period of time, such as the subsequent 24 hour period, based on calculating a standard consumption for each building for a given temperature, taking into account tomorrow’s temperature, and yesterday’s heat demand and yesterday’s temperature. The control system 53 checks the “state of charge” 602 (the storage state, i.e. the current amount of heat stored, for example as a percentage of the total capacity for heat storage) of the available heat stores. The control system 53 then determines 604 from the expected heat demand and the amount of heat currently stored if there is enough stored heat to meet the heating demand for the predetermined period. If yes, the control system determines 606 if there is enough stored heat to meet the heating demand for at least a further predetermined period, for example yet another 24 hour period. If yes, the site needs are met. If the control system 53 determines 604 that there is insufficient heat stored in the thermal storage tanks to meet the building heating demands for the period of time, or further predetermined period of time 606, the control system 53 checks the state of charge 608 of the battery 4 to determine if there is sufficient charge in the battery 4 to run the heat pump. If yes, the control system activates 610 the heat pump using energy from the battery 4 to charge up any thermal storage tanks to ensure the heat demand is met. The control system 53 can use heat from the heat pump and any other available sources such as heat from an energy from waste plant or data centre to charge the heat stores. If the control system determines 608 that there is insufficient charge stored in the battery 4 to run the heat pump to charge the thermal stores, the control system 53 activates the heat pump using the battery 4, and additionally curbs electricity export 612 to the grid and / or controls 614 building thermostats to lower their target temperatures by a predetermined amount, such as IC, and to divert energy to the thermal stores. If the control system 53 determines 614 that it is necessary to operate the heat pumps for an extended period of time in order to meet the heating demands, electricity can be supplied to the heat pumps from any suitable source within the electrical system, such as the energy from waste plant, a biodiesel generator, solar power system, wind power system, fuel cell, electric vehicle batteries, the energy store or mains supply. Figures 10a and 10b show an algorithm for controlling operation of the electrical system 1, which combines both normal operational steps for the electrical system and steps taken after a weather alert has been received, which indicates that there is a bad weather event forecast within the forecast period. The algorithm seeks to use electricity from electric vehicles to make up any shortfall in supply, in the event that the solar power system 21, wind power system 19 and battery 4 cannot meet the electrical demand from the buildings during normal weather conditions, i.e. weather conditions that fall within acceptable values for weather parameters mentioned above. In the event that the control system 53 receives a weather alert 300, which indicates that a bad weather event is likely to occur at the buildings during the forecast period. The control system 53 estimates 700 the likely electrical demand from each building 3 for the predetermined period of time, such as the next 24 hours, and calculates an estimate for the total requirement of all electrical loads. To do this, the control system calculates 702 a standard consumption for each building for a given temperature, and then adjusts 704 for the number of buildings. The control system 53 accesses a database 706 that takes into account a rolling 14 day period for electrical demand from the buildings, which can be adjusted for weekdays or weekend days. The control system sums 708 up today’s consumption at least in part based on yesterday's consumption over time. The control system 53 estimates 710 the likely electrical generation from the solar power system 21 and the wind power system 19 for the predetermined period of time. The control system 53 then determines 712 the extent to which the electricity generated by the solar power system 21 and wind power system 19, meets the electrical demand for the buildings 3. For example, the control system 53 may determine that the electricity generated meets 100 %, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% or less than 10% of the electrical demand from the buildings 3. If the electrical generation is not able to fully meet the electrical demand from the buildings, the control system 53 checks the state of charge 714 of the battery 4 to determine if there is sufficient charge in the battery 4 to make up any shortfall in the electricity generated by the wind and solar power systems 19,21. If yes, the site needs are met. Under these conditions, it is possible for the control system 53 to determine 716 that electricity from the electric vehicle batteries are not required to meet electrical demand during the predetermined period, the control system 53 then determines 718 if the export prices to the grid are high, and if so exports 720 electricity from the electric vehicles to batteries to the grid 17. If the export prices are low, no export takes place. If the state of charge 714 of the battery 4 is insufficient to make up the shortfall, the control system 53 can select 722 any other available form of electrical supply to meet the shortfall, under normal weather conditions. If the control system 53 determines from the weather alert 724 that bad weather is likely in the vicinity of the buildings 3 within the predetermined period of time, for example due to low temperatures, the control system calculates 726 the likely additional electrical demand required due to the cold weather. If the control system 53 determines from the weather alert 724 that bad weather is likely in the vicinity of the buildings 3 within the predetermined period of time, the control system 53 may switch 728 to the algorithm of Figures 7a to 7c. If the control system 53 remains with the algorithm of Figures 10a and 10b, the control system 53 determines 730 if the autonomous vehicles will return to the transport hub, and be connected to their charging points, at a time that is likely to coincide with peak electrical demand. If not, the control system charges up 732 the thermal stores ahead of peak time. If the autonomous vehicles are expected to be available at the peak electrical demand, the control system 53 determines 734 if the expected electrical supply from the autonomous vehicle batteries, is likely to meet the extra electrical demand required as a result of the bad weather. If not, the control system 53 determines not to use electricity from the autonomous vehicles. If yes, the control system 53 goes on to determine 736 if the autonomous vehicles, after having supplied electricity to the buildings 3 to meet additional electrical demand required as a result of the bad weather, will still have sufficient charge to operate, for example to go around their normal routes on the site at least once, and possibly a plurality of times. If not, the control system 53 determines not to use the automated electric vehicles to supply the buildings during the bad weather event. If yes, the control system 53 selects the automated electric vehicles to supply electricity to the buildings during the bad weather event, measures the amount of electricity supplied and credits the vehicle owner’s account. If necessary, the control system 53 can move 738 autonomous vehicles down the supply selection hierarchy switch to other algorithms 740 thereby making use of other available sources of electricity. The description presents exemplary embodiments and, together with the drawings, serves to explain principles of the invention. However, the scope of the invention is not intended to be limited to the precise details of the embodiments, since variations will be apparent to a skilled person and are deemed also to be covered by the claims. Terms for components used herein should be given a broad interpretation that also encompasses equivalent functions and features. In some cases, several alternative terms (synonyms) for structural features have been provided but such terms are not intended to be exhaustive. Descriptive terms should also be given the broadest possible interpretation; e.g., the term "comprising" as used in this specification means "including" such that interpreting each statement in this specification that includes the term "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner. Directional terms such as “vertical”, “horizontal”, “up”, “down”, “upper” and “lower” may be used for convenience of explanation usually with reference to the illustrations and are not intended to be ultimately limiting if an equivalent function can be achieved with an alternative dimension and / or direction. The description herein refers to embodiments with particular combinations of configuration steps or features, however, it is envisaged that further combinations and cross-combinations of compatible steps or features between embodiments will be possible. Indeed, isolated features may function independently as an invention from other features and not necessarily require implementation as a complete combination. Any feature from an embodiment can be isolated from that embodiment and included in any other embodiment. The term “at least one of’ is to be interpreted in the sense of “and / or”. For example, the term “at least one of X and Y” is to be interpreted as meaning any one of the following: X alone; Y alone; or the combination of X and Y. As another example, the term “at least one of X, Y and Z” is to be interpreted as meaning any one of the following: X alone; Y alone; Z alone; 5 the combination of X and Y; the combination of transmission X and Z; the combination of Y and Z; or the combination of X, Y, Z.

Claims

1. An electrical supply system for a group of buildings, wherein each building in the group of buildings includes a consumer unit, the electrical supply system including:an energy store that is arranged to supply electricity to the consumer unit for each building in the group of buildings, in at least one operational condition;at least one electrical supply source that is arranged to charge the energy store, in at least one operational condition; anda control system arranged to monitor the state of charge of the energy store and to receive weather alerts, wherein, in response to receiving a weather alert that indicates that bad weather is likely to occur within the vicinity of the group of buildings within a forecast period, the control system is arranged to control operation of the at least one electrical supply source to increase the state of charge of the energy store prior to the bad weather arriving at the group of buildings.

2. An electrical supply system for a group of buildings, wherein each building in the group of buildings includes a consumer unit, the electrical supply system including:an energy store that is arranged to supply electricity to the consumer unit for each building in the group of buildings, in at least one operational condition;a solar power system for converting solar energy into electrical energy, wherein the solar power system is arranged to supply electricity to the energy store, in at least one operational condition;a wind power system for converting wind energy into electrical energy, wherein the wind power system is arranged to supply electricity to the energy store, in at least one operational condition;an auxiliary power supply and / or a mains power supply, wherein at least one of the auxiliary power supply and the mains power supply is arranged tosupply electricity to the energy store, in at least one operational condition; anda control system arranged to monitor the state of charge of the energy store and to receive alerts relating to bad weather in the vicinity of the group of buildings, wherein, in response to receiving a bad weather alert, the control system is arranged to control operation of at least one of the solar power system, wind power system, auxiliary power supply and mains power supply to increase the state of charge of the energy store prior to the bad weather arriving at the group of buildings.

3. The electrical supply system of any one of the preceding claims, wherein the control system is arranged to determine a charging period, wherein the charging period is the period of time available to charge the energy store before the bad weather arrives at the group of buildings.

4. The electrical supply system of claim 3, when dependent on claim 3, wherein the control system is arranged to determine the charging period from the estimated time of arrival of the bad weather, at the group of buildings, in the weather alert.

5. The electrical supply system of any of the preceding claims, wherein the control system is arranged to charge the energy store to a maximum state of charge prior to the bad weather arriving at the group of buildings, or to at least charge the energy store to the greatest charge achievable prior to the bad weather arriving at the group of buildings.

6. The electrical supply system of any of the preceding claims, wherein the control system is arranged to determine a charging strategy for charging the energy store prior to the bad weather arriving at the group of buildings.

7. The electrical supply system of claim 6, wherein the control system is arranged to prioritise charging of the energy store with at least one of the solar power system and the wind power system prior to the bad weather arriving at the group of buildings.

8. The electrical supply system of any one of the preceding claims, wherein the control system is arranged to receive weather forecast data.

9. The electrical supply system of claim 8, when dependent on claim 6, wherein the weather forecast data includes data regarding available sunlight over a forecast period in the vicinity of the solar power system, and the control system is arranged to estimate the total electrical energy output from the solar power system prior to the bad weather arriving at the group of buildings, and to formulate the charging strategy, at least in part, based on the estimated electrical energy output from solar power system.

10. The electrical supply system of claim 8 or 9 when dependent on claim 6, wherein the weather forecast data includes data regarding wind speed over a forecast period in the vicinity of the wind power system, and the control system is arranged to estimate the total electrical energy output from the wind power system prior to the bad weather arriving at the group of buildings, and to formulate the charging strategy, at least in part, based on the estimated electrical energy output from wind power system.

11. The electrical supply system of claim 9 or 10, when dependent on claim 6, wherein the charging strategy includes supplying electricity to the energy store from the auxiliary supply, for example to make up at least a proportion of any shortfall in electrical supply from the solar power system and / or the wind power system prior to the bad weather arriving at the group of buildings.

12. The electrical supply system of any one of claims 9 to 11, wherein the charging strategy includes supplying electricity to the energy store from the mains power supply, for example to make up at least a proportion of any shortfall in electrical supply from the solar power system and / or the wind power system during the charging in period.

13. The electrical supply system of claim 11 or 12, wherein the control system is arranged to select between the auxiliary power supply and the mains power supply during the period prior to the bad weather arriving according to at least one parameter.

14. The electrical supply of claim 13, wherein the at least one parameter includes the control system determining the availability of the auxiliary power supply and / or the mains power supply during the charging period, or the remaining portion of the charging period.

15. The electrical supply system of claim 13 or 14, wherein the at least one parameter includes the control system being arranged to select between the auxiliary power supply and the mains power supply according to an estimated cost of supply value for each of the mains power supply and the auxiliary power supply.

16. The electrical supply system of any one of the preceding claims, wherein the auxiliary power supply comprises a generator, and preferably a biodiesel generator.

17. The electrical supply system of any one of the preceding claims, wherein the energy store comprises at least one electrochemical cell.

18. The electrical supply system of any one of the preceding claims, wherein control system can be arranged to continue to charge the energy store after the arrival of the bad weather at the group of buildings, in at least one operational condition.

19. The electrical supply system of any one of the preceding claims, wherein control system is arranged to discharge at least some electrical energy from the energy store to the consumer units at peak demand times and / or loss of supply from at least one of the solar power system, wind power system and mains power supply, in at least one operational condition.

20. The electrical supply system of any one of the preceding claims, wherein the control system is arranged to determine from the weather alert that the temperature in the vicinity of the group of buildings is forecast to drop below a low temperature threshold value or to exceed a high temperature threshold value.

21. The electrical supply system of any one of the preceding claims, wherein the control system is arranged to determine from the weather alert, if rainfall in the vicinity of the group of buildings is forecast to be greater than a rainfall threshold value; and / or the control system is arranged to determine from the weather alert if snowfall in thevicinity of the group of buildings is forecast to be greater than a snowfall threshold value; and / or the control system is arranged to determine from the weather alert if the windspeed in the vicinity of the group of buildings is forecast to be greater than a windspeed threshold value.

22. The electrical supply system of any one of the preceding claims, including a longterm energy store, wherein the control system is arranged to control actuation of the long-term energy store to selectively supply electricity to at least one of: the consumer units and the energy store23. The electrical supply system of claim 22, wherein the long-term energy store comprises a fuel cell.

24. The electrical supply system of claim 22 or 23, wherein the long-term energy store comprises a hydrogen store.

25. The electrical supply system of any one of claims 22 to 24, wherein the long-term energy store comprises an electrolyser, which is arranged to produce hydrogen.

26. The electrical supply system of any one of the preceding claims, including at least one electrical vehicle having a rechargeable battery, and a two way electrical charger, wherein the two way electrical charger is arranged to, in at least one operational condition, supply electricity from the electric vehicle rechargeable battery, wherein the control system, in response to receiving the weather alert, is arranged to charge the electric vehicle rechargeable battery to a maximum state of charge prior to the bad weather arriving, or to the maximum state of charge that can be achieved prior to the bad weather arriving, and to supply electricity from the electric vehicle rechargeable battery to the consumer units during the bad weather event.

27. The electrical supply system of claim 26, including a plurality of electrical vehicles and a plurality of two way electrical chargers, wherein the control system, in response to receiving the weather alert, is arranged to charge each electric vehicle rechargeable battery to a maximum state of charge prior to the bad weather arriving, or to the maximum state of charge that can be achieved prior to the bad weather arriving, andto supply electricity from each electric vehicle rechargeable battery to the consumer units during the bad weather event.

28. The electrical supply system of claim 26 or 27, wherein at least one, and preferably a plurality of the electric vehicles are autonomous vehicles.

29. The electrical supply system of any one of the preceding claims, wherein the solar power system includes an arrangement of photovoltaic modules., and preferably each building, can include at least one photovoltaic module.

30. The electrical supply system of claim 29, wherein the solar power system includes a floating solar power system.

31. The electrical supply system of any one of the preceding claims, wherein the wind power system includes an arrangement of wind turbines.

32. The electrical supply system of any one of the preceding claims, including at least one DC / AC invertor, to enable electricity generated by the wind power system and / or solar power system and / or supplied by the energy store to be converted to an AC for supply to the consumer units.

33. The electrical supply system of any one of the preceding claims, wherein the control system is arranged to estimate the total amount of electrical energy the group of buildings is likely to require for normal operation of the buildings for the period of time that coincides with the period for the bad weather event.

34. The electrical supply system of claim 33, wherein the control system is arranged to adjust the estimate for the total amount of electrical energy the group of buildings is likely to require during normal operation of the buildings for the period of time that coincides with the period for the bad weather event, for example to account for the conditions likely to be experienced during the bad weather event.

35. The electrical supply system of claim 34, including a machine learning system that is arranged to modify the estimate for the total amount of electrical energy the group of buildings is likely to require during normal operation of the buildings for the period of time that coincides with the period for the bad weather event.

36. The electrical supply system of claim 34 or 35, wherein, in the event that the energy supplied by the solar power system and / or wind power system to the consumer units is insufficient to meet the needs of all of the buildings for the duration of the bad weather event, the control system is arranged to supplement the electrical energy supplied to the consumer units by supplying the consumer units with electricity from the energy store.

37. The electrical supply system of claim 36, wherein in the event that the energy supplied by the solar power system, wind power system and energy store to the consumer units is insufficient to meet the needs of all of the buildings for the duration of the bad weather event, the control system is arranged to supplement the electrical energy supplied to the consumer units by supplying the consumer units with electricity from at least one of: the long-term energy store, the electric vehicle batteries, the AC generator and the mains power supply.

38. The electrical supply system of any one of the preceding claims, wherein the consumer unit for each building has a first part and a second part, wherein essential loads are connected to the first part of the consumer unit and non-essential loads are connected to the second part of the consumer unit.

39. The electrical supply system of claim 38, wherein, during a bad weather event, the control system is arranged to supply electricity only to the first part of the consumer unit.

40. The electrical supply system of any one of the preceding claims, wherein the control system selects a given electrical supply system based on a hierarchy of electrical supply systems, wherein a given electrical supply system can move within the hierarchy according to operational conditions.

41. A method of supplying electricity to a group of buildings, wherein each building in the group of buildings includes a consumer unit, the method including:providing an electrical supply system for the group of buildings, having:an energy store that is arranged to supply electricity to the consumer unit for each building in the group of buildings, in at least one operational condition;a solar power system for converting solar energy into electrical energy, wherein the solar power system is arranged to supply electricity to the energy store, in at least one operational condition;a wind power system for converting wind energy into electrical energy, wherein the wind power system is arranged to supply electricity to the energy store, in at least one operational condition;an auxiliary power supply and / or a mains power supply, wherein at least one of the auxiliary power supply and the mains power supply is arranged to supply electricity to the energy store, in at least one operational condition; anda control system arranged to monitor the state of charge of the energy store;the control system receiving a weather alert relating to bad weather in the vicinity of the group of buildings within a forecast period;the control system, in response to receiving a weather alert, controlling operation of at least one of the solar power system, wind power system, auxiliary power supply and mains power supply to increase the state of charge of the energy store prior to the bad weather arriving at the group of buildings.

42. A control system for an electrical supply system for a group of buildings, wherein each building in the group of buildings includes a consumer unit, and the electrical supply system includes:an energy store that is arranged to supply electricity to the consumer unit for each building in the group of buildings, in at least one operational condition;a solar power system for converting solar energy into electrical energy, wherein the solar power system is arranged to supply electricity to the energy store, in at least one operational condition;a wind power system for converting wind energy into electrical energy, 5 wherein the wind power system is arranged to supply electricity to the energystore, in at least one operational condition;an auxiliary power supply and / or a mains power supply, wherein at least one of the auxiliary power supply and the mains power supply is arranged to supply electricity to the energy store, in at least one operational condition;10 andwherein, the control system is arranged to monitor the state of charge of the energy store and to receive weather alerts, wherein, in response to receiving a weather alert that indicates that bad weather is likely to occur within the vicinity of the group of buildings within a forecast period weather alert, the control system is arranged to control operation15 of at least one of the solar power system, wind power system, auxiliary power supply and mains power supply to increase the state of charge of the energy store prior to the bad weather arriving at the group of buildings.

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