Providing aggregated balancing capacity to a grid

Abstract

Disclosed is a method for balancing a grid (100), the method comprising: determining an aggregation that comprises a group of individual balancing units, wherein each balancing unit provides capacity for a reserve market, and wherein the capacity comprises ability to adjust consumption and / or production of electricity of at least one reserve unit comprised in the individual balancing unit, observing a trigger, wherein the trigger indicates a need to balance the grid, determining, based on the trigger, a balancing action for the aggregation, and performing the balancing action within the aggregation.

Description

[0001] PROVIDING AGGREGATED BALANCING CAPACITY TO A GRID

[0002] FIELD

[0003] The present disclosure relates to balancing consumption in a grid when production varies.

[0004] BACKGROUND

[0005] Renewable energy such as wind power and solar power provide clean energy to a grid. While clean energy has many benefits, there is also a dependency on weather that affects the amount of energy available at any given time. In other words, the energy production is not constant. This varying availability requires a grid to be balanced as in the grid, the consumption and production are to be in a balance at all times.

[0006] BRIEF DESCRIPTION

[0007] The scope of protection sought for various embodiments is set out by the independent claims. Dependent claims define further embodiments included in the scope of protection. The embodiments and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the disclosure.

[0008] According to a first aspect there is provided: a method for balancing a grid, the method comprising: determining an aggregation that comprises a group of individual balancing units, wherein each balancing unit provides capacity for a reserve market, and wherein the capacity comprises ability to adjust consumption and / or production of electricity of at least one reserve unit comprised in the individual balancing unit, observing a trigger, wherein the trigger indicates a need to balance the grid, determining, based on the trigger, a balancing action for the aggregation, and performing the balancing action within the aggregation.

[0009] According to a second aspect there is provided a control unit for balancing a grid, the control unit comprising at least one computing device, means for creating and coordinating an aggregation of a plurality of balancing units, wherein the aggregation is for providing a reserve for balancing actions required by a grid, means for establishing and having a connection to one or more balancing units comprised in the aggregation, wherein the balancing units are configured to provide reserve capacity that can be activated as a response to a balancing action, means for receiving a trigger, wherein the trigger indicates a deviation of a frequency of the grid from its nominal value and / or a need for the balancing action, and means for performing a method according to the first aspect.

[0010] According to a third aspect there is provided computer program product comprising instructions, which, when executed by a computing device, cause the computing device to perform a method according to the first aspect.

[0011] BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The invention is described in detail by means of specific embodiments with reference to the enclosed drawings, in which:

[0013] Figure 1 illustrates an exemplary embodiment of a grid.

[0014] Figure 2 illustrates a flow chart according to an exemplary embodiment in which the capacity of a domestic building is evaluated in terms of the building acting as a balancing unit in an aggregated group.

[0015] Figure 3A illustrates an exemplary embodiment in which the frequency of a grid is a trigger for performing a balancing action in an aggregation of balancing units.

[0016] Figure 3B illustrates an exemplary embodiment of distributed balancing of a grid.

[0017] Figure 4 illustrates a flow chart according to an exemplary embodiment in which the balancing action(s) are determined during the balancing time period for which the aggregations were determined.

[0018] Figure 5 illustrates an exemplary embodiment of a computing device.

[0019] DETAILED DESCRIPTION

[0020] Electricity is one of the basic necessities used by people every day. Electricity is required in normal day-to-day life and in various types of industrial activities. Availability of electricity may thus be considered as one of the basic requirements of society. Figure 1 illustrates an exemplary embodiment of a grid 100, that may also be referred to as an electrical grid, electricity grid, or power grid. The grid 100 comprises elements of producing electricity, transmission of the electricity and then consuming electricity by different types of consumption units. In other words, the grid 100 comprises generation of electricity, and also transmission and distribution of the generated electricity.

[0021] The electricity may be generated by different types of power plants. The power plants may be based on renewable energy such as wind power 102, or solar power 104, or the power plants may be based on for example nuclear power 106, or coal. The generated electricity is then transmitted using power lines 110. The power lines 110 transmit the generated electricity by utilizing high voltages. These high voltages are then dropped before distributing the electricity to consumption units. The consumption units may be for example households 130, 131, 132, 133, 134, 135, 136, or industrial sites 125 or office buildings 120 or any other unit that electricity is provided for to meet end user demands. It is to be noted though that some consumption units may also act as production units. For example, in case a building is associated with charging stations for one or more electric vehicles (EVs), the electric vehicles may consume electricity, but could also act as a storage for electricity such that the electricity stored in the batteries could also be provided back to the grid when the EV itself does not currently need it. For example, the office building 120 may have several charging stations for electric vehicles 140 and as the EVs most likely are there to charge themselves, the EVs could act as part of electricity consumption unit. Yet, the household 134 is associated with charging of an EV 142 and the household 135 is associated with charging of the EV 144. Depending for example on the time of the week, it may be that the EVs 144 may act both as consuming units and production units meaning that they may provide electricity stored to their batteries back to the grid if needed. Additionally, or alternatively, a consumption unit may further be associated with a storage, such as long-term storage of electricity. Such storage 145, which in this exemplary embodiment is associated with the household 135, may comprise a battery system that is capable of charging the batteries, such that electricity may be stored, for varying periods of time, from the grid 100 and / or from for example photovoltaic panels, which may be understood as solar panels, or wind turbines that are associated with the household 135. Thus, the storage 145 may charge itself when there is suitable electricity consumption and also produce electricity when needed by providing it to the household 135 and / or to the grid 100 for example.

[0022] In the grid 100 the consumption of electricity by the consumption units must be, in balance with the generated electricity by the power plants. In case there would be an imbalance, for example even slight imbalance, between generation and consumption of electricity in the grid, that could then lead to a significant blackout. In other words, the grid 100 is to have generation of electricity that matches the level of consumption in order to function properly and not to cause damage. For example, in case the frequency used in the grid 100 has nominal value of 50Hz, then the grid 100 may be considered to be in balance if fluctuation of the frequency is limited to for example between 49,9 and 50,1 Hz. Yet, it is to be noted that the nominal value of the frequency could be other than 50 Hz, for example, 60 Hz. Also, the allowed fluctuation of the grid may vary in different exemplary embodiments. Yet, the level of consumption varies over time and is not constant. Also, the power plants that are based on renewable energy may generate electricity with great variation and thus their generation is not constant.

[0023] In order to know how to balance the grid 100, the consumption of electricity may be predicted and then the production of electricity may be planned such that it meets the consumption need. This may be done for an upcoming time period such as for the next day, by basing the predictions on factors such as forecasted weather, time of the year and historical data regarding consumption of electricity. Various mathematical models may be utilized for such predictions that predict the fluctuation of consumption for example over longer periods of time, daily, hourly and / or seasonally.

[0024] Although the predictions may be rather accurate, the actual consumption at a given time may still vary from what was predicted. Additionally, the production may also vary from what was planned. Thus, the operator of the grid 100 is to have reserves available at all times so that the deviations from what was planned and predicted can be met and the production and consumption of electricity in the grid 100 is at balance at all times. For example, there may be peak load reserves that are activated to increase production and supplying of electricity to the grid 100 when consumption is greater than anticipated. Alternatively, or additionally, there may be reserves, which may be understood as reserve units, that are consumption units that adjust their consumption of electricity received using the grid 100 and / or production units that may provide electricity to the grid 100. When the reserve unit is capable of providing electricity to the grid 100, in other words, when it may act as a production unit, the electricity may be provided from its battery system that has stored electricity. The battery system may comprise for example a plurality of any suitable type of individual storages and / or an EV that can consume and / or provide electricity to the grid 100. Such reserve units, that may be used to balance consumption of electricity by either reducing or increasing its consumption of electricity, and / or produce electricity to the grid 100, and which are associated together as they are for example part of the same building, may be called a balancing unit. Such a balancing unit may then participate in one or more commercial markets that are for arranging the reserve for an upcoming time period, such as for the next day.

[0025] There may be various types of reserve markets for example, depending on the purpose of the reserve market. For example, there may be reserves for stabilizing the frequency within the grid 100, that are meant for continuous controlling that the frequency in the grid 100 remains stable. Such reserve market may be referred to as a frequency containment reserve (FCR) for example. The FCR may be for a normal operation (FCR-N) such that the reserve is constantly maintained for frequency regulation of the normal state of the grid. As another type of reserve, there may be an FCR for disturbances (FCR-D), which may be maintained to the extent that the steady state frequency deviation caused by any individual fault is not more than a pre-determined amount, for example, not more than 0.5 Hz.

[0026] In a grid, there is also inertia, which slows changes in frequency that are caused by changes in balance between production and consumption of energy. When production of energy or the consumption of energy changes, that may cause the frequency of the grid to change as well, but the inertia caused by kinetic energy in the grid slows the change. Yet, there may be situations of low inertia, which may be addressed using one type of a reserve dedicated for it. Such type of reserve may be referred to as a fast frequency reserve (FFR). As the low inertia situation may last only temporarily, this reserve may be procured for some hours and the amount of reserves may vary. For example, a dimensioning principle may be followed that indicates that a loss of an electricity production unit or a high voltage direct current (HVDC) link cannot cause the frequency to fall below a certain value, for example below 49.0 Hz.

[0027] As a further example, there may be reserves that are for restoring the frequency within the grid to its normal range, such as 49,9 - 50,1 Hz, and to release the activated resources for stabilizing back to usage. For example, an automatic frequency restoration reserve (aFRR) is to return the frequency of a grid to its nominal value, which may be for example 50 Hz or 60 Hz. The aFRR may be a centralized reserve that is activated automatically. It may activate based on an activation request signal sent by an operator of the grid. The activation request may be calculated based on the frequency deviation and may be sent periodically, for example, every 10 seconds. There may also be a reserve type that is for manual frequency restoration, and which may be referred to as manual frequency restoration reserve (mFRRj. This reserve may be activated to compensate the imbalances of balance responsible parties in terms of deviations. The activation time may be for example approximately 15 minutes.

[0028] The frequency of the grid 100 may have a nominal value such as 50 Hz. It is to be noted that the nominal value could alternatively be something else, for example, 60 Hz. The nominal value indicates a balanced state in which the consumption of electricity matches the production of electricity within the grid 100. In case the production of electricity becomes greater than the consumption, then the frequency within the grid 100 may increase, for example to 50,1 Hz. Correspondingly, in case the consumption of electricity within the grid 100 becomes greater than the production of electricity, then the frequency decreases for example to 49,9 Hz. It is to be noted that the frequency could fluctuate to higher and / or lower values as well, but it may be desirable to limit the fluctuation to a certain range, for example, to be between 49.9 Hz and 50.1 Hz. The variation of the frequency may then act as a triggering event for a balancing action that involves using the reserves available from the reserve markets to bring the grid 100 back to a balanced state by adjusting the consumption and / or production of the electricity. It is to be noted that depending on the amount of fluctuation from the nominal value, there may be limitations in terms of for how long the frequency of the grid may be allowed to deviate from the nominal value before a reserve is activated in order to balance the grid. For example, the greater the deviation from the nominal value, the sooner a reserve is to be activated, in other words, the sooner a trigger for a suitable balancing action is to be provided.

[0029] When a balancing action is to be performed, and the balancing action comprises adjusting consumption and / or production of electricity, then it is effective and convenient to adjust the consumption of one consumption unit that consumes a rather large amount of electricity. For example, an industrial building such as factory may adjust its consumption of electricity and that may have a significant impact on the balance of the grid. An individual household, which may also comprise energy storages such as battery systems, for example, may by itself be insignificant in terms of the balance of the whole grid. Yet, when summing up the consumption of many individual households, and / or office buildings etc., that receive their electricity using the grid, then their aggregated, in other words, combined, effect may be considerable and have an effect on the balance of the grid.

[0030] An individual household consumes a significant part of its electricity consumption for heating its domestic hot water and controlling the room temperature, which may be understood as temperature of the space of the building. It is to be noted that within the building the room temperature may vary in different parts of the building. The room temperature may be controlled by heating or by cooling the space. Yet, variation of room temperature by for example 1 or 2 degrees of Celsius may not be disturbing to people in the building. Furthermore, if the building is empty, the room temperature may be allowed to fluctuate even more. Also, the domestic hot water may be varied in terms of temperature without causing disturbance to people using the domestic hot water. For example, by varying the temperature of the domestic hot water by a few degrees of Celsius may be considered as being acceptable and not causing disturbance to the people using it.

[0031] Figure 2 illustrates a flow chart according to an exemplary embodiment in which the capacity of a domestic building is evaluated in terms of the building acting as a balancing unit in an aggregated group of domestic buildings, office buildings and / or other relatively small consumption and / or production units, in other words reserve units, acting as balancing units. In this exemplary embodiment, it is illustrated how the capacity of the aggregated group of balancing units, which in this exemplary embodiment are domestic buildings, such as houses, is estimated and aggregated for being available for an upcoming balancing time period such as for the next day or for the next hours. As the consumption of electricity is dependent on the weather, the weather forecast 200 may be taken as an input that is one of the bases for the estimation. The weather forecast 200 may be different for different buildings as the buildings may be located in different places and different places have different weather forecasts. Thus, the weather forecast 200 may be understood as multiple weather forecast such that one weather forecast is associated with one or more balancing units. The association may be indicated for example as a linkage between a weather forecast and balancing unit(s) and / or as a data field included in the data regarding the weather forecast and / or the balancing unit(s) associated with the weather forecast.

[0032] Additionally, the historical data 205 regarding each balancing unit may be analysed. The historical data 205 may comprise historical information of a balancing unit’s electricity storage(s), as well as heating and / or cooling system(s) and their capacity and / or heating storage of the building. By analysing the historical data 205 the operational limitations of the building may be estimated. The operational limitations may be understood as limitations for example in terms of storing, providing and consuming electricity in different conditions as well as limitations in terms of heating capacity of the building. The historical data 205 may then be utilized for example in making predictions regarding the electricity consumption and / or production of the balancing unit during the upcoming balancing time period as well as the potential flexibility in case the temperature of the room temperature and / or domestic hot water is varied. This may include taking into consideration the amount of variation that there is available before the comfort of people within the building is compromised. In other words, the consumption of electricity may be adjusted by adjusting the temperature of one or more reserve units within the building, the one or more reserve units comprising the heating or cooling system of the building and / or the domestic hot water. Additionally, or alternatively, the historical data may be used as a basis for predicting the availability of electricity that can be provided to the grid from one or more storages of the balancing unit, as well as the potential to consume more electricity by storing the electricity to the one or more storages of the building. It is to be noted that for a storage to be a storage of the building, the storage is to be associated with building, but not necessarily attached to the building. The association may be achieved for example by the building and the storage being part of the same connection to the grid. Any suitable software algorithms may be utilized when analysing the historical data 205. It is to be noted that also machine learning models may be trained to provide the analysis or at least part of the analysis. Thus, a thermal storage capacity of the balancing unit, as well as other electricity storage capacity of the balancing unit, that may be available for usage of a balancing action, may be considered as an outcome of the analysis.

[0033] The outcome may comprise coefficients that describe the main factors regarding the balancing unit’s capacity available for the reserve market during the upcoming balancing time period. The coefficients may thus be for example coefficients describing balancing unit’s past temperatures, the expected weather outside that is based on the weather forecast associated with the balancing unit, and heating power of the space heating system and / or the heating power of the water heating system. The coefficients may be obtained using a fitting model to the historical data of a building. The coefficients thus reflect the building’s thermal capacity which may be used as a reserve capacity when aggregated with that of other buildings. The capacity may thus be estimated based on analysing past temperature data associated with the building together with the operating power of the heating / cooling and / or domestic hot water systems. Additionally, or alternatively, there may be coefficients that describe the buildings capability to consume electricity by storing it to a storage, such as an EV and / or a battery system, and / or the capability of the storage system to produce electricity to the grid.

[0034] The analysing may be performed in any suitable unit, for example, in a computing unit comprising at least one computing device connected to the balancing unit, and / or in a remote service comprising at least one computing device and the remote service being configured to connect to the balancing unit and to provide instructions regarding controlling the heating of the space and / or water in the balancing unit.

[0035] Then based on the weather forecast^] and the analyses of the individual balancing units a mathematical model 210 may be built for each balancing unit. Building the mathematical model may be performed using any suitable algorithms. Additionally, or alternatively, trained machine learning models may be used to build the model which then determines the availability of capacity each balancing unit has for reserve purposes during the upcoming balancing time period. The mathematical model may also utilize simulations available for simulating consumption of electricity in the balancing unit.

[0036] One example of a mathematical model that may be used to define a balancing unit, such as a building, is to determine the behaviour of the balancing unit in terms of how it may act as a power consumer or provider with respect to the grid. This allows to define the balancing unit as if it was a battery that is connected to the grid, and which may adjust the consumption and / or production of electricity towards the grid. There may thus be a state of the charge [SOC] curve defined for the balancing unit based on for example the specifications of the balancing unit, and thereby the balancing unit may be defined using the SOC curve defined for it. The SOC curve may then define the balancing unit, such as a building, on similar terms as batteries in general. This enables the building for example to be considered as a building as a battery [BaaB], and the SOC curve may be used to indicate, regarding the balancing unit, for example power changes rate and amount of available flexible power with respect to the total power flexibility potential the balancing unit may provide. Thus, the balancing unit, such as a building, or any other suitable balancing unit, may be defined, at least partly, using a SOC curve, alike to how an SOC curve may be utilized for optimizing the use of stored electricity in electric vehicles, renewable energy systems with storage, and / or grid-scale energy storage for example. For example, in case the building uses power to heat (P2H) operations for providing flexibility that allows a balancing action to be performed by the building, the P2H functionality may be modelled using the SOC curve for example.

[0037] When performing the evaluation for the upcoming balancing time period, also forecasts of availability of resource 215 overall for the grid may be taken into account. Such forecasts may be based on, at least partly, on SOC curves defined for the balancing unites]. This allows to estimate for example in which type of reserve there is the greatest potential for flexibility. Thus, it may be determined in which type of reserve market the available capacity would be best in use. Trained machine learning models, such as deep learning models, may be utilized for forecasting the resources available 215 overall in various reserve markets.

[0038] The mathematical models 210 and the availability of resources 215, which may be at least partly determined based on mathematical models such as SOC curves, may be taken as input based on which an optimization model 220 is built. The optimization model 220 then further analyses the restrictions of individual balancing units and determines a total objective function that is utilized to determine the energy markets for which an aggregated set of balancing units is provided to the upcoming balancing time period. It is to be noted that a plurality of aggregated balancing units may be determined, and different aggregated balancing units may participate in different reserve markets during the upcoming balancing time period. It is also to be noted that the optimization model may have as an integrated feature the prequalification constrains that have been determined for each reserve market. This may also be considered when determining the reserve market for each aggregation. Optionally, depending on the reserve units comprised in one balancing unit, the balancing unit may be such that it is determined that it can be part of different types of balancing services provided.

[0039] In the optimization model 220 the threshold values for room temperature 222 of individual balancing units may be taken into account such that it is ensured that the temperature fluctuates between the threshold values. The temperature values may fluctuate differently depending on if there are expected to be people within the building during the upcoming balancing time period for example. The threshold values may be determined automatically, based on pre-determined settings or they may be received as an input from a user for example.

[0040] Correspondingly, the threshold values for water temperature 224 of individual balancing units may be taken into account such that the temperature of the water fluctuates between threshold values that may be pre-determined, automatically determined, or received as an input. The temperature of the water may be allowed to fluctuate differently during different time periods.

[0041] The optimization model 220 may be determined using one or more computing devices in any suitable unit, such as in a service configured to connect to and control a plurality of balancing units and / or to be connected to at least one grid operator.

[0042] As its outcome, the optimization model 220 may provide a total aggregated capacity 230 for a reserve market, that comprises a plurality of balancing units aggregated using the optimization model 220. Additionally, the optimization model 220 may provide information regarding aggregated offerings comprising a plurality of balancing units for each different reserve markets for the upcoming balancing time period.

[0043] The optimization model 220 may further be configured to determine prioritization for different balancing units such that in case flexibility offered is needed, there is a priority which balancing unit is to adjust its consumption and / or production of electricity first, which one then and so on. The flexibility offering is to have safeguarding margins such that they are able to meet the promised offering and thus there may be a situation in which the need for flexibility is less than the total flexibility available. Thus, the prioritization guides how to react in case there is a need to react. A benefit associated with the aggregation of balancing units is that a balancing unit that by itself would not be significant enough to participate in the reserve markets may this way still be allowed to offer its capacity to the reserve market.

[0044] Figure 3A illustrates an exemplary embodiment in which the frequency of a grid is a trigger for performing a balancing action in an aggregation of balancing units. In this exemplary embodiment, there is a grid 300 for distributing produced electricity consuming units. The grid 300 may be alike to the grid 100 discussed previously. In addition, there are aggregated balancing units. In this exemplary embodiment there are three different groups of aggregated balancing units, in other words three aggregations, 330, 340, 350. The aggregation 330 comprises building that can be used as offices and / or for other business purposes. The aggregation 340 comprises a combination of office buildings and households. The aggregation 350 comprises individual households. It is to be noted that there could be another number of aggregations as well and the aggregations could have different kinds of combinations of balancing units. Also, the aggregations may also comprise storage(s) for electricity that may be used for adjusting consumption and / or productions of electricity. It is also to be noted that different aggregations may participate in different reserve markets. It is further to be noted that the geographical location of balancing units within one aggregation may be limited to certain geographical areas or the aggregation may comprise balancing units from various different geographical locations.

[0045] As the frequency 310 of the grid 300 then fluctuates, that may be determined to be a trigger for the aggregations 330, 340 and 350 to perform their respective balancing actions. The trigger may be determined using a controlling unit 320 that may be for example a remote service that is connected to the grid 300 and to the balancing units of the aggregations 330, 340, and 350. The controlling unit 320 may comprise at least one computing device configured to execute software algorithms comprised in computing instructions of a computer program that is stored and executed by the at least one computing device. The controlling unit 320 may be, at least partly comprised in cloud computing service. Alternatively, or additionally, each aggregation 330, 340 and 350 may be controlled by its dedicated controlling unit 320 that is connected to the balancing units comprised in the aggregation and to a central controlling unit that may be connected to the grid 300 for example. It is to be noted that any other suitable implementation for the controlling unit 320 may also be used.

[0046] The controlling unit 320 then determines the balancing action that may comprise adjusting consumption and / or production of electricity by reserve elements 325 of at least some of the balancing units comprised in at least one of the aggregations 330, 340 and 350. The reserve elements may comprise for example heating of the space of a balancing unit, heating of water or controlling the heating, ventilation, and air-conditioning [HVAC] properties of a balancing unit. In case the frequency drops from the nominal value of the grid 300, then the balancing action may be determined to be reducing the heating and thus reducing the consumption in the grid. The amount of reducing done is dependent on the amount of adjusting required to the consumption. Alternatively, or additionally, the reserve elements 325 may also comprise one or more EVs and / or one or more storage for electricity such as battery system(s). In case the frequency of the grid drops from the nominal value, the energy consumption of these elements may be reduced and / or they may be activated to provide electricity they have stored to the grid. The activation may comprise for example causing the one or more EVs to discharge the battery systems. Optionally, there may be a pre-determined limit for at least some of the EVs below which they do not discharge their battery systems however. Correspondingly, in case the frequency in the grid increases from the nominal value, then the consumption of electricity by these elements may also be increased. For example, the one or more EVs may be caused to charge their battery systems.

[0047] The determining of the balancing action then comprises taking into account the priorities and capabilities of each balancing unit within an aggregation 330, 340 and 350 to determine how an individual balancing unit is instructed to react and / or if there are balancing units that do not need to adjust their consumption by performing a balancing action. When determining the balancing action, the SOC curves of individual balancing units may be considered. This may be beneficial as then the balancing units, that may be very different types of units, may be treated using the same manner of identifying the flexibilities available for the balancing action from each of the balancing units. In other words, the same terminology and specifications may be used for various types of balancing units. Thus, the aggregation may be formed while being agnostic to the types of balancing units as it is not required to know if a balancing unit is a building or an electrical battery for example. Both can be defined in using same terminology and specifications. For example, in case the aggregation is formed by an energy management system (EMS), the EMS may not differentiate between the types of balancing units but may form an aggregation based on the SOC curves of individual balancing units for example.

[0048] Correspondingly, in case the frequency 310 goes above the nominal value of the grid 300, then the balancing action may be determined to be increasing consumption by instructing at least one balancing unit in at least one aggregation 330, 340, or 350 to increase its consumption by increasing heating of space, or increasing air conditioning, and / or increasing heating of water. The amount of adjusting required as well as the priorities determined for the balancing units within an aggregation 330, 340 and 350 may determine which balancing units are instructed the adjust their consumption of electricity. The instructing may be performed using any suitable means to connect to a controlling unit of the balancing unit, the controlling unit being configured to adjust, at least partly automatically, the consumption of electricity of the reserve units comprised in the balancing unit.

[0049] In case there are storages as reserve units that are used for performing a balancing action, the balancing action may comprise producing electricity, in other words, providing electricity from the storage to the grid, when the frequency decreases below its nominal value. Correspondingly, the storage may consume more electricity, for example charge its battery system, in case the balancing action requires increasing consumption as the frequency goes above the nominal value of the grid. The increased consumption may also comprise charging an EV, or charging the EV at higher power for example.

[0050] In this exemplary embodiment, the trigger condition of the power grid 300, which is also the trigger for the balancing action, may be determined by measuring the frequency. The measuring may be performed in any suitable manner. For example, the measuring may be centralized frequency measuring, or it may be local frequency measuring.

[0051] If the measuring is centralized frequency measuring, then the frequency is measured from the transmission grid. The measurement may then be communicated to the controlling unit 320 and the control unit may determine the suitable balancing action. This approach may be useful in case there are reliable and redundant frequency measurements available as well as reliable low- latency communication.

[0052] In case of local frequency measurements, the frequency may be measured locally. This may be used for example as a back-up for the centralized frequency measurement, or if the balancing of the grid is performed in a local manner using local aggregations of balancing units. This approach may also be used in case fast low-latency communication is not available. In this option, the frequency may be measured at a connection point of a balancing unit or an aggregation of balancing units. Then, there may be available locally stored predefined settings regarding what the balancing action should be for each locally determined trigger condition. This is beneficial for example if the reliable fast communication to the control unit 320 for example is not available. The predefined settings however may have been obtained from the controlling unit 320 and / or they may be updated by the controlling unit 320. Using the local frequency measurement, balancing operations may be used even if the fast and reliable communication to the controlling unit 320 would not be available. By having the central and the local frequency measurement options, the balancing actions may be executed as the frequency measurements may be obtained continuously even if the conditions for fast communication vary.

[0053] One example of balancing a grid in a distributed manner may be such that there are local areas, which may also be referred to as zonal areas, and a control system for one zonal area may determine an aggregation of balancing units within the zone for an upcoming balancing period for example. In such an example, the grid may be operated using a central operator, which may be referred to as a transmission system operator (TSO), and one or more distribution system operators (DSOs). The TSO may be responsible for controlling and operating the transmission grid and transport electricity to the local areas. A DSO may then operate and manage the local electricity distribution network. It is to be noted that there may be a plurality of zonal areas per one DSO, the zonal areas together forming the local area in which the DSO controls the electricity distribution network. Alternatively, the local area may correspond to one zonal area.

[0054] Figure 3B illustrates an exemplary embodiment in which there is at least one zone, having a control system for the zone and the zone provides services to a DSO. For the ease of explanation, one zone is discussed, but there could be a plurality of zones with their respective control systems providing services to the DSO. In this exemplary embodiment, the utilization of zonal clustering is explained using two illustrations, the illustration 360 and the illustration 365. In other words, the utilization may be illustrated with alternative illustrations. Therefore, the elements in the illustrations 360 and 365 are referred to with the same reference numbers. It is also to be noted that in some exemplary embodiments, the control system may be at least partly comprised in the DSO.

[0055] In this exemplary embodiment, the frequency of a grid is measured in the zonal area, in other words, the frequency that may be a trigger for a balancing action is obtained with respect to a zonal area that may be referred to as a local area. Obtaining of the frequency of the zonal area may be performed by the control system for example. For the purposes of being able to perform the balancing action, a zonal cluster is to be determined. Therefore, the control system determines available balancing units 370 for participating in a balancing action during an upcoming balancing time period. The available balancing units may also be referred to as distributed resources.

[0056] As the available balancing units 370 are known to the control system, the control system may then follow parameters referred to as flexibility parameters 380, such as rates of electricity prices and frequency of the grid. It is to be that there may be other flexibility parameters to follow as well. As the flexibility parameters indicate that a balancing action is to be performed, the control system may form a cluster of suitable balancing units to perform the balancing action. The SOC curves of the balancing units may for example be used as a basis for determining the suitable aggregation that may then perform the balancing action that may also be referred to as a flexibility response 390, or a partitioning approach. The flexibility response 390 may thus aggregate zonal aggregations to participate in one reserve market, or alternatively, may assign aggregations to a plurality of reserve markets.

[0057] It is to be noted that although not illustrated, each unit 370, 380 and 390, may exchange signalling with the DSO as well as TSO, as the balancing units are participating in at least one reserve market. As the TSO then needs balancing, the balancing operations available locally and provided as services for the DSO may be used to balance the grid in a local, and therefore distributed manner. Having the flexibility parameters 380 enables the DSO to have an effective and enhanced communication with the TSO, and thereby local energy communities may provide balancing services to the TSO. Also, the formation and management of flexibility response enables optimizing DSO-TSO interaction. With the approach discussed in this exemplary embodiment, a solution for integrated energy markets may be achieved when there are a lot of different flexible energy resources connected to the energy system resulting in a more decentralized energy system.

[0058] Figure 4 illustrates a flow chart according to an exemplary embodiment in which the balancing action(s) are determined during the balancing time period for which the aggregations were determined as described in the context of the previous exemplary embodiments. In the flow chart illustrated in figure 4, in the step 410 the estimation of capacity of individual balancing units available for the balancing time period is received as input. Then at least one aggregation, that comprises a group of balancing units, is determined and the at least one aggregation is formed. The at least one aggregation is selected such that a required capacity is available for a chosen reserve market. The required capacity may be capacity that has been promised to the chosen reserve market. It is to be noted that for the chosen reserve market, there may be also other aggregations providing capacity in addition to the determined at least one aggregation. Additionally, or alternatively, there may be at least one aggregation among the determined at least one aggregation that provides capacity at least one other reserve market in addition to the chosen reserve market.

[0059] In step 460, a controlling unit then observes a trigger in the grid. The trigger may be a deviation of the frequency from the nominal value of the grid as discussed in previous exemplary embodiments. Alternatively, there may be an indication received that is determined to be the trigger. Then, for the at least one aggregation, balancing action(s) are performed. In this exemplary embodiment, step 440 comprises performing a balancing action with respect to heating of space in individual balancing unites] comprised in the at least one aggregation. The balancing action comprises selecting the balancing unit with the highest priority in terms of it being the first one to react to achieve the required balancing. For the selected balancing unit, it is determined if the temperature of its space is within threshold values, in other words, within a pre-determined range as illustrated in step 450. If yes, then the flowchart returns to step 440 and performs adjusting of the space heating of that balancing unit again. If no, then the flow chart proceeds to step 460 and determines the next balancing unit for which to perform balancing action(s). The next one may be determined based on its priority in the prioritized order of the balancing units.

[0060] Additionally, or alternatively, adjusting of the temperature of the water for the balancing unit with the highest priority may be performed as illustrated in the step 445. Then, in step 455 it is determined if the temperature of the water is within a pre-determined range. If yes, the flow chart then proceeds back to step 445. If not, then the flow chart proceeds to step 460 and selects the next balancing unit for which a balancing action is determined.

[0061] The flow chart may be performed automatically, in other words, the flow chart may be performed by a computer-implemented method, that is performed using at least one computing device. The at least one computing device may then be connected to individual balancing units such that it can transmit instructions according to the balancing action determined for the balancing unit. Also, the at least one computing unit, that may be comprised in a monitoring unit may also receive information from an individual balancing unit such that it is aware of the temperature of the space and / or the water in the balancing unit. It is to be noted that although the temperature of the space and the water in the balancing unit are discussed herein, there may also be other electricity consuming entities in a balancing unit that may correspondingly be used to performing balancing actions.

[0062] It is to be noted that although the flow chart in this exemplary embodiment comprises a balancing action that is performed with respect to temperature, such as heating a space and / or temperature of water, in some other exemplary embodiments the balancing action may additionally, or alternatively, be performed with respect to storage of electricity, or a thermal storage. For example, consumption and / or production may be adjusted by storing electricity to a storage such as long-term storage comprising a battery system, and / or an EV, and / or a thermal storage.

[0063] Figure 5 illustrates an exemplary embodiment of a computing device 500, which may be or may be comprised in a monitoring unit such as those described above. In this exemplary embodiment, there is at least one processor 540, at least one memory 530, at least one connectivity unit 510 and at least one unit for receiving input and providing output 520. It is to be noted that the units described here are logical units and thus the actual implementation may vary. The at least one processor 540, at least one memory 530, at least one connectivity unit 510 and at least one unit for receiving input and providing output 520, such as visual or audio output, may be connected to each other.

[0064] The at least one processor 540 may also be referred to as core, a central processing unit (CPU), microprocessor or graphical processing unit (GPU). A processor may be understood as an integrated circuit for performing calculations according to instructions provided using computer code. The at least one memory 530 may comprise volatile and / or non-volatile memory. Thus, the at least one memory 530 may be understood to be one block of memory or a combination of different blocks of memory. The memory may be for storing different types of data. The at least one memory 530 stores also computer program instructions, for example in the form of an application and / or an operating system. The at least one memory 530 provides computer program instructions to the at least one processor 540 for executing and the at least one processor 540 may then be configured to store data into the at least one memory 530. Some examples of memory are random access memories (RAMs), such as static RAM (SRAM) and dynamic RAM (DRAM), read-only memory (ROM), flash memories, optical discs, and magnetic computer storage devices, such as hard disk drives. The input and output unit 520 may allow user input, such as pressing a button, touch input and / or voice input, to be received by the device 500 and output such as audio, haptic or visual output to be provided to a user. The connectivity unit 510 allows connection to be formed between the device 500 and another device. The connectivity unit may allow wireless and / or wired connections to be formed between the device 500 and other devices. Examples of connection types that may be supported by the connectivity unit 810 are cellular communication -based connections, local area networks, Bluetoothconnections, Wi-Fi connections, etc.

[0065] The present disclosure has been described above with reference to the exemplary embodiments. However, a person skilled in the art will understand there may be embodiments that vary from the example embodiments discussed above within the scope of the claims. Thus, skilled person will understand that the exemplary embodiments described above may, but are not required to, be combined with each other and / or other exemplary embodiments in various manners.

[0066] The exemplary embodiments described above enable consumers, for example households, to have a more active role in the electricity market. The consumers, who are often considered as end-users in the energy markets, may be considered as end-users in different generations. Thus, some generations of energy end-users have been born during the years that the energy advancements are happening. It may be considered that first, there was a generation who were sole consumers for a long time. This generation is used to consuming without even knowing how the energy is provided or reached to them. The second generation was born when more access to renewables was given to energy endusers. They may be referred to as prosumers. The prosumers are aware of their role in producing and consuming onsite. The energy production and consumption chain are more important to them, and they see themselves as having an active role in their own energy management as a prosumer. Now due to the latest advancements of energy and the importance of energy democracy promotion and responsible consumption, the third generation is being born, and they may be referred to as flexumers. The flexumers are taking one step further and are playing a role in the energy market actively as providers of flexibility. This increases the role of energy end-users to engage the energy market in a positive way. The exemplary embodiments described above have a benefit of enabling more energy end-users to become flexumers.

Claims

CLAIMS1. A method for balancing a grid, the method comprising: determining an aggregation that comprises a group of individual balancing units, wherein each balancing unit defined by a state of charge curve defined for it, and each balancing unit provides capacity for a reserve market, and wherein the capacity comprises ability to adjust consumption and / or production of electricity of at least one reserve unit comprised in the individual balancing unit; observing a trigger, wherein the trigger indicates a need to balance the grid; determining, based on the trigger, a balancing action for the aggregation; and performing the balancing action within the aggregation.

2. A method according to claim 1, wherein adjusting the electricity consumption and / or production of the at least one reserve unit comprises at least one of the following: providing electricity from at least one electricity storage, that is comprised in the reserve unit, to the grid; adjusting consumption of electricity of the at least one electricity storage; and / or adjusting temperature of the at least one reserve unit, wherein the temperature is adjusted within pre-determined threshold values.

3. A method according to claim 2, wherein the at least one reserve unit comprises one or more of the following: an electric vehicle (EV); the at least one electricity storage; a heating, ventilation and / or air-conditioning unit; a thermal storage; a heat storage; and / or domestic hot water.

4. A method according to any of claims 1 to 3, wherein the balancing action comprises adjusting the electricity consumption and / or production of one or more individual balancing units within the aggregation based on the priority of each individual balancing unit of the one or more balancing units.

5. A method according to any previous claim, wherein the trigger comprises frequency of the grid deviating from its nominal value, and / orreceiving an indication indicating a need for a balancing action; and wherein the method further comprises measuring the frequency of the grid in a centralized manner or in a local manner.

6. A method according to claim 5, wherein the deviation of frequency that increases from the nominal value indicates that the balancing action is to increase consumption of electricity and / or decrease production of electricity, and the deviation of frequency that decreases from the nominal value indicates that the balancing action is to reduce the consumption of electricity and / or increase the production of electricity.

7. A method according to any previous claim, wherein the aggregation is determined based on determined reserve capacity provided by each balancing units and the aggregation is determined and formed for a balancing time period.

8. A method according to claim 7, wherein the reserve capacity is determined for each of the balancing units based on analysis of historical data of each of the balancing units, operational constraints of each of the balancing units, and a weather forecast associated with each of the balancing units for the balancing time period.

9. A method according to claim 7 or 8, wherein the aggregation is further determined based on a reserve market for which the reserve capacity of each of the balancing units is provided for during the balancing time period.

10. A method according to claim 9, wherein the reserve market is selected based on a prediction of overall availability of reserve capacity for the reserve market.

11. A method according to claim 10, wherein the prediction is obtained using a trained machine learning model.

12. A method according to any previous claim, wherein the balancing action comprises providing an instruction to at least one balancing unit comprised in the aggregation, the instruction comprising information on how to adjust consumption and / or production of electricity in the balancing unit.

13. A method according to any previous claim, wherein the method comprises determining a plurality of aggregations and at least two of the plurality of aggregations provide reserve capacity for different reserve markets.

14. A control unit for balancing a grid, the control unit comprising at least one computing device; means for creating and coordinating an aggregation of a plurality of balancing units, wherein the aggregation is for providing a reserve for balancing actions required by a grid; means for establishing and having a connection to one or more balancing units comprised in the aggregation, wherein the balancing units are configured to provide reserve capacity that can be activated as a response to a balancing action; means for receiving a trigger, wherein the trigger indicates a deviation of a frequency of the grid from its nominal value and / or a need for the balancing action; and means for performing a method according to any of claims 1 to 13.

15. A computer program product comprising instructions, which, when executed by a computing device, cause the computing device to perform a method according to any of claims 1 to 13.

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