Improvements to systems utilising environmental energy

Abstract

A hybrid system suitable for generating electricity from solar irradiance and transferring energy from the environment to an energy storage system, the system comprising: a thermodynamic panel comprising a refrigerant, the panel being configured to vaporise the refrigerant using heat extracted from the environment; a photovoltaic film overlaid on the thermodynamic panel; a heat pump for compressing refrigerant vapour from the panel into hot refrigerant vapour, a condenser for transferring heat from the hot refrigerant vapour to an energy storage system; and a controller configured to manage the refrigerant flow from the heat pump either to the condenser or back to the panel.

Description

[0001] IMPROVEMENTS TO SYSTEMS UTILISING ENVIRONMENTAL ENERGY

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the field of systems utilising environmental energy, and in particular, to a hybrid system suitable for generating electricity from solar irradiance and transferring energy from the environment into an energy storage system.

[0004] BACKGROUND TO THE INVENTION

[0005] Thermodynamic solar heat transfer systems are designed to transfer external environmental energy into heat energy which can be used in internal environments such as buildings, including domestic dwellings. Such systems transfer the external environmental energy to a heat transfer liquid, which is typically water. The heated water runs to a heat exchanger inside a building's water tank, where the heat from the exchanger warms the water stored in the tank. The heated water from the tank can either supply a radiative heating system or may be a domestic hot water (DHW) supply to kitchens and bathrooms and so on. Such a system is distinct from 'air source' heat exchange systems which typically utilise fans to blow air across evaporator and / or condenser parts of the system and run air conditioning / heating units within buildings.

[0006] Some thermodynamic solar heat transfer systems utilise refrigerant as a heat transfer fluid, which enables significantly greater efficiencies compared to systems utilising water as a heat transfer liquid. Refrigerant based systems typically comprise at least one aluminium panel and a heat pump. Typically, a refrigerant fluid is entered to the panel as a liquid down to -20°C. The panel is outside, and absorbs energy from the environment which is used to convert the refrigerant liquid into a vapour. This vapour then passes into the heat pump, where it is compressed, raising the temperature of the vapour to approximately 80°C. The hot refrigerant vapour is entered into a heat exchanger or condenser, where the hot refrigerant vapour imparts its heat into water. The water temperature in the tanks is raised to a predetermined temperature. The heated water is then used within a building as a supply to heating elements such as radiators, underfloor heating systems, or swimming pool heaters, and / or as a DHW supply to kitchens, bathrooms and the like. The cooled refrigerant then passes into an expansion valve before the cycle repeats. This system is in common usage in some southern European countries and has also been used in some northern European countries.

[0007] The combination of thermodynamic solar heat transfer systems and solar photovoltaic (PV) systems is known in the art as a hybrid solar system or a solar photovoltaic-thermal (PVT) system. In addition to transferring energy from the external environment to provide a supply of heated water, such systems also utilise sunlight to produce a supply of electricity. By combining solar photovoltaic and thermodynamic panels into a single unit, the amount of energy produced per square meter can be significantly increased in certain conditions. This is particularly advantageous when the panels are installed on rooftops where space is limited, and which may not otherwise be able to accommodate separate solar photovoltaic panels and thermodynamic panels.

[0008] PVT panels have a number of challenges including the weight and thickness of the combined panel, as well as poor thermal transfer between the photovoltaic and thermal panel elements. The performance of PVT panels is also dependent on the climate in which they are operated. In hotter external environments, the water circulating in the thermodynamic panel can have a cooling effect on the attached PV system, which can increase the efficiency of the hybrid system in hotter environments, below a temperature of approximately 25°C. When the external environment is above approximately 25°C, PVT panels are known to suffer from overheating, which significantly reduces the efficiency of the PV system. In cooler external environments, PVT panels are known to suffer from frosting / icing.

[0009] Frosting or icing occurs when the ambient outside temperature is low, and there is significant water vapour in the atmosphere. The atmospheric water vapour can freeze on the surface of the panels as frost or ice. This results in a problem of loss of efficiency as the ice on the surface impedes both the photovoltaic element from generating electricity, as well as energy transfer into the panel. This is exacerbated where the ambient outside conditions include precipitation of one form or another, such as snow or rain. There is a further issue of a potential safety risk as ice can build up into a significant layer over time. When the formed ice eventually thaws, it can slip from the panel. As such panels are often mounted on roofs or otherwise raised from the ground, this is a potential hazard to people or animals that might be standing beneath them or risk of damage to other objects beneath them. The formation of ice or accumulation of snow upon PVT panels is further undesirable due to the negative impact of these coverings would have on the optical transmission properties of any antireflection coating or nanotexture applied to the upper surface of the photovoltaic panel.

[0010] A known solution to prevent the build-up of ice on thermodynamic panels, is to provide the thermodynamic system with a temperature and / or humidity sensor and a controller which is configured to divert the flow of fluid from the heat pump back into the panel, when the ambient conditions measured by the temperature sensor and / or humidity sensor are cold enough or include sufficient air moisture for frost to form on the panel. There is therefore a requirement for an improved hybrid system which can be operated in a wide range of conditions and climates, without losing efficiency. The improved system should overcome the known challenges with PVT systems, including minimising thermal gradients between the photovoltaic and thermal panel elements, and provide a system with an improved geometry and lower weight, such that it is suitable for installation in a wider number of environments.

[0011] It is against this background that the present invention has arisen.

[0012] SUMMARY OF THE INVENTION

[0013] According to the present invention, there is provided a hybrid system suitable for generating electricity from solar irradiance and transferring energy from the environment to an energy storage system, the system comprising: a thermodynamic panel containing a refrigerant, the panel being configured to vaporise the refrigerant using heat extracted from the environment; a photovoltaic film overlaid on the thermodynamic panel; a heat pump for compressing refrigerant vapour from the panel into hot refrigerant vapour, a condenser for transferring heat from the hot refrigerant vapour to an energy storage system; and a controller configured to manage the refrigerant flow from the heat pump either to the condenser or back to the panel.

[0014] The present invention relates to a hybrid system which achieves a synergistic effect between the solar photovoltaic and thermodynamic panel elements to generate electricity and stored energy with an increased efficiency compared to both known PVT and individual PV and solar thermal systems.

[0015] In some embodiments, the hybrid system of the present invention transfers energy from the environment to an energy storage system. In some embodiments, the energy storage system may comprise a water tank. In some embodiments, the present invention may transfer energy from the environment to a tank of water, such that a domestic hot water supply can be obtained.

[0016] In some embodiments, the energy storage system may comprise at least one thermal battery. In some embodiments, the hybrid system may transfer energy from the environment into a thermal battery, where it may be temporarily stored until needed.

[0017] Within the context of the present invention, the term "environment" should be understood to include anywhere the system is installed. In some embodiments, the system may be installed on a rooftop, in a garden, or on an external wall. In some embodiments, the system may be installed inside and the photovoltaic film may receive solar energy through one or more windows. It should be noted that references to buildings, houses and / or dwellings are not intended to be limiting. It will readily be appreciated that various structures or collections of structures could have such systems installed thereon and that the components of such systems may sit on or within a variety of locations. Panels and sensors may be mounted on the outside of a building or on a pole or other structure next to a building. Various components of the system, for example the thermodynamic panel and / or the evaporator, may be open to the elements or be provided in adjacent enclosures, such as wooden huts next to a building or may be located within the building on which the panels are mounted. Buildings may include offices, hotels, restaurants or public buildings such as museums, town halls or sports centres, as well as houses or similar dwellings. The improved efficiency of the hybrid system further reduces the CO2 emissions of the buildings on which they are installed.

[0018] In some embodiments, the PV film of the present invention produces electrical power which can be used to drive the heat pump for compressing the refrigerant vapour. In some embodiments, the system may further comprise a water circulating pump, and the PV film may produce electrical power to drive the water circulating pump.

[0019] In some embodiments, the PV film produces electrical power, providing that there is sufficient solar irradiance to do so. In some embodiments, the electrical power generated by the hybrid system may be used to drive a pump which circulates the refrigerant around the thermodynamic panel. In some embodiments, excess electrical power generated by the PV film can be used to power the building on which the system is installed, can be fed to the grid, and / or can be used to charge batteries.

[0020] In some embodiments, the hybrid system may operate continuously. In some embodiments, the hybrid system may operate intermittently. In some embodiments, there may be periods in which the hybrid system generates electricity only, and the thermodynamic panel elements do not transfer any energy from the environment. In some embodiments, the thermodynamic panel may become operational in response to a certain trigger. For example, the hybrid system may sense that the external environment has dropped below a certain temperature which may trigger the operation of the thermodynamic panel.

[0021] In some embodiments, the hybrid system may be used to generate a supply of domestic hot water. In some embodiments, the hybrid system may operate until a tank of water is heated to a certain temperature, and then the hybrid system may stop heating the water. In some embodiments, the hybrid system may sense when the hot water in the tank drops below a pre-set temperature, which may trigger the system to start heating the water within the hot water tank again. Therefore, in addition to the temperature sensor configured to measure the temperature of the environment external to the panel, in some embodiments, the hybrid system may comprise one or more additional temperature sensors which may measure the temperature within the water tank.

[0022] In some embodiments, the hybrid system utilising a refrigerant based thermodynamic panel enables the system to achieve greater efficiencies than water-based heat transfer systems. In some embodiments, the controller may be configured dynamically to control the flow of refrigerant from the heat pump such that it either flows to the condenser or back to the thermodynamic panel. In some embodiments, the controller may be configured to control the flow of refrigerant to optimise the performance of the system depending on the weather / climate in which the hybrid system is being operated.

[0023] In some embodiments, the hybrid system may have a 'normal' operating condition, in which the controller is configured to flow refrigerant from the heat pump to the condenser.

[0024] In some embodiments, the controller may be configured to provide a 'defrost function' in which the controller flows hot refrigerant gas from the heat pump, back to the panel.

[0025] In some embodiments, when the temperature of the environment is sufficiently low, the controller may be triggered to divert the flow of hot refrigerant vapour back to the panel such that the temperature of the panel increases. In some embodiments, the diversion of hot refrigerant vapour into the panel acts as a hot gas defrost cycle. In some embodiments, any frost that has built up on the panel due to environmental conditions can be melted away, or any ice that has built up on the panel can be loosened for controlled removal. It has been found that, in wintry conditions, a 2 to 3 minute reversal of hot gas every few hours is sufficient to keep panels substantially frost-free. This is an important feature for ensuring the panels and the PV film are always clear of frost, ice and / or snow in cooler environments. This ensures the efficiency of the hybrid system is maintained year round, and the system is suitable for operation in cooler climates.

[0026] In some embodiments, the controller is configured to control the flow of hot refrigerant vapour back to the panel such that the panels are kept frost-free whilst minimising the impact of the hot gas defrost cycle on the efficiency of the PV film and overall system. In some embodiments, the controller is configured to keep any hot gas defrost cycle short in time interval and frequency. In some embodiments, the controller may further comprise a timer. In some embodiments, the system may further comprise: an expansion valve through which, in use, cooled refrigerant vapour from the condenser passes before being supplied back into the panel; a fluid control valve configured to enable refrigerant fluid from the panel to pass through the fluid control valve into the heat pump and then back through the fluid control valve into the condenser; and a temperature sensor and / or a humidity sensor configured to measure the temperature and / or humidity of the environment. The controller may be configured to monitor the temperature and / or humidity sensor and to act on the fluid control valve in order to divert hot refrigerant vapour back into the panel when the temperature and / or humidity sensors indicate fall below a threshold value indicative of frost or ice forming on the panel.

[0027] In some embodiments, the temperature sensor may be configured to measure the ambient temperature conditions to which the panel is subject. In some embodiments, this ensures the controller initiates the hot gas defrost cycle, only when the ambient conditions require it.

[0028] In some embodiments, the humidity sensor measures the ambient humidity to which the panel is subject. In some embodiments, this ensures the controller initiates the hot gas defrost cycle, only when the ambient conditions to which the panel is subject include sufficient air moisture for frost or ice to form.

[0029] In some embodiments, the humidity sensor may operate in combination with the temperature sensor. In some embodiments, the hot gas defrost cycle may only be initiated when the combination of temperature and humidity are such that there is a likelihood of frost or ice forming on the panel or panels. In some embodiments, the hot gas defrost cycle may be automated. In some embodiments, the controller may comprise a computing or other control device such as an Electronic Control Unit (ECU) which monitors the readings of the temperature sensor and / or humidity sensor, and regulates the time and frequency of use of the hot gas defrost cycle in response to these outputs so as to maximise the efficiency of the system, whilst still maintaining the desirable effects of the hot gas defrost cycle.

[0030] In some embodiments, by way of example only, the controller may be configured such that if the temperature of the environment is sensed to drop below 5°C, the defrost function runs for two minutes every six hours. In some embodiments, the controller may be configured to keep the hybrid system free from frost / ice by operating the hot gas defrost cycle for only eight minutes per day. In some embodiments, the controller may be connected via telecommunication link to a remote weather station or weather forecasting service. Information regards prevailing and predicted snowfall levels received from these stations may compliment or substitute the signals detected by the aforementioned temperature and humidity sensors.

[0031] In some embodiments the controller may activate a defrost cycle only during daylight hours or based on signal received from an ambient light sensor.

[0032] In some embodiments, the efficiency of the PV element in PV panels and PVT systems is reduced significantly when temperatures are elevated, typically above approximately 25°C. In some embodiments, the refrigerant based thermodynamic panel of the present invention may be at -1°C in operation. In some embodiments, the refrigerant based thermodynamic panel may have a cooling effect on the overlaid PV film. In some embodiments, as a result of being overlaid on top of the refrigerant based thermodynamic panel, the PV film may be prevented from overheating, even when the temperature of the external environment is above approximately 25°C.

[0033] In some embodiments, the cooling effect of the refrigerant based thermodynamic panel on the overlaid film is an example of how the features of the present invention achieve a synergistic effect. In some embodiments, excess heat generated by the PV element can be transferred to the thermodynamic panel, enhancing the efficiency with which energy can be transferred from the environment to an energy storage system.

[0034] One example of how the thermodynamic panels could be produced includes construction from blown cold roll-bonded aluminium. Two flat sheets of aluminium are heated and pressed together by mechanical rollers. A pattern of adhesive is laid on one of the flat sheets prior to the two sheets being laid together. The two sheets adhere together in accordance with the pattern. High pressure air is then forced between the sheets, and where the sheets are not bonded together, a channel is formed. In some embodiments, the thermodynamic panel comprises at least one channel. Where the adhesive is laid appropriately, the channels will form a track or tracks through which, as in the prior art and present example, refrigerant can flow.

[0035] In some embodiments, the walls of the hybrid system panel may be in the region of 0.9 mm. In some embodiments, this may be thicker than thermodynamic panels known in the art, which typically have a thickness of 0.7mm. In some embodiments, the panels of the present invention may be thicker than prior art panels because the hot refrigerant vapour is at a greater pressure than the refrigerant fluid liquid or vapour passing through the panel when the system is running 'normally'. In some embodiments, the increased wall thickness is necessary to contain the increased pressure.

[0036] In some embodiments, the thickness of the panel may be dependent on the refrigerant utilised. For example, when operated with the refrigerant R-134a, the hybrid solar system may require a panel capable of handling a higher pressure than in a system using R-407c.

[0037] Where the thermodynamic panels utilise a refrigerant such as R-744, an equivalent technology that would cope with a higher-pressure fluid may be used.

[0038] In some embodiments, producing hot refrigerant vapour at a higher temperature is advantageous because the domestic hot water supplied at the condenser within the building area can be heated to a higher temperature.

[0039] In some embodiments, the hybrid system panels of the present invention may be mounted in any orientation, in contrast to prior art panels which will only work when they are fixed in a particular orientation. The current panels are also designed with a multiplicity of potential routes for refrigerant flow. Refrigerant entering the panel through an input / output port may split so as to follow any one of a number of routes around the panel before exiting the panel through the other input / output port. However, the panel is specifically designed so that any potential route around the panel is the same distance. The benefits of this design are that pressure distribution around the panel is more even than in a standard panel, so the panel of the present invention absorbs energy from its surroundings in a more efficient manner.

[0040] In some embodiments, the photovoltaic film may be adhered directly to the thermodynamic panel, possibly using a thermally conductive adhesive or a thermal grease. In some embodiments, this contrasts known PVT systems which require mounting of the PV element onto the thermal panel using fixings such as screws. A thermal grease is better suited to accommodate different coefficients of thermal expansion for the photovoltaic film and the thermodynamic panel than screw fixings. In some embodiments, the photovoltaic film may be directly affixed onto the thermodynamic panel. In some embodiments, the photovoltaic film may be affixed to the thermodynamic panel using an adhesive tape, including, but not limited to 3M™ tape. In some embodiments, the photovoltaic film may be affixed to the thermodynamic panel using an alternative fixing technology such as screws or another mechanical fixing.

[0041] In some embodiment, by directly adhering the photovoltaic film onto the thermodynamic panel, the thermal gradients within the system are minimised. This is in direct contrast to known PVT systems which utilise PV cells mounted on top of thermodynamic panels. Such systems have thermal gradients between the two elements which ultimately reduce the efficiency with which energy can be transferred from the environment to the panel.

[0042] In some embodiments, the photovoltaic film is coterminous with the thermodynamic panel.

[0043] In some embodiments, the photovoltaic film may cover part of the thermodynamic panel. In some embodiments, the photovoltaic film may cover substantially the whole of the thermodynamic panel.

[0044] In some embodiments, a coterminous photovoltaic film and thermodynamic panel may maximise the surface area used to generate electricity and increase the efficiency of the electricity production.

[0045] In some embodiments, wherein the thermodynamic panel comprises at least one channel, the photovoltaic film may be provided on an opposite face of the thermodynamic panel to the at least one channel. In some embodiments, the photovoltaic film may cover substantially the entirety of one surface of the hybrid system, whilst the thermodynamic elements may be provided to the rear of the PV film. In some embodiments, this maximises the surface area which can be used to generate electricity.

[0046] Within the context of the present invention, the terms "photovoltaic film" and "PV film" should be understood to refer to any photovoltaic element which is substantially thinner than typical photovoltaic elements, known in the art. The term may encompass a degree of flexibility, although this is not essential.

[0047] In some embodiments, the photovoltaic film may comprise at least one polymer layer. In some embodiments, the photovoltaic film may be a polymer laminate panel.

[0048] In some embodiments, the photovoltaic film may be 0.1 to 1 cm thick. In some embodiments the photovoltaic film may be more than 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9 cm thick. In some embodiments, the photovoltaic film may be less than 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3 or 0.2 cm thick. In some embodiments, the photovoltaic film may be less than 3 mm thick. In some embodiments, the photovoltaic film may comprise 160 pm thick monocrystalline photovoltaic cells.

[0049] In some embodiments the photovoltaic film may comprise a copper indium gallium selenide solar cell containing polycrystalline thin films. A direct bandgap material, CIGS has very strong light absorption and a layer of only 1-2 pm is enough to absorb most of the sunlight. In some embodiments, the CIGS photovoltaic film including thermally conductive adhesive will have a thickness less than 3mm thick.

[0050] In some embodiments, the photovoltaic film may have a weight of up to 2.5 kg / m2for example 2.0kg / m2. In some embodiments, the PV film is significantly thinner than PV cells used in PVT systems known in the art. In some embodiments, the reduced thickness of the hybrid system facilitates a space saving efficiency as well as a reduced weight of the panels compared to other PVT systems. In some embodiments, the PV film may have a honeycomb-geometry, which may further reduce the weight of the hybrid system.

[0051] In some embodiments, the lightweight and space saving nature of the hybrid system can be particularly advantageous for example when used to provide electricity and hot water to multiple occupancy buildings such as apartment complexes, in which the demand for electricity and hot water is high but the roof space available for panel installation is relatively low. In some embodiments, in which the hybrid system is mounted on a roof, the use of a PV film can significantly reduce the load on the roof compared to typical PVT systems, and separate PV and thermodynamic panel systems.

[0052] In some embodiments, the combination of the PV film and thermodynamic panel into a single unit, enables the hybrid system to be installed using a single set of attachments. In some embodiments, this facilitates an increased cost effectiveness of installation and an improved installation efficiency compared with the installation of separate thermodynamic panel and PV systems. In some embodiments, where the hybrid system is installed on a roof, the system may be mounted onto a single set of roof rails.

[0053] In some embodiments, the hybrid system may operate with the refrigerant R-134A. In some embodiments, the hybrid system may operate with the refrigerant R-513A. In some embodiments, it may be preferable to use a refrigerant which is environmentally friendly and increases the efficiency of the hybrid system. In some embodiments, it may be preferable to use the refrigerant R-513A as it is more environmentally friendly than R-134A. In some embodiments, it may be preferable to use the refrigerant 513A because it increases the efficiency of the hybrid system compared to R-134A.

[0054] FIGURES

[0055] Figure 1 shows the hybrid system of the present invention, viewed from above;

[0056] Figure 2 shows the hybrid system of the present invention, viewed from the side;

[0057] Figure 3 shows the hybrid system of the present invention used to generate electricity and domestic hot water; and

[0058] Figure 4 shows a detailed view of the condenser / water tank system. DETAILED DESCRIPTION

[0059] The present invention provides a hybrid system suitable for both generating electricity and also for transferring energy from the environment into an energy storage system.

[0060] Referring to Figure 1, the hybrid system 10 comprises a thermodynamic panel 12 configured to vaporise a refrigerant using heat extracted from the environment. The panel 12 can be mounted in any orientation, in contrast to prior art panels which will only work when they are fixed in a particular orientation. The panel 12 is designed with a multiplicity of potential routes for refrigerant to flow through refrigerant channels 18. Refrigerant enters the panel 12 through the inlet port 14, and exits through the exit port 16. The refrigerant may be any suitable refrigerant including, but not limited to, R-134A, R-407c or preferably R-513A.

[0061] The panel 12 is specifically designed so that any potential route around the panel 12 from inlet port 14 to exit port 16 (or vice versa) is the same distance. The benefits of this design are that pressure distribution around the panel 12 is more even than in a standard prior art panel, and the panel 12 absorbs energy from its surroundings in a more efficient manner.

[0062] A photovoltaic film 20 is overlaid on the thermodynamic panel 12 such that the hybrid system 10 can utilise solar energy to generate electricity. The photovoltaic film 20 may comprise at least one polymer layer or may be a polymer laminate panel. The photovoltaic film 20 may be 0.1 to 1 cm thick and may preferably be less than 3 mm thick. The photovoltaic film 20 may comprise 160 pm thick monocrystalline photovoltaic cells. The photovoltaic film 20 may have a weight of up to 2.5 kg / m2for example 2.0kg / m2.

[0063] Referring to Figure 2, the photovoltaic film 20 is overlaid on top of the thermodynamic panel 12. The photovoltaic film 20 can be adhered directly to the thermodynamic panel 12. A layer of thermal insulation 26 is adhered to the underside of the thermodynamic panel. This thermal insulation layer may cover part or substantially all of the underside surface of the thermodynamic panel. In some alternative embodiments (not shown), the layer of thermal insulation covers only a part of the underside surface of the thermodynamic panel or it may be omitted entirely.

[0064] As shown in Figures 1 and 2, the photovoltaic film 20 and the thermodynamic panel 12 are combined to form a single unit. The photovoltaic film 20 may be coterminous with and cover substantially the whole of the thermodynamic panel 12. Alternatively, the photovoltaic film 20 may cover part of the thermodynamic panel 12. Referring to Figures 3 and 4, a hybrid system 10 used to generate electricity and also to transfer energy from the environment and generate a domestic hot water supply is shown. Although not included in the figures, it should be understood that additionally or alternatively, the hybrid system may transfer heat into an energy storage device such as a thermal battery. As shown in Figure 3, the refrigerant vapour from the panel 12 is transferred to a heat pump 2 for compressing refrigerant vapour from the panel 12. The flow of refrigerant is indicated by the arrows 3 and 3a. The hybrid system 10 further comprises a condenser / water tank system 100 for transferring heat from the hot refrigerant vapour to a water supply. Cold water enters the condenser / water tank system 100, as indicated by arrow 5, travels through a heat exchanger 40 and exits the condenser / water tank system 100 as hot water, as indicated by arrow 7. The controller 90 is configured to manage the refrigerant flow from the heat pump 2 to the condenser / water tank 100. The controller 90 is also configured to manage the flow of refrigerant back to the panel 12, via valves 60A and 60B. Valves 60A and 60B operate in unison to divert the flow of refrigerant to the panel. The flow of hot refrigerant gas back to the panel 12 is indicated by arrows 9 and 9a. The controller 90 may be configured to dynamically control the flow of refrigerant and to optimise the performance of the system depending on the weather / climate in which the hybrid system is being operated.

[0065] Cooled refrigerant passes from the condenser 100 to a liquid refrigerant receiver 13, as indicated by arrow 11. The cooled refrigerant then travels through an expansion valve 6, as indicated by arrow 15 before being supplied back into the panel 12. The system may also comprise a fluid control valve (not shown) configured to enable refrigerant fluid from the panel 12 to pass through the fluid control valve into the heat pump 2 and then back through the fluid control valve into the condenser / water tank 100. The system may also comprise a temperature sensor 22a and / or a humidity sensor 22b configured to measure the temperature and / or humidity of the environment. The controller 90 can be configured to monitor the temperature and / or humidity sensor and to act on the valve 60 in order to divert hot refrigerant vapour back into the panel 12 when the temperature and / or humidity sensors indicate conditions are suitable for frost or ice forming on the system 10.

[0066] Referring to Figure 4, the condenser / water tank system 100 is shown in more detail. The condenser / water tank system 100 comprises a heat exchanger 40 and a water tank 19. Cold mains water is piped into the water tank 19 on demand, as indicated by arrow 5. The cold water passes through the heat exchanger 40 and is then available as a domestic hot water supply, indicated by arrow 7, to taps and so on in areas such as kitchens and bathrooms within the installation building.

[0067] The condenser / water tank system 100 may additionally comprise a temperature sensor 17 within the tank, and an immersion heater 21. This enables the system to run until the tank of water 19 is heated to a certain temperature, and then the hybrid system may stop heating the water. The temperature sensor 17 can be used to determine when the water in the tank 19 drops below a pre-set temperature, which may trigger the system to start heating the water within the water tank 19 again. The hybrid system may comprise a heat storing device such as a thermal battery, which may be used to store thermal energy from the hybrid system when not used to heat water. The condenser system may also comprise an auto-air vent 27.

[0068] The PV film 20 overlaid on the thermodynamic panel 12 produces electrical power which can be used to drive the heat pump 2 for compressing the refrigerant vapour. The PV film 20 may produce electrical power to drive the water circulating pump 25. Excess electrical power generated by the PV film can be used to power the building on which the system is installed, can be fed to the grid, and / or can be used to charge batteries.

[0069] Various further aspects and embodiments of the present invention will be apparent to those skilled in the art in view of the present disclosure.

[0070] "and / or" where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example "A and / or B" is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each is set out individually herein.

[0071] Unless context dictates otherwise, the descriptions and definitions of the features set out above are not limited to any particular aspect or embodiment of the invention and apply equally to all aspects and embodiments which are described.

[0072] It will further be appreciated by those skilled in the art that although the invention has been described by way of example with reference to several embodiments. It is not limited to the disclosed embodiments and that alternative embodiments could be constructed without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS1. A hybrid system suitable for generating electricity from solar irradiance and transferring energy from the environment into an energy storage system, the system comprising: a thermodynamic panel containing a refrigerant, the panel being configured to vaporise the refrigerant using heat extracted from the environment; a photovoltaic film overlaid on the thermodynamic panel; a heat pump for compressing refrigerant vapour from the panel into hot refrigerant vapour, a condenser for transferring heat from the hot refrigerant vapour to an energy storage system; and a controller configured to manage the refrigerant flow from the heat pump either to the condenser or back to the panel.

2. The system according to claim 1, wherein the energy storage system comprises a water tank.

3. The system according to any of the preceding claims, wherein the energy storage system comprises at least one thermal battery.

4. The system according to any of the preceding claims , further comprising: an expansion valve through which, in use, cooled refrigerant vapour from the condenser passes before being supplied back into the panel; a fluid control valve configured to enable refrigerant fluid from the panel to pass through the fluid control valve into the heat pump and then back through the fluid control valve into the condenser; and a temperature sensor and / or a humidity sensor configured to measure the temperature and / or humidity of the environment; wherein the controller is configured to monitor the temperature and / or humidity sensor and to act on the fluid control valve in order to divert hot refrigerant vapour back into the panel when the temperature and / or humidity sensors indicate fall below a threshold value indicative of frost or ice forming on the panel.

5. The system according to any of the preceding claims, wherein the photovoltaic film is adhered directly to the thermodynamic panel.

6. The system according to claim 5, wherein the photovoltaic film is coterminous with the thermodynamic panel.

7. The system according to any of the preceding claims, wherein the thermodynamic panel comprises at least one channel.

8. The system according to claim 7, wherein the photovoltaic film is provided on an opposite face of the thermodynamic panel to the channel.

9. The system according to any of the preceding claims, wherein the photovoltaic film comprises at least one polymer layer.

10. The system according to any of the preceding claims, wherein the photovoltaic film is a polymer laminate panel.

11. The system according to any of the preceding claims, wherein the photovoltaic film is 0.1 to 1 cm thick.

12. The system according to claim 11, wherein the photovoltaic film is less than 3 mm thick.

13. The system according to any of the preceding claims, wherein the photovoltaic film comprises 160 pm thick monocrystalline photovoltaic cells.

14. The system according to any one of claims 1 to 12, wherein the photovoltaic film comprises 2pm thick copper indium gallium selenide solar cell polycrystalline photovoltaic cells.

15. The system according to any of the preceding claims, wherein the photovoltaic film has a weight of up to 2.5 kg / m216. The system according to any one of the preceding claims, wherein the refrigerant is R-513A or R-744.

Images