More particularly, the present invention relates to a temperature control apparatus including an energy store.

BACKGROUND OF THE INVENTION

It has been proposed to use combined heat and power apparatus, CHP, in both domestic and commercial buildings, which contribute both to meeting the demands for electrical power in the building and to heating the building. In some circumstances CHP apparatus may produce sufficient electrical power to meet the supply needs of the building and to feed power back into the electrical power grid.

To achieve the best efficiency from CHP apparatus it may be desirable to use both the electrical power and the heat generated by the apparatus in the building in which it is installed.

The demand for heating in buildings is subject to daily and seasonal variations. Demand for electrical power also varies in a similar periodic or quasi periodic fashion in individual buildings and there are also other short and long term temporal variations in demand for electrical power.

Peaks and troughs in demand for electrical power may be correlated to some degree with the demand for heating, but the degree of correlation is not sufficient alone to permit electricity suppliers to rely upon CHP contributions to address consumer demand for electrical power. The present disclosure aims to address these and related technical problems.

SUMMARY OF THE INVENTION

Aspects of the invention are set out in the independent claim and preferred features are set out in the dependent claims. There is described herein a temperature control apparatus for a building, the apparatus comprising: an electricity generator, operable to contribute to an electrical power supply for appliances at the building; an energy store for storing electrical energy generated by the electricity generator; a heat transfer system adapted to circulate heat transfer fluid to cool the electricity generator and to regulate the temperature of the energy store; and a heat exchange system adapted to provide heat energy for a heating system for the building using heat energy obtained from the heat transfer system.

By providing an energy store (or energy storage module) which can store the electrical energy generated by the generator, it is possible to run the generator to obtain heat energy for a heating system of the house (for example, for a space heater or hot water system) and store any excess electrical energy produced by the generator. For example, this may be advantageous when the heating system requires energy, but electricity demand from the building (and optionally from the electricity grid) is low. The energy stored in the energy store can then be converted into electricity to contribute to the electricity supply of the building (or fed into the electricity grid) when demand for electricity is higher. By circulating heat transfer fluid to regulate the temperature of the energy store, any losses in the form of heat energy during charging and discharging of the energy store can be recovered and used in the heating system of the building. Additionally, it may possible to ensure the energy store is kept at a safe and efficient operating temperature.

Preferably, the heat transfer system is a closed circuit, such that there is no physical contact or fluid communication between the heat transfer fluid and the surroundings (e.g. surrounding air). Preferably, the heat transfer system comprises a fixed quantity of heat transfer fluid, for example so that there is no contribution to the heat transfer fluid from the surrounding and no loss of heat transfer fluid to the surroundings. Preferably, the heat transfer system comprises: a generator heat transfer circuit adapted to circulate heat transfer fluid to cool the electricity generator; and an energy store heat transfer circuit adapted to circulate heat transfer fluid around the energy store. Thus the energy store heat transfer circuit allows regulation of the temperature of the energy store. The energy store heat transfer circuit may also allow heat obtained from the energy store to contribute to a heating system of a building. In some cases it may be preferable to transfer heat from the energy store to a heating system of the building that is kept at a relatively low temperature, such as an underfloor heating system.

Preferably the generator heat transfer circuit is a closed circuit and the energy store heat transfer circuit is a closed circuit, such that they are not in fluid communication with the surroundings or with each other.

Optionally, the heat exchange system comprises: a generator heat exchanger adapted to provide heat energy for a heating system for the building using heat energy obtained from the generator heat transfer circuit; and an energy store heat exchanger in thermal communication with the energy store heat transfer circuit for regulating the temperature of the energy store by transferring heat energy between the heating system for the building and the energy store heat transfer circuit. This may be advantageous as the heat produced by the generator may be quite different from the heat produced by the energy store, and providing different heat exchangers may allow for more efficient heat transfer. In some cases it may possible to run the heat transfer circuits independently, for example if the energy store is not charging/discharging it may be preferable to run the generator heat transfer circuit only. If the energy store is discharging (e.g. supplying electricity to the building) but the generator is not operating it may be preferable to run the energy store heat transfer circuit only. Where the temperature of the energy store decreases below a threshold temperature, it may be preferable to run the heat transfer system to provide heat energy to increase the temperature of the energy store from the building's heating system and/or the generator. In some embodiments, the generator heat transfer circuit is thermally coupled to the energy store heat transfer circuit. This may provide a simpler heat transfer system. In such cases, there may be only a single heat exchanger for transferring heat energy from the generator and the energy store to the heating system (and in some cases from the heating system to the energy store). In some embodiments it may also be desired to heat the energy storage module with heat from the generator.

Preferably, the generator heat transfer circuit is in fluid communication with the energy store heat transfer circuit. Preferably the generator heat transfer circuit and energy store heat transfer circuit comprise a single circuit. This can lead to a simpler system. In such cases, there may be provided a single heat exchanger for transferring heat energy from the generator and the energy store to the heating system (and in some cases from the heating system to the energy store).

Preferably the heat transfer system is operable to maintain the temperature of the energy store within a predetermined range, so that the temperature does not go too high or fall too low. For example, this may ensure the temperature of the energy store remains in a suitable range that helps provide optimal performance (e.g. in terms of charging and discharging) and reduces degradation of the energy store. Preferably, the predetermined range is between 0 degrees Celsius and 50 degrees Celsius; preferably more than 5 degrees Celsius and/or less than 45 degrees Celsius.

Preferably the temperature control apparatus further comprises a controller operable to control the circulation of heat transfer fluid around the electricity generator independently from the circulation of heat transfer fluid around the energy store. For example, the temperature of the generator may be kept within a first temperature range and the temperature of the energy store may be kept within a second temperature range, that is different from the first temperature range.

Preferably, the energy store is coupled to the electrical power supply for the building for providing power for electrical appliances. Thus electrical energy from the generator may be stored in the energy store until it is required in the building.

Preferably, the energy store is coupled to an electricity supply grid and is arranged to supply electrical energy to the electricity supply grid. Thus energy may be stored in the energy store when demand on the electricity supply grid is low (but, e.g. demand for heat in the building is high, so that the generator is running) and supply electricity to the electricity supply grid when demand is high.

The energy store may operate in parallel with an electric grid supply, so that the energy store can meet all or part of the local electrical load (appliances or otherwise) at the building and/or support export to the electrical grid.

Preferably, the energy store is arranged to store electrical energy supplied from the electricity supply grid. Preferably, the energy storage module is coupled to the electricity supply grid via an electricity meter. Thus the electricity meter can measure energy supplied to the grid from the energy storage module. Preferably, the electricity generator is arranged to supply electricity to the electricity supply grid. The generator may also be coupled to the grid via the electricity meter so that the electricity meter can measure energy supplied to the grid from the generator. Preferably the apparatus further comprises a charger for an electric vehicle battery.

Preferably the heat transfer fluid is a liquid. For example, it may be a liquid at the normal operating conditions of the apparatus, for example at the normal temperature and pressure at which the apparatus is run.

In some embodiments the heat transfer fluid comprises glycol, preferably the heat transfer fluid further comprises water. This may ensure the heat transfer fluid does not freeze.

Preferably the apparatus further comprises a heating system comprising a heat source for providing heat energy to a space heater for heating at least one zone of the building and to a hot water tank arranged to store a supply of hot water for the building. There is also described herein a temperature control method for controlling the temperature of a building, the method comprising the steps of: running an electricity generator to generate electricity; storing at least a portion of the electrical energy generated by the electricity generator in an energy store; circulating heat transfer fluid to cool the electricity generator and to regulate the temperature of the energy store; and transferring heat energy obtained from the heat transfer system to a heating system for the building.

Preferably the method further comprises: contributing to an electrical power supply for appliances at the building using the electricity generated by the generator. In some cases, the method further comprises: contributing to an electrical power supply for appliances at the building using energy stored in the energy store.

Optionally, the method further comprises: circulating heat transfer fluid to regulate the temperature of the energy store independently from circulating heat transfer fluid around the electricity generator. Thus it may be possible to keep the energy store and the generator at different temperatures. It may also be possible to regulate the temperature of only one of the generator and energy store. There is also described herein a temperature control apparatus for a building, the apparatus comprising: an electricity generator, operable to contribute to an electrical power supply for appliances at the building; a heat transfer system adapted to circulate heat transfer fluid to cool the electricity generator; a heat exchanger adapted to provide heat energy for a heating system for the building using heat energy obtained from the heat transfer system; an energy store for storing electrical energy generated by the electricity generator; and a charger for an electric vehicle battery, the charger being electrically coupled to the output of the electricity generator and to the energy store such that the electricity generator and the energy store are each operable to charge an electric vehicle battery connected to the charger.

By providing an energy store and a charger for an electric vehicle battery, it may be possible to provide faster charging for an electric vehicle battery than could be obtained from powering the charger from the generator alone. The electric vehicle battery can also provide extra energy storage, for example for when the energy store has no further capacity, but the generator is still running and there is no/low demand for electricity in the building or in the grid. An energy store could supplement excess on-site generation to meet all/most of the charging load for the electric vehicle battery, to prevent increased electrical imports, especially at peak times, with attendant benefits to the entire electricity system. This may be particularly advantageous for use with chargers where the charger has a restriction on grid import capacity. For example, in some applications capacity may be limited to 16A/phase at 230V.

Preferably, the energy store is operable to provide a boost charge current to charge an electric vehicle battery connected to the charger. Thus an electric vehicle battery may be charged faster than if it were charged by electricity provided by the generator alone. Preferably, the electricity generator and the energy store are operable to provide a current for charging the electric vehicle battery of at least 20 amps, preferably at least 30 amps, more preferably about 32 amps. In some embodiments the current may be less than 50 amps, or less than 40 amps. In some embodiments, the charger for the electric vehicle battery is further arranged to supply electricity to the power supply for appliances at the building and/or to the electricity supply grid, from energy stored in an electric vehicle battery connected to the charger. Thus the electric vehicle battery can act as additional storage for electricity generated by the generator. In some embodiments, it may also act as additional storage for electricity from the grid when demand is low so that it can be used in the building or transferred back to the grid when demand is high.

Preferably, the heat transfer system comprises: a generator heat transfer circuit adapted to circulate heat transfer fluid to cool the electricity generator; and an energy store heat transfer circuit adapted to circulate heat transfer fluid around the energy store. Charging electric vehicles can require large amounts of current, which can increase losses, for example into heat energy. By providing an energy store heat transfer circuit, any excess heat energy produced by the energy store charging the vehicle can be transferred back to the heating system of the building. The energy store heat transfer circuit may also ensure that the energy store is at an optimum temperature for fast charging of the electrical vehicle battery.

Preferably, the heat transfer system is further arranged to circulate heat transfer fluid to cool the charger. This may ensure the charger is kept at an optimum temperature for fast charging, and may also mean that any heat losses are recycled in the building's heating system.

There is also described herein a method for controlling the temperature of a building, the method comprising the steps of: operating an electricity generator to generate electricity; circulating heat transfer fluid to cool the electricity generator; transferring heat energy obtained from the heat transfer system to a heating system for the building; storing at least a portion of the electrical energy generated by the electricity generator in an energy store; and charging an electric vehicle battery using energy stored in the energy store. Thus the supply to a charger from electricity generated by the generator or the grid can be supplemented with energy from the energy storage module to increase charging speed.

In some examples, charging the electric vehicle battery using energy stored in the energy store comprises providing a boost charge current, such as a current of around 30A, to increase the charging speed.

Optionally, the method may also comprise charging the electric vehicle battery from the output of the electricity generator and/or from an electricity supply grid. In some cases charging from one or both of these may be performed in conjunction, e.g. at the same time as, charging from the energy storage module. For example, the electricity generator and the energy storage module may both provide a charging current to the charger at the same time. In other examples, the charger may be supplied by power from the grid and from the energy storage module at the same time. In some embodiments, the method further comprises supplying electricity to the power supply for appliances at the building and/or to the electricity supply grid from the electric vehicle battery. When the electric vehicle battery has stored energy, it may be more efficient to power the house or to export energy to the grid from the electric vehicle battery. This may be the case where there is no thermal capacity in the heating system and thus the excess heat produced by operating the electricity generator would not be used.

There is also described herein a temperature control apparatus for a building, the apparatus comprising: an electricity generator operable to contribute to an electrical power supply for appliances at the building; a heat transfer system adapted to circulate heat transfer fluid to cool the electricity generator; a heat exchanger adapted to provide heat energy for a heating system for the building using heat energy obtained from the heat transfer system; a connection for connecting to a charger for an electric vehicle battery, the charger being operable to charge an electric vehicle battery connected to the charger using energy from an electricity supply grid; wherein the charger is electrically coupled to the output of the electricity generator such that the charger is operable to charge an electric vehicle battery connected to the charger using energy from the electricity generator; and wherein the charger comprises charger control logic operable to cause the charger to charge an electric vehicle battery using energy from the electricity supply grid when a set of one or more charger criteria are satisfied; and a controller comprising operational control logic operable to override the charger control logic when a set of one or more operational criteria is satisfied to cause the charger to charge an electric vehicle battery using energy from the electricity generator. Thus an apparatus such as a combined heat and power microgeneration system can be used to provide charging for an electric vehicle. It may be possible to override any existing controls on the charger (such as time charge controls set to limit taking electricity from the grid at peak times, or when there is a high demand for electricity from the grid or not enough electricity entering the grid) to allow charging of the electric vehicle when the generator is producing energy (for example in order to provide heat to the building). The controller may be provided as a separate component from the charger. In some examples the apparatus also comprises the charger. In some embodiments the charger may be a standalone vehicle charger to be connected to the apparatus or an on-board charger on an electric vehicle. In some examples, the operational criteria are based on operational data relating to the electricity generator, the heating system, the electrical power consumption of appliances in the building and/or the electricity supply grid. The criteria may be that the operational data values or a ratio between two of the data values is above or below a certain value or within a certain range. The electricity supply grid may be an interconnected network for delivering electricity from suppliers to consumers; the electricity supply grid may supply electricity to the building. Operational data relating to the electricity generator may include the current temperature of the generator or the amount of fuel available. Operational data relating to the heating system may include the thermal capacity of the heating system, for example if space heaters, night storage heaters or a hot water tank have thermal capacity for storing heat energy obtained from running the generator, and may additionally or alternatively include the current and predicted future thermal demand of the heating system. In some cases, the control logic may be operable to override the charger control logic when a set of at least two operational criteria is satisfied. In some embodiments, the apparatus also includes an energy store for storing energy generated by the electricity generator, and the operational control logic is further operable to cause the charger to charge an electric vehicle battery using energy stored in the energy store if a set of one or more energy store criteria based on operational data relating to the energy store is satisfied, such as the quantity of energy stored in the energy store. Where there are multiple energy store criteria, it may be that only one relates to energy store operation, and others relate to the power consumption of appliances, the generator, the heating system and/or a condition of the electricity supply grid. For example, charging the electric vehicle battery from the energy store may be initiated if the energy store has stored energy and the heating system does not have any thermal capacity (meaning any heat energy produced from powering the generator could not be stored).

Preferably, the operational control logic is operable to cause the charger to charge the electric vehicle battery using energy stored in the energy store at the same time as: using energy generated by the electricity generator; and/or using energy supplied by the electricity supply grid; optionally in order to provide a boost charge current. By providing concurrent charging from multiple sources, it may be possible to charge the electric vehicle battery more quickly. In some embodiments such a current may be less than 100A, less than 50A, less than 40A or less than 35A. In preferred embodiments such a boost current may be around 32A. Optionally, the operational data relating to the energy store comprises an indication of the amount of energy stored in the energy store and/or the current or projected temperature of the energy store. The building control logic may be operable to cause the charger to charge an electric vehicle battery using energy stored in the energy store when an operational criterion relating to the amount of energy stored in the energy store is satisfied.

Preferably, the charger is further operable to supply electricity to the power supply for appliances at the building and/or to the electricity supply grid from an electric vehicle battery connected to the charger. In such cases, the operational control logic may be operable to override the charger control logic to cause the charger to supply electricity to the power supply for appliances at the building and/or to the electricity supply grid from an electric vehicle battery when a set of one or more electric vehicle battery discharge criteria is satisfied. Preferably, the set of one or more electric vehicle battery discharge criteria is based on: the energy stored in the electric vehicle battery; an operating condition of the heating system; and an electricity grid condition and/or the demand for electricity in the building, such as the demand for power from appliances in or connected to the building.

In some examples, the set of one or more charger criteria is based on one or more of: a preset schedule (such as one set by the user and/or by an electricity supplier); an electricity grid condition (such as the supply or demand of electricity in the grid, or in a local area of the grid, or the frequency response); and the demand for electricity in the building (for example the electricity being used by electrical appliances in the building). For example, the charger may be programmed to charge the electric vehicle using electricity from the grid during times of low demand for electricity on the grid and/or from the particular building, or during times where there is ample, or excess, electricity supply one the grid. A preset schedule may be based on a prediction of peak times, or high demand for electricity consumption. This may provide load balancing of electricity on a local scale (e.g. between electrical equipment at the building and the electric vehicle battery charger) and on a wider scale (such as across the whole, or a portion of, the electricity grid). The frequency response and/or constraint managed zones may alternatively or additionally be provided by such a system. Such logic using the charger criteria may provide conventional control of charging, such as allowing charging of the vehicle battery only when electricity is at a certain rate (for example on multi-rate grid tariffs).

In other examples, the set of one or more operational criteria is based on one or more of: an electricity grid condition; an operating condition of the electricity generator; the demand for electricity in the building; the current demand for heat from the heating system for the building; the projected demand for heat from the heating system for the building; and the heat storage capacity of the heating system for the building. In some cases the set of operational criteria is based on at least two of these factors. Thus it can be determined, based on one or more of the operational data values, whether it is more efficient to charge the vehicle battery from the grid or from the generator. Thus it may be possible more efficiently to balance load locally (e.g. between the building and the electric vehicle battery charger, and optionally the local energy store) and also on a wider scale (such as across the whole, or a portion of, the electricity grid). In some cases, it may be that the generator is already running in order to generate heat for the building but the electricity produced by the generator is not all being consumed in the building. In such a case it may be preferable to use this generated electricity to charge an electric vehicle battery at the site, rather than export the electricity to the grid. Thus this may result in the electric vehicle battery being charged by electricity from the generator at a time when conventional controls on the charger would not allow charging.

There is also described herein a method of operating a charger for an electric vehicle battery, the method comprising the steps of: detecting that an electric vehicle battery having capacity for storing energy is connected to the charger; obtaining operational data relating to an electricity generator coupled to a heat transfer system adapted to circulate heat transfer fluid to cool the electricity generator and a heat exchanger adapted to provide heat energy for a heating system for a building using heat energy obtained from the heat transfer system; determining whether a set of one or more operational criteria is satisfied based on the obtained operational data; if the set of one or more operational criteria is satisfied, charging the electric vehicle battery from the output of the electricity generator; if the set of one or more operational criteria is not satisfied , determining whether a set of one or more charger criteria is satisfied; and if the set of one or more charger criteria is satisfied, charging the electric vehicle battery using electricity from an electricity supply grid. Thus the charging of the electric vehicle battery from the electricity generator may be performed regardless of whether or not the charger criteria are satisfied. Thus a positive decision to use electricity from the electricity generator based on the second parameters may result in overriding charging of the electric vehicle battery using power from the grid.

Preferably, the obtained operational data further relates to an energy store for storing energy generated by the electricity generator, and the method further comprises the step of, after determining whether the set of one or more operational criteria is satisfied: determining whether a set of one or more energy store criteria is satisfied based on the obtained operational data; and if the set of one or more energy store criteria is satisfied, charging the electric vehicle battery using energy stored in the energy store. In some embodiments, the electric vehicle battery may be charged from the energy store regardless of whether or not the set of operational criteria is satisfied. In some embodiments, the charger is an on-board vehicle charger and the step of charging the electric vehicle battery from the output of the electricity generator comprises sending a control message to the on-board vehicle charger; and, where applicable, charging the electric vehicle battery using energy stored in the energy store comprises sending a control message to the on-board vehicle charger.

Preferably, the method further comprises the steps of: detecting that the electric vehicle battery connected to the charger has stored energy; determining whether a set of one or more electric vehicle battery discharge criteria is satisfied based on the obtained operational data and the detected energy stored in the electric vehicle battery; if the set of one or more electric vehicle battery discharge criteria is satisfied, supplying electricity to the power supply for appliances at the building and/or to the electricity supply grid from the electric vehicle battery. Thus it may be possible to provide extra energy storage in an electric vehicle battery and use the energy stored in the electric vehicle battery to meet some or all of the electrical energy demands of the building.

In any of the apparatus described above, the temperature control apparatus may further comprise a controller configured to determine how to apportion energy between the building, the energy store and the electricity supply grid based on one or more of: (i) the thermal capacity of the hot water tank; (ii) a temperature schedule specified by a user for at least one zone of the building; (iii) an electricity grid condition; (iv)a weather condition or weather forecast; (v) the electrical charge of the energy store; (vi) the temperature of the energy store; and (vii) the electrical charge of the electric vehicle battery, where present. Thus it may be possible to provide efficient control of energy in the apparatus.

Preferably, the temperature control apparatus further comprises: a heating system comprising a heat source for providing heat energy to a space heater for heating at least one zone of the building and to a hot water tank arranged to store a supply of hot water for the building.

Preferably the energy store comprises an electrochemical energy store, preferably an electrochemical cell. For example, the energy store may be a battery.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments will now be described, by way of example only and with reference to the accompanying drawings, in which:

Figure 1 illustrates a combined heat and power apparatus comprising an energy storage module;

Figure 2 illustrates a combined heat and power apparatus comprising an energy storage module and a charger for an electric vehicle; and

Figure 3 illustrates a combined heat and power apparatus comprising an energy storage module, a charger and for an electric vehicle and a rectifier and inverter arrangement. DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a temperature control apparatus for a building 10. The apparatus comprises an electricity generator 26 arranged to contribute to the electrical power supply 28 available to a consumer at the building 10. The electricity generator 26 may also be operable to feed electrical power back into the electricity supply grid. The apparatus also comprises an energy storage module 30 connected to the power output of the generator 26 and operable to store energy generated by the generator, and optionally to store electricity supplied by the grid. The apparatus also comprises a controller 16 configured to determine the timing of operation of this electricity generator 26 based on the thermal capacity of the hot water tank 18, the demand for space heating in the building 10, one or more grid conditions and/or the amount of energy stored in the energy storage module 30. The apparatus shown in Figure 1 includes a heating system having a space heater 20 and a hot water tank 18. The heating system also has a heat exchanger 24 arranged to supplement heat provided by the heating system's own heat source 22 with excess heat obtained by cooling the electricity generator 26. A generator heat transfer circuit is arranged to circulate heat transfer fluid around the generator 26 to cool the generator.

The heating system's heat source 22 may comprise a fuel burner for example a gas or oil fired boiler. The heat source 22 is coupled to a space heater 20, which may comprise fluid filled radiators for heating one or more zones of the building 10. The heat source 22 is also coupled to heat water to be stored in the hot water tank 18. The hot water tank 18 is arranged to store, and to dispense, a supply of hot water for use by a consumer in the building 10.

The energy storage module 30 is arranged to store electrical energy produced by the generator 26. The energy storage module 30 may comprise a capacitive, inductive, electromechanical or electrochemical storage device. For example, the energy storage module may comprise an electrochemical cell or battery, or a fuel cell.

The energy storage module 30 may be coupled directly to the electricity output of the generator 26, without the need for an additional rectifier. In embodiments where the generator 26 generates alternating current (AC), there may be a rectifier, which converts the AC to direct current (DC) and then an inverter which converts the DC into three- phase AC suitable for powering appliances in the building 10 and for feeding into the electricity supply grid. In such cases the energy storage module 30 may be connected between the rectifier and the inverter, so that a further rectifier for converting AC into DC that is suitable for charging the energy storage module 30 is not required.

In embodiments where the generator 26 generates DC electricity, there may be an inverter for converting the DC into three-phase AC which is suitable for supplying the building 10 with electricity and for feeding into the electricity supply grid. By directly coupling the energy storage module 30 to the DC generator output, another rectifier for converting the AC into DC suitable for charging the energy storage module 30 is not required. Reducing the number of inverters and rectifiers between the generator output 26 and the energy storage module 30 can reduce power and heat losses that occur at each stage of conversion between AC and DC.

The energy store 30 may be connected to the electrical power supply for the building 10 (and optionally to the electricity supply grid) via an inverter for converting DC into three-phase AC suitable for providing power to appliances in the building 10. In some cases, the energy store 30 may be connected to the electrical power supply for the building 10 (and optionally to the electricity supply grid) via the same inverter that connects the electricity output of the generator 26 to the power supply for the building 10. The energy store 30 may be connected to the electricity supply grid so that it can supply stored energy to the electricity supply grid and/or store energy provided by the electricity supply grid. For example, the energy store 30 may operate in parallel with electric grid supply, so that it can meet all or part of the local electrical load at the building 10 (e.g. appliances or otherwise) and support export to the electrical grid (where export accounts for all or part of the instantaneous power output of the energy store 30 at any time).

In some embodiments the energy storage module 30 is connected to the electricity supply grid via an electricity meter. The generator 26 may also be connected to the grid via the electricity meter. The electricity meter may be arranged to measure electricity supplied to the building 10 from the electricity supply grid. The meter may also measure electricity supplied to the grid from the electricity generator 26 and the energy storage module 30. A generator heat transfer circuit is arranged to circulate a heat transfer fluid around an engine of the electricity generator 26 to remove excess heat from the generator, and to provide the heat transfer fluid to the generator heat exchanger 24, which may be arranged inside the building 10. For example the generator heat exchanger 24 may be arranged in a zone of the building 10 which is at least partially heated by the heating system.

The heat exchanger 24 is coupled to the heating system and adapted to supplement the heat energy from the heat source 22 with heat energy obtained from the generator heat transfer circuit.

In some embodiments the generator heat transfer circuit is a closed circuit; i.e. it is sealed so that there is no fluid communication between the heat transfer fluid and the external environment. The generator heat transfer circuit thus may contain a fixed amount or quantity of heat transfer fluid.

The heat transfer fluid may comprise a fluid with a melting point of less than zero degrees centigrade, for example the heat transfer fluid may comprise glycol. The heat transfer fluid may be liquid at the operating conditions of the apparatus, e.g at the normal range of operating temperatures and pressures. In some embodiments a phase change material may be used. For example a phase change material may be used for heat storage and/or as the heat transfer fluid, for example the interface between the energy storage module 30 and/or the generator 26 and the heating system of the building 10. In some embodiments there is also provided an energy storage module heat transfer circuit. The energy storage module heat transfer circuit is arranged to circulate a heat transfer fluid around at least a portion of the energy storage module 30 to regulate the temperature of the energy storage module 30. In some embodiments, the energy storage module heat transfer circuit may be a closed circuit such that it is not in fluid communication with the generator heat transfer circuit or with the surrounding environment. In such embodiments, the energy storage module heat transfer circuit may optionally be thermally coupled to the generator heat transfer circuit (not shown). The energy storage module heat transfer circuit may also or alternatively be thermally coupled to the heating system of the building 10, for example via a second heat exchanger or, as shown, via the same heat exchanger 24 which couples the generator heat transfer circuit to the heating system..

In alternative embodiments, the energy storage module heat transfer circuit may be in fluid communication with the generator heat transfer circuit, such that the heat transfer fluid can flow between the generator heat transfer circuit and the energy storage module heat transfer circuit. In such embodiments, the energy storage module heat transfer circuit can thus be coupled to the heating system via the same heat exchanger 24 which couples the generator heat transfer circuit to the heating system.

In some embodiments it may be desirable that the generator heat transfer circuit and the energy store heat transfer circuit are not in thermal communication. Then it may be possible to control the temperature at the energy storage module separately from that at the generator.

Excess heat from the energy storage module 30 (e.g. heat energy produced during charging of the energy storage module 30) may be transferred to the heating system via the energy storage module heat transfer circuit. Thus heat energy losses which occur during electrical charging and discharging of the energy storage module 30 may be recovered and used in heating the building 10, which leads to greater energy efficiency. It may be particularly advantageous to couple the energy storage module heat transfer circuit to components in the heating system which provide low-to-moderate amounts of heat to the building, for example to underfloor heating systems. In addition, heat energy may be transferred to the energy storage module 30 from the heating system and/or from the generator 26 (when the energy storage module 30 heat transfer circuit is in thermal communication with the energy storage module 30 heat transfer circuit). Thus the energy storage module 30 may be protected from high temperatures, which can lead to degradation and reduced storage life, and from low temperatures which may result in slower charging and discharging and may also be detrimental to energy storage. For example, batteries such as lithium-ion batteries may perform better at temperatures between 5 and 45 degrees Celsius. At temperatures below freezing (0 degrees Celsius) electroplating of metallic lithium can occur at the negative electrode during a subfreezing charge. Providing such temperature regulation for the energy storage module 30 may be particularly advantageous when the energy storage module 30 is situated outside the building 10, and thus subjected to extremes of temperature. Thus operational efficiency of the energy storage module 30 may be improved, as well as improving thermal efficiency and reducing thermal losses across the system.

The heating system may comprise a user interface 12 to enable a user to select a desired temperature for the building 10. The user interface 12 may comprise a human input device such as buttons, switches, a touch screen or a pointing device, and one or more output devices such as a screen or other display means. For example, the user interface 12 may be arranged to allow a user to select a desired temperature for a particular zone of the building 10 such as a room or collection of rooms. Generally the user interface 12 is also operable to select at least one first time period during which the desired temperature is to be maintained - for example the user interface 12 may be operable by a user to select a start and a duration or end time for the space heating. Generally, when operating the space heating, a consumer may select a time period in the morning, and perhaps also another time period later in the day during which a desired temperature is to be maintained. The user interface 12 may also be operable to allow a user to specify at least one second time period during which the consumer wishes to be able to dispense hot water from the hot water tank 18.

The hot water tank 18 has a certain thermal capacity associated with the quantity of water that the tank 18 is able to store, the fill level of the tank 18 at any given time, and the temperature of the water in the tank 18.

The hot water tank 18 may comprise one or more sensors arranged to provide fill level and temperature signals to the controller 16 to enable the controller 16 to determine the thermal capacity of the tank 18 and/or the thermal demand associated with meeting the consumer's demand for hot water. The heating system may also comprise one or more temperature sensors arranged to provide signals to the controller 16 indicating the temperature of one or more zones of the building 10 and perhaps also the temperature outside the building 10. In some embodiments the heating system may also comprise temperature sensors for sensing the temperature of the generator 26 and/or of the energy storage module 30. In the interest of clarity these sensors are not illustrated in Figure 1 . The controller 16 may be coupled to a communications interface 14 for communicating over a network such as a wireless and/or wired network such as a local area network (LAN) which may be coupled to a wide area network, for example a telecommunications network, for example the internet, for communicating with a remote device, for example a device in a different geographical location than the building 10. The controller 16 may also be configured to communicate with one or more of the other components of the apparatus shown in Figure 1 via this communications interface 14 for example over the LAN and/or via a serial communications BUS which may operate according to a MODBUS protocol. The electricity generator 26 may be configured to report data such as voltage and frequency available at the mains electricity supply 28 in the form of a CANBUS message, and the controller of the CHP system may be configured to translate the data from CANBUS to another protocol such as MODBUS. The controller may also be configured to receive a MODBUS command, for example from the user interface 12 or in the form of a message received over the communications interface 12, and to translate the MODBUS message into a CANBUS command to start or stop operation of the electricity generator 26. The MODBUS interface may comprise MODBUS RTU (serial), but in some embodiments may also comprise MODBUS over a data network protocol such as IP and/or TCP data networks.

The controller 16 may be adapted to report the thermal capacity of the building 10 - for example the thermal capacity of the hot water tank 18 and/or the thermal demand associated with the space heating to a remote device via this communications interface 14. The controller 16 may also be adapted to obtain (and optionally to report) data from the electricity generator 26 indicating the voltage and/or frequency of the external mains electricity supply to the building 10.

The controller 16 may also be adapted to obtain (and optionally to report) data from the energy storage module 30 relating to the charging status of the energy storage module 30, for example the amount of potential energy stored in the energy storage module 30 and/or the voltage across the energy storage module 30. The controller 16 may determine whether to switch on the generator 26 based on the charging status of the energy storage module 30. The controller 16 is configured to obtain data indicating the thermal capacity of the hot water tank 18, for example it may be configured to determine this based on the sensor signals from the hot water tank 18. It is also configured to determine a thermal demand of the space heating. This determination may be based on one or more of the sensor signals, the desired temperature for the zone (or zones) of the building 10 associated with these temperature sensor signals, and the time period during which the consumer has selected that this temperature is to be maintained.

In operation of the hot water system, the controller 16 obtains data indicating the thermal capacity of the hot water tank 18, and if the thermal capacity of the hot water tank 18 is greater than a selected threshold level, the controller 16 may switch on the electricity generator 26 and operate the heat exchanger 24 to heat water to be stored in the hot water tank 18, this threshold level may be selected based on the heat output of the heat exchanger 24 to ensure that the electricity generator 26 is switched on for a time period at least 1 minute, for example at least 5 minutes, for example at least 30 minutes in order to fulfil the thermal capacity of the hot water tank 18. The controller may also obtain data indicating that the thermal capacity of the hot water tank has been exceeded (e.g. the water is over temperature), or that the thermal capacity is less than a selected threshold level and, may determine based on this data to switch off the electricity generator 26.

The controller 16 may receive an indication of one or more electricity supply grid conditions, for example, a measure of the electricity supply, such as the power available to the electricity grid, or of the electricity demand, such as the power being consumed from the electricity grid by users. The controller 16 may determine whether to switch on the electricity generator 26 based on the received indication of the electricity supply grid condition. In some embodiments the controller 16 may determine whether to switch on the electricity generator 26 based on the electricity supply grid condition and the charging status of the energy storage module 30, and optionally the power demands of the building 10. For example, if the controller 16 determines that based on the grid condition it is not suitable to supply electricity to the grid, then the controller 16 may run the generator 26 to supply electricity for storage in the energy storage module 30 based on the charging state/storage capacity of the energy storage module 30.

The controller 16 may be arranged to control the thermal conditions of the generator 26 and/or of the energy storage module 30. For example, the controller 16 may control the generator heat transfer circuit to operate when the generator 26 is switched on and/or when it is determined (e.g. from a temperature sensor at the generator 26) that the generator 26 is above a threshold temperature. For example, the generator 26 may continue to give off excess heat after it is switched off, so it may still be efficient to transfer that excess heat to the building. The controller 16 may also control the energy storage module heat transfer circuit to circulate heat transfer fluid around the energy storage module 30 when the energy storage module 30 is charging or discharging. Alternatively or additionally, the controller 16 may also control the energy storage module heat transfer circuit to operate when the temperature of the energy store 30 is outside a predetermined range (measured by one or more temperature sensors located within or adjacent to the energy storage module 30). Thus the controller 16 may ensure the energy storage module does not overheat, that any excess heat energy created in the charging/discharging of the energy storage module is recaptured, and/or prevent the energy storage module from falling to a detrimentally low temperature (for example below a threshold temperature). In some embodiments, the temperature of the energy storage module 30 may be regulated only when the energy store 30 is charging or discharging. For example, it may be dangerous or detrimental for the energy storage module 30 to be at too low a temperature whilst it is charging, but it may be inefficient to keep the energy storage module 30 above a threshold temperature continuously. Thus the controller 16 may cause the energy store heat transfer circuit to operate when the temperature of the energy store 30 is outside a first predetermined range whilst the energy storage module 30 is (dis-)charging and may cause the energy store heat transfer circuit to operate when the temperature of the energy store 30 is outside a second predetermined range (different from the first predetermined range) whilst the energy storage module 30 is not (dis-)charging.

The controller 16 may control the operation of the energy store heat transfer circuit separately or independently from the operation of the generator heat transfer circuit. In some embodiments the controller may maintain the energy store above a first temperature threshold and below a second temperature threshold, and may maintain the generator below a third temperature threshold. In some embodiments the controller may operate the energy store heat transfer circuit when the energy store above a first temperature threshold and below a second temperature threshold, and may operate the generator heat transfer circuit when the generator is below a third temperature threshold. The third temperature threshold may be the same or different from the second temperature threshold. The second and third temperature thresholds may depend on a setpoint temperature of a space in the building 10.

In order to balance the geographical distribution of power supply on the electricity grid, the controller 16 may receive a command to stop supplying electrical energy to the electricity grid, for example the command may be received from a remote device via the communications interface 14. The controller 16 may respond to this command by determining whether the quantity of hot water stored in the hot water tank 18 is sufficient to meet the user's requirements, and in the event that it is not, the controller 16 may switch on the heat source 22 to heat hot water for the hot water tank 18.

In some embodiments the controller 16 may respond to a command to stop supplying electricity to the electricity grid by causing the electrical energy generated in the generator 26 to be stored in the energy storage module 30, particularly in the case where the quantity of hot water stored in the hot water tank 18 is insufficient to meet the user's requirements. Thus it may be possible to continue heating the hot water tank 18 without resorting to using the heat source 22.

In some embodiments, the controller 16 may respond to a command to start supplying electricity to the electricity supply grid by causing energy stored in the energy storage module 30 to be supplied to the grid. For example, this may be desirable if the electrical energy stored in the energy storage module 30 is above a certain threshold, the thermal capacity of the hot water tank 18 is below a certain threshold and it is not possible to continue to run the electricity generator 26 without overshooting the desired temperature of the property 10.

In operation of the space heating system, prior to the start of a first time period during which the user has selected a desired temperature for a zone of the building 10, the controller 16 switches on the electricity generator 26 and uses the heat exchanger 24 to at least partially preheat the space heater 20 and/or the zone of the building 10.

The controller 16 may then identify when the temperature of the space heater 20 and/or the zone of the building 10 has reached an equilibrium state, for example based on detecting that the rate of change of temperature is less than a selected threshold or by operating the electricity generator 26 and heat exchanger 24 for a selected duration. At the end of this preheat phase, and prior to the start of the first time period, in the event that the temperature of the zone remains less than the desired temperature, the controller 16 may operate both the electricity generator 26 and the heat source 22 together to heat the zone. The switch on time of the generator and heat source 22 for this dual-heating period may be selected to achieve the desired temperature of the zone at the start of the first time period.

Whilst, as mentioned above, the controller 16 may be configured to receive commands to switch off the electricity generator 26 during this dual-heating phase, the controller 16 may also be configured to increase the duration of operation of the electricity generator 26. For example towards the end of the dual-heating (ramp-up) heating phase, as the zone approaches the desired temperature, the controller 16 may be configured to switch off the heat source 22 of the heating system prior to switching off the electricity generator 26 whilst continuing to monitor the temperature (and perhaps also the rate of change of temperature) in the zone of the building 10. The controller 16 may then determine whether it is possible to continue to run the electricity generator 26 without overshooting the desired temperature - for example the electricity generator 26 may be run at all times when space heating is desired.

Figure 2 shows a temperature control apparatus for a building 10 as described above in relation to Figure 1 , further comprising a charger 32 for an electric vehicle battery. The electric vehicle battery charger 32 is coupled to the electricity generator 26 so that an electric vehicle battery connected to the charger 32 may be charged with electricity generated by the electricity generator 26. The charger 32 for an electric vehicle battery is also coupled to the energy storage module 30, such that an electric vehicle battery connected to the charger 32 may be charged using energy stored in the energy storage module 30. In some embodiments the charger 32 is an on-board charged integrated into the electric vehicle, whereas in other embodiments the charger 32 is a standalone charger to which an electric vehicle can be attached for charging.

The electric vehicle charger 32 may be supplied by the generator 26 alone (when the generator 26 is switched on), by the storage module 30 alone (e.g. if the generator 26 is not switched on and the energy storage module 30 has stored energy), or by both the electricity generator 26 and the storage module 30. In some embodiments, the electric vehicle charger 32 can be additionally or alternatively supplied with electricity from the electricity supply grid.

Thus the charger 32 may operate in different modes. One or more of the modes of operation may be controlled, or initiated, by commands from the controller 16. If it is detected that an electric vehicle battery that needs charging, or has capacity for storing more electricity, is connected to the charger 32, and the generator 26 is running (e.g. because of a heat demand in the building from the heating system, such as from the hot water tank 18 or space heater 20), the charger 32 may charge the electric vehicle battery using electricity generated by the generator 26. If an electric vehicle battery that needs charging is detected but the generator 26 is not running, the controller 16 may decide to start the generator 26 to provide electricity for charging the battery, or it may instruct the charger 32 to charge the electric vehicle battery using electricity from the grid and/or from the energy store 30. Such a decision may depend on one or more criteria, such as conditions or parameters, and may be based on operational data regarding the operation of components in the system, such as the state or condition of the electricity supply grid and/or the heat or electricity demand from the building. In yet another mode of operation, an electric vehicle battery that is connected to the charger 32 and has stored energy may be used to contribute to the electrical power supply for the building or to the electrical grid. The controller 16 may enable supply of electricity to the building/grid from the electric vehicle battery based on the operation of the generator 26 (e.g. whether it is operational, its temperature), the heat capacity of the heating system, the current/projected heat demand for the building, the demand for electricity at the building, an operational condition of the energy store (e.g. its current stored charge, its temperature) etc.

In some embodiments the controller 16 may send commands to the charger 32 to override conventional commands initiated e.g. by the charger 32 itself. For example, the charger 32 may comprise a processor which allows charging of an electric vehicle battery dependent on certain criteria, such as the state of the electricity grid or the time of day (e.g. a preset timetable or dynamic instructions -peak or cheap rate times). The controller 16 may be configured to send commands to override such conventional commands based on the state of the generator 26, the energy store 30 and the heat demand from the heating system in the building 10. The power supplied to the charger 32 by the electricity generator 26 (or the grid) can be supplemented by the energy storage module 30 in order to create a larger current (or "boost" current) for faster charging of the electric vehicle battery than could be supplied by the generator 26 or electricity supply grid alone. For example, in some embodiments it may be possible to provide a current of more than 20A, preferably more than 25A, more preferably more than 30A. In some embodiments such a current may be less than 100A, less than 50A, less than 40A or less than 35A. In preferred embodiments such a boost current may be around 32A. A boost charge current may be provided to charge the vehicle battery using power from the energy store 30 to supplement (e.g. by using it at the same time) energy from the grid or generator.

In embodiments where the energy storage module 30 supplies a high boosting current to the charger 32 to charge an electric vehicle battery quickly, the provision of an energy store heat transfer circuit may be particularly desirable, as energy losses via heat during high current discharging can be greater.

In some embodiments, the charger 32 may be arranged to supply the building 10 and/or the electricity supply grid with electrical energy from the energy stored in an electric vehicle battery. Thus additional electrical storage can be provided when the electricity generator 26 is operating to provide heat energy to the building 10, but the electricity generated is not required by the building 10 or by the electric supply grid. The electric vehicle charger 32 may support DC export to an inverter, for example to convert into three-phase AC that is suitable for feeding into the power supply for the house and for feeding into the electricity supply grid. In some embodiments the same inverter that converts DC from the energy store 30 into AC for the building 10 or grid may be used to convert DC from a battery connected to the charger 32 into AC.

In some embodiments, the charger 32 may be connected to the DC output of the generator 26 adjacent to where the energy store 30 is connected, so that there is no requirement for current from the generator 26 and energy store 30 to be converted into AC and then rectified into DC suitable for charging the battery. Thus there may be less power lost in the conversion between AC and DC (such as heat losses).

In some embodiments, there may also be a charger heat transfer circuit for regulating the temperature of the charger 32. This can allow for excess heat produced during high current charging of the battery to be reused in the heating system of the building 10. Thus there may also be a heat exchanger that is arranged to transfer heat from the charger heat transfer circuit to the heating system. Figure 3 shows temperature control apparatus for a building 10 as described above in relation to Figures 1 and 2, but further illustrating an example of AC-to-DC conversion.

The energy storage module 30 shown in Figure 3 is coupled to the electricity output of the generator 26, without the need for an additional rectifier. In the embodiment shown in Figure 3, the generator 26 generates alternating current (AC), and there is a rectifier 34, which converts the AC to direct current (DC). There is also an inverter in a circuit 36 positioned before the electrical power supply 28 at the building 10, which converts the DC into three-phase AC suitable for powering appliances in the building 10 and for feeding into the electricity supply grid. The energy storage module 30 is connected between the rectifier 34 and the inverter in the circuit arrangement 36, so that a further rectifier for converting AC into DC that is suitable for charging the energy storage module 30 is not required. When the energy store 30 supplies electricity to the building 10 or to the electricity supply grid, the inverter 36 may convert the DC supplied by the energy store 30 into AC suitable for appliances in the building 10 and/or for the grid.

Where the energy store 30 is arranged to store energy provided by the grid, the circuit arrangement 36 may also comprise a rectifier. Thus AC provided by the grid may be converted into DC suitable for charging the energy store 30 by the rectifier of the circuit arrangement 36. Alternatively, a separate rectifier may be provided.

In embodiments where the generator 26 generates DC electricity, the rectifier 34 may be omitted.

Reducing the number of inverters and rectifiers between the generator output 26 and the energy storage module 30 can reduce power and heat losses that occur at each stage of conversion between AC and DC. In the embodiment shown in Figure 3, the charger 32 is connected to the DC output of the generator 26 adjacent to where the energy store 30 is connected, so that there is no requirement for current from the generator 26 and energy store 30 to be converted into AC and then rectified into DC suitable for charging the electric vehicle battery. For example, there is a direct connection between the energy store 30 and the charger 32, and the rectifier 34 is between the generator 26 and the charger 32. Thus there may be less power lost in the conversion between AC and DC (such as heat losses). When the electric vehicle charger 32 is supplied by power from the grid, the AC from the grid may be converted into DC suitable for charging the electric vehicle by a rectifier in circuit arrangement 36.

When the electric vehicle charger 32 is operable to supply power to the grid or to the power supply of the building 10, the inverter in the circuit arrangement 36 may convert DC from the charger into AC suitable for appliances at the building 10 or for feeding into the grid, e.g. three-phase AC.

However, in some embodiments the electric vehicle charger 32 will have its own rectifier and inverter arrangement for converting between DC for charging the electric vehicle battery and AC supplied to/from the grid, from the generator or to power appliances in the building 10. In such embodiments, the inverter of circuit 36 may be positioned between the connections to the energy storage module and connections ot the charger 32.

Any system feature as described herein may also be provided as a method feature, and vice versa. As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure. Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to system aspects, and vice versa. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination. It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently. The above embodiments and examples are to be understood as illustrative examples. Further embodiments, aspects or examples are envisaged. It is to be understood that any feature described in relation to any one embodiment, aspect or example may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, aspects or examples, or any combination of any other of the embodiments, aspects or examples. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.