WO2023285772A1

WO2023285772A1 - An electric heating and hot water system incorporating an energy controller and a method of operating an electric heating and hot water system

Info

Publication number: WO2023285772A1
Application number: PCT/GB2022/000062
Authority: WO
Inventors: Christopher Charles Farrell
Original assignee: Christopher Charles Farrell
Priority date: 2021-07-15
Filing date: 2022-07-01
Publication date: 2023-01-19

Abstract

A novel heating and hot water system is provided that incorporates a thermal store which is heated under the control of a controller for the purposes of improved real time energy control. The controller is arranged to be responsive to patterns of energy use and energy tariffs.

Description

An Electric Heating and Hot Water system incorporating an energy controller and a method of Operating an electric heating and hot water system

This Patent application claims priority from GB 2110206.6 filed 15 July 2021 and from GB2112288.2 filed 27 August 2021.

Background to the invention

Many countries are looking to reduce their carbon dioxide emissions.

In May 2021 the International Energy Agency, IEA, reported that the world needs to stop installing gas boilers and switch to electric heating and hot water services by 2025 in order to prevent irreversible climate change. The UK government, like many others, is seeking to decarbonize energy usage and is looking to ban sale of internal combustion engine vehicles and to switch houses from gas heating to greener alternatives which are electrically powered.

This is likely to cause stress to the national supply grid. As a result of which the utility companies are likely to have to resort to supply rationing, either directly or by imposing tariffs that seek to modify consumer’s behavior by virtue of the cost of using electricity.

Summary of the teachings of this disclosure

According to a first aspect of this disclosure there is provided a method of providing at least one of space heating and potable hot water in a building or dwelling, where the building or dwelling uses electricity to provide its at least one of space heating and potable hot water, and where the building or dwelling has: a thermal store that is electrically heated and where heat from the thermal store can be used to provide hot water for use in the provision of at least one of space heating and hot potable water; and a controller for controlling the electrical heating input to the thermal store; and wherein the controller is adapted to be responsive to a measurement of the current being used by the building or dwelling and to a time varying energy cost in order to vary the amount of electrical energy being used to heat the thermal store to vary the energy cost. Preferably the thermal store is operable to provide heat for space heating and for potable hot water. In an embodiment the thermal store is a potable hot water store that provides domestic hot water to outlets and heat to indirect space heating services such as to underfloor and/or low temperature space-heat emitters (e.g. large radiators). Advantageously the thermal store includes an electrically configurable water return circuit to control dynamic thermal stratification of the store. There may be a plurality of thermal stores. This allows temperature recovery to be better controlled. It also allows energy use to be better controlled since the volume of water that needs to be heated may be reduced by only heating one store. The stores may be of different volumes.

Advantageously the electrical heating of the thermal store is adjustable over a plurality of non-zero values. For example over a range of several kW such as, but not limited to 3kW, 6kW and 9kW, 15kW, 24kW. This can be achieved modulating the supply to a specific heater, or using multiple heaters of the same or different heating capacities. In some embodiments the amount of electricity used to provide heating to the thermal store is adjustable up to a maximum value which substantially matches a maximum permitted current draw to the building or dwelling. For example the amount of electricity used to provide heating to the thermal store is adjustable up to a maximum value where the maximum value is greater that 6kW and less than a maximum permitted current draw to the building or dwelling. For a dwelling having a nominal maximum current supply of 40 A this would correspond to 9.6kW at 240V or 8.8kW at 220V.

Preferably the controller is informed of or learns the likely pattern of use of heating and potable hot water within the building or dwelling and schedules heating of the thermal store to reduce the energy cost. Advantageously the controller is informed of or learns the likely pattern of energy cost variation and schedules heating of the thermal store to reduce the energy cost.

Preferably the controller is adapted to be responsive to measurements of current drawn by other devices within the dwelling and more specifically the current drawn by respective ones of the devices and is adapted to communicate with a device or a power controller associated with the respective device to vary the power supplied to the device. A power controller may be able to control the power drawn by a plurality of devices. In this way the current to the heater or heaters used to heat the thermal store can be modulated to keep the total current drawn to within the maximum permissible current available from the mains electricity supply.

Advantageously a user interface is provided such that users can register with the controller, and advantageously a user can inform the controller of their specific heating or hot water requirements.

According to a further aspect of this disclosure there is provided a heat and/or hot water system comprising an electrically heated thermal store and a controller for controlling heating of the thermal store, wherein the controller is responsive to a measurement of the current being drawn from a supply having a nominal maximum current value, and the controller is operable to modulate the amount of current used for heating the thermal store in response to the measurement of current.

The supply having a nominal maximum current value may be the metered supply provided to a building or to a dwelling.

Preferably the controller is responsive to information about a time varying energy cost and is arranged to schedule heating of the thermal store to reduce operating costs of the system. It is thus possible to preferentially heat the store when electricity is less expensive.

Preferably the thermal store comprises a first heater for heating water in the thermal store where the first heater is an electrically powered heater. Advantageously the system further comprises a first heat exchanger in communication with the water in the thermal store for supplying heat from the water in the thermal store to a heat transfer medium of a space heating circuit. Advantageously the first electrical heater comprises a resistive element. In some embodiments of this disclosure the system further comprises a second heater for heating water in the thermal store. The second heater may be a second electrical heater or heat exchanger adapted for connection to a further heat source. The further heat source may be a natural gas boiler, an LPG boiler, a hydrogen boiler, an oil fuel boiler, a mixed fuel boiler, a heat pump, a solar thermal heater or a combination of such heat sources. The system may be arranged to cooperate with a further heating system, such as a gas heating and hot water system. The store, or in embodiments having multiple stores one or more stores may provide pre-warmed water (possibly blended with the cold main to an intermediate temperature) to a boiler or other instantaneous water heater for further heating to provide warm water for longer and/or at an enhanced flow rate.

Preferably the controller is adapted to estimate at least one of a heating demand and a hot water demand within a period of time and to heat the store to the target temperature sufficient to meet the heating and/or hot water demand within that period of time. The period of time may be user defined and is likely to be in the range of 1 to 12 hours. In some embodiments the thermal store has a variable target temperature calculated by the controller as a function of an expected heating and/or hot water load in response to a measurement of external temperature or to a predicted external temperature and the thermal store is heated to the variable target temperature. The controller may, for example, alter the temperature of the store based on the creation of a heating or hot water energy factor derived from a regional or national calculation methodology used in the assessment of energy needs of building.

In some embodiments of this disclosure the controller may be responsive to warnings of high energy demand on an electricity supply to modify the target temperature to increase it to facilitate meeting an expected heat demand and to store additional energy to protect against short term power cuts or short term tariff increases. Such warnings may be issued by a service provider based on knowledge of general system load, knowledge of planned or unplanned generator outages, weather forecasts and even television schedules. In some embodiments the controller’s operation is distributed between a local unit and a remote service such as a cloud based service. Use of a cloud based service enhances the ability to monitor, for example, the scheduled TV programme timetable to manage the heat input to the system through the predictive use of other electrical needs that might otherwise overload the electrical supply capacity of the supply and/or the supplying electricity meter. Such predicted needs may be for example, but not limited to, the use of electric kettles during advert breaks and half time periods of sporting events. Similarly such a controller working in cooperation with a cloud based software service, where the software service may have data inputs from, for example, weather data, national grid capacity data and known events that drive high dynamic electrical loads across the national grid are monitored by the system so as to enable predictive management of the system’s heating and hot water loads. This helps protect system users from potential power failures by rationing electrical input to the system during critical event periods. Alternatively, the system may predict such an event and increase the temperature of the store in readiness for a critical event that would otherwise limit heating and or hot water service delivery. The controller may also recommend alternative heating and hot water use times based on predicted loads to help protect the user’s required use of the heating and/or hot water services.

Preferably the controller is arranged to schedule and/or inhibit the operation of electrical loads as a function of cost or current drawn from the supply.

Thus there is provided a system where the controller is informed of or learns the likely pattern of use of heating and potable hot water within the building or dwelling and schedules heating of the thermal store to reduce the energy cost and or in which the controller is informed of or learns the likely pattern of energy cost variation and schedules heating of the thermal store to reduce the energy cost. With this knowledge the controller can warm the store or allow it to cool so as to improve heat management (cost to heat and temperature recovery) of the store. For example the controller may predictively allow one or more stores to cool through the use of heating and hot water services so as to lower the residual hot water temperature in the store or stores that corresponds with that of the lowest useable temperature of the store prior to heating and hot water off periods, or when little demand is predicted.

Advantageously the controller also seeks to control thermal stratification within the store caused by warm water being less dense than cooler water. The store may include a secondary circulator to circulate water within the store. The circulation path may include multiple re entry points to the store which may be controlled by valves, such as a diverter valve. Thus the diverter valve may be used to alter the flow path of the returning hot water either to aid in the temperature distribution within the store or to actively create lower temperature thermal stratification within the store. This allows the controller to actively create and manage thermocline zones through temperature stratification and disruption of the thermocline in order to improve heat transfer through the indirect space heating heat exchanger within the store. Creation and management of active thermoclines helps manage temperature zones including the disruption of the cooled water barrier that forms a thermally resistive heat transfer barrier around indirect heat exchangers. The controller may also energise the heater and circulator to provide legionella and frost protection control.

In a further aspect of this disclosure there is provide a method of controlling an electrically operated heating and hot water system, the method comprising predictively controlling the amount of electrically generated heat input to the system in response to variable electricity price tariffs and real-time electrical current loads through the supplying electricity meter.

There is also provided a thermal store comprising a vessel for containing water, a heat exchanger passing though the vessel and at least one electrical heater controllable to provide varying levels of heat for heating water in the thermal store.

According to a further aspect of this disclosure there is provided a power controller responsive to a measurement of current at a measurement node, wherein the power controller can control the amount of power being used by at least one device to adjust the current flow at the measurement node so as to keep the current at the measurement node to less than a maximum permitted value.

The measurement node may be in the supply to a dwelling or building. The measurement node may for example correspond to the amount of current at the electricity supply meter used for billing purposes.

The power controller may control some loads to store energy based on knowledge of or expectations of cost of energy. Thus if the energy supplier has a time varying tariff the controller may seek to control a load to store energy at times of relatively reduced cost.

The controller may be able to control the rate at which a device stores energy and may adjust the current flowing to the device to increase the storage rate to corresponding to the maximum current permitted at the measurement node.

Brief description of the Drawings

Embodiments of the present disclosure will now be described by way of non-limiting example with reference to the accompanying figures, in which: Figure 1 shows the relative contribution of energy sources to the UK energy use in 2019;

Figure 2 is a diagram showing relative use of oil in the UK in 2019 by categories of non energy use (feedstock), non-domestic building use, industry use, domestic use and transport;

Figure 3 is a schematic diagram of a heating and hot water system constituting an embodiment of the present disclosure;

Figure 4 is a schematic diagram of a heating and hot water system constituting a second embodiment of this disclosure;

Figure 5 schematically illustrates a building having insulation appropriate to electrical power limitations of an electrically heated heating system;

Figure 6 schematically illustrates various electrical loads within a dwelling and how they can be associated with devices to monitor the current drawn by a load and/or to switch the load on and off under the direction of the controller;

Figure 7 is a graph illustrating how dynamic pricing may cause the cost of electricity to vary over time during part of a day; and

Figure 8 illustrates part of a user interface to the controller.

Description of embodiments of this disclosure

To put the present disclosure in context it is worthwhile considering the following factors:

1) What proportion of energy is electrical?

2) How is energy use broken down by category?

3) Energy supply to the home

4) The time varying nature of energy use in the home

1) What proportion of energy use in electrical? Figure 1 reproduces chart 1.6 from https://assets.publishing.service.gov.uk/govemment/uploads/svstem/uploads/attachment data/ file/9246Q5/DUKES 2020 Chapter l.pdf This shows that in the UK in 2019 the total amount of energy consumed was equivalent to approximately 150 Million Tonnes of oil and of that total only the equivalent of 28 million Tonnes was provided by electricity, i.e. roughly 19%. In this figure “other” corresponds to industrial feedstock.

Furthermore the UK still has to import electricity. For example “The Times” (of London) reported on 5 August 2021 at page 42 that in July 2021 the UK imported 15% of its electricity. However the UK government is committed to driving a change to move consumers away from fossil fuel in homes and as a fuel for automobiles. At the time of writing electrical power demands grow as consumers switch to Electric Vehicles and electric heating. It’s well documented that power supplies are likely to struggle to cope with the increased demand. However, what’s less well understood is that electricity meters, including new smart meters, are not designed for these coming energy loads.

2) How is the energy used?

Chart 1.5 of the same document found at https://assets.publishing.service.gov.uk/govemment/uploads/svstem/uploads/attachment data / file/924605/DUKES 2020 Chapter l.pdf (presented here as Figure 2) shows that Domestic fuel use was equivalent to roughly 40 Million Tonnes of oil while transport use accounted for about 55 Million Tonnes of oil. Consequently the conversion of transport from petroleum to electrical power will have a huge impact on amount of electricity that needs to be generated and distributed.

3) Energy supply to the home

The UK has an established national gas grid that supplies gas to most homes in cities, towns and large villages. Rural dwellings are unlikely to be served by the national gas grid, but can use LPG or oil. If we consider the majority of houses, then they get their energy from the gas grid and from the national electricity grid. However these have different capabilities.

Considering electricity, until recently, electricity was seen as an expensive and more polluting second choice for heating and hot water due to the higher energy costs, lower generating efficiency to useful heat and limited scope of market ready solutions that operate within the capacity of standard issue, 40 A, 60 A, 80A or 100 A electricity supply meters. Electricity was initially generated by burning coal. Around the 1990’s gas (which had previously been perceived as too important to be wasted being burned to make electricity) started to be used for electricity generation. However the fact remains that useful fuel is burnt at a power station to boil water to make electricity which is then distributed to users. At each stage of this process some of the original energy is lost. The UK government recognizes that useful energy is lost (compared to the theoretical maximum energy content of the fuel used by the power station) and this loss is measured by the use of a Primary energy Factor, PEF. The PEF for gas is -1.15/1 whereas the PEF for electric is 4.5/1 but this becomes reduced by the calculated benefit of wind/solar that lowers electricity PEF to 2.8 and 2.5/1 in 2024.

In the UK house fuses were often 30Amp or 60Amp. Many houses are capable of accepting 80 or lOOAmp fuses (or circuit breakers) without needing an upgrade to the cables supplying the property. However after 100A most properties require modification of the cables that supply the house. Even the maximum size 100A fuse limits the maximum power draw to 24kW. For a 60 Amp fuse the maximum power draw is 14.4kW.

Meanwhile homes that use gas for heating, are mostly fitted with a U6 standard meter that provides the equivalent power in terms of electricity of 60kW. Therefore, there is a great difference between the maximum rate of energy delivery of an existing gas meter compared with an 18kW to 24kW limit at an electric meter. Thus gas provides much more energy (or at least a greater delivery rate) to a dwelling than electricity does.

In reality the average UK domestic electricity meter has only about 23% (18/(18+60)) of the power supply capacity of existing and combined gas/electric meter installations. It is clear that if we move from a mixed gas and electric scheme to an all-electric environment then providing enough current to support all home services including heating and/or hot- water and Electric Vehicle charging presents obvious and significant challenges.

Thus a significant infrastructure upgrade is required, both in terms of generation capacity but also distribution capacity.

The UK Government recognizes the need to update the electricity supply infrastructure and to this end is installing millions of Smart Meters into homes and businesses that provide the capability for energy suppliers to tame or limit electrical loads across the grid through variable time-based tariffs and/or through forced disconnection of loads via “demand side response”.

Industry stakeholders, including the Chartered Institute of building Services Engineers, CIBSE, recognize that limited electricity power issues are real and have been generally well managed within the scope of the available power generation and supply limits. To help tame demand across the network, CIBSE, stipulates that the maximum potential installed load for a domestic meter is 120% of meter capacity. For power needs above this value, the home owner must upgrade to a 3 phase supply. 3 phase is typically required to charge Electric Vehicles from home or operate power intensive Air Source Heat Pumps and air-conditioning units. The typical cost of such an upgrade can be £8,000 or more per home. Of course that assumes that even if the supply to a home was upgraded that the desired power for all of the homes is available from our generating and storage facilities.

To help mitigate over loading the power grid, a new BSI Public Accessible Standard, PAS 1878 is proposed that will allow the grid supply operators to automatically control the power usage of domestic appliances including heat pumps used in the generation of domestic heating and hot water services.

4) The time varying nature of energy use.

Energy use within a home varies significantly over the course of a year and also over the course of a day. 4.1) Seasonality

The following table (table 1) shows measured data for a 3 bedroom house in the UK over a calendar year. The energy usage depends on things such as the weather so if the experiment were repeated we would expect different results. However what can be seem is that the domestic hot water energy use varies between 101 kWh in July and 168kWh in January. This is predominantly because of variation in the temperature of the water in the cold main as it enters the house being much warmer in summer than in winter. Consequently a boiler has to impart a much smaller temperature rise to get to a domestic hot water temperature of around 45C.

Table 1

However it can be seen that the space heating requirement varies from OkWh in summer to 2524kWh in winter (roughly 8 lkWh per day in January). Factoring in the domestic hot water use this conies to around 85 kWh.

4.2 Daily patterns

In a home about 1/3 of the daily energy use occurs close to when occupants get up. For example for a family that gets up at 7am, the heating may be instructed to start increasing the room temperature from 6am onwards to reach a warmer value by 7am. The occupants then get up, boil the kettle, make breakfast and/or shower. These energy intensive activities may be complete by 8am when people leave to travel to work and the central heating system may be scheduled to switch off until late afternoon when the occupants return.

Bringing these observations together we might expect around 28kWh of the daily energy use in January (the most power hungry month) to be around 7-8am. Taking the UK as an example, most of the space heating and domestic hot water load is provided by a gas boiler. The most popular type of gas boiler installed in the UK are combination boilers. Combination boilers are compact units, providing instantaneous heating and hot water while removing the need for a large hot water cylinder. That said, combination boilers have some fundamental drawbacks. For example during the winter months they are less able to produce domestic hot water without having to reduce the water flow rate due to the colder incoming mains water supply. To counter this loss of seasonal performance, combination boilers have steadily increased their heat input ratings, in some cases to over 50kW, thereby lowering efficiency and increasing harmful greenhouse gas emissions.

Additionally, gas boilers are most likely to fail during winter months when heating and hot water requirements are most critical. For example, on average the UK installs over 4,000 new gas boilers each day while the majority of these are crises purchases, experienced as emergency boiler replacements during the winter heating months. However gas boilers do provide a truly staggering proportion of the energy used in a home. If gas boilers are not installed in homes, either because of legislation stopping them being installed in new houses or replacement becoming unavailable for old boilers then the electricity system has to take up a considerable additional load.

Doubling the in-use efficiency of electricity for space heating and hot water services in the home is now thought possible due to the introduction of heat pumps. These devices use a reverse refrigeration cycle to generate and release heat that increases the useful heat output of electricity by upwards of ~2.5 times the consumed energy at the plug.

Heat pumps are seen as an attractive option for many homes and the Government is backing this technology for installation in UK homes. The heat pump industry is still in a relative early stage of development and presents home owners with complex challenges in how to satisfy their expectations and achieve the expected levels of efficiency. This problem becomes more acute as the temperature falls as the performance coefficient of air-source heat pumps decreases with ambient temperature. In other words they work less well of cold days, which is the time that heating demand rises. Ground source heat pumps present their own problems in terms of disruption during installation. The use of heat-pumps could reduce the daily heating load to around 40k Wh (except when it’s very very cold). Similarly the “first hour” load could be expected to be reduced from 28kWh to something in the 10 to 15kWh range. However this is still very tight on maximum supply limits. Many dwellings are not suitable for installation of air source heat pumps. Similarly the number of ground source heat pumps that can be deployed in a residential area is limited by the need to avoid creating permafrost conditions.

Therefore, the UK’s 29 million ~80A, 18kW electric meters require a minimum of 2.5 x capacity upgrade to cope with the typical dynamic “first hour” energy loads for heating/hot water. The above discussion has not even considered the additional electricity use resulting from EV charging and everything else in the home.

Mitigating the problem

As discussed above, electricity supplies will be called upon to cope with increased power demands. These demands will manifest in a couple of ways: firstly much more power will be required on average from the electricity supply infrastructure; and secondly the supply structure will have to cope with variations in load which if left unchecked would be bigger than those it currently experiences.

Therefore, if there is no solution to cap or mitigate home owner’s use of grid supply services (but as noted before standards are being developed to allow remote control of devices to inhibit or modify their operation to protect the power grid) then nations will likely introduce super high electricity tariffs to dissuade consumers from using power hungry devices at critical times of the day.

This may result in energy companies having to use pricing as a way of moderating our use of electricity. The utility companies may respond with a tariff increase around the 7am peak demand to encourage the use of optional or non-time critical loads (washing machines, tumble dryers etc.) to be delayed until the demand subsides. Lately home battery packs have become more prevalent. A search as of August 2021 shows that 2.4k Wh of storage could be purchased (but not installed) for £1700 and 7.2kWh of battery storage purchased and installed for £4300. However batteries are not the only way of storing energy within a household.

Many houses have spaces for hot water stores in the form of immersion cylinders. Water has a specific heat capacity of 4.2kJ/Kg/C. For a 100 liter cylinder this means 420kJ are stored per degree centigrade. For a store used in conjunction with a central heating system a temperature of 30 degrees Celsius may be considered as a minimum usable temperature, but the water in the store could be heated up to 85 or 90 degrees Celsius safely. Taking 90 degrees Celsius for convenience this gives a usable energy store of (90-30)*4200*100 J = 25,200,000J or roughly 25MJ of energy. Since lkWh equates to 1000*60*60=3,600,000 or 3.6MJ of energy it can be seen that the 100 liter water tank can store around 6.9kWh of energy in this scenario. Unlike batteries the use of a water store doesn’t suffer from significant storage degradation after several hundred cycles and the risk of fire is much reduced. Whilst the energy stored in a battery can be used for many purposes the energy in the water store can only be used for the supply of space heating or hot potable water, but the inventor realized that these are precisely the loads that dominate the energy use in the domestic environment.

Insulated water cylinders in this size can be acquired for around £200 as of 2021. That is very cost effective compared to a battery storage of electricity.

An embodiment of the present disclosure is shown in Figure 3 and comprises of a potable hot water store 10 that provides domestic hot water to taps as well as space heating via a heat exchanger, for example, a serpentine coil 20, providing a means for a fluid flow path to space heat emitters. Another embodiment of the store may also comprise of primary heating water, or another medium, to provide domestic hot water to taps via a serpentine coil or plate to plate heat exchanger, providing a fluid flow path for the purposes of heat exchange to domestic hot water services.

In the embodiment as shown in figure 3, store 10 has a cold water inlet 12 for receiving cold water from a connection to a cold water main. The store 10 also has a water outlet 14 for providing water to hot water taps (facets) around a building. The store 10 is provided with at least one electric heater. The store 10 is, in this embodiment, heated by electric heaters 16 and 18 which are in the form of “immersion heaters”. The store 10 also includes a first heat exchanger 20. The first heat exchanger 20 has ports 22 and 24 through which a heat exchange medium can be admitted into and removed from the first heat exchanger 20.

In order to prevent temperature stratification a pump 30 is provided to circulate water between an upper region of the store and its middle and/or lower portions. In the embodiment shown the pump 30 is in fluid flow communication with the top of the store 10 and can be operated to return water via an electrically operated diverter valve 32 to the store at a mid-store port 34 or a lower most port 36.

The store 10 may have one or more temperature sensors provided to monitor the water temperature at different points within the store 10. In the embodiment shown in Figure 3 a first temperature sensor 40 is provided to monitor the temperature at an upper region of the store and a second temperature sensor is provided to monitor the temperature is a lower portion of the store. Further sensors may be provided if desired.

A flow sensor 50 is provided to monitor when potable water is being drawn from the store 10. The flow sensor can be provided in the inlet pipe 12 as shown here or the outlet pipe 14.

The electrical heaters 16 and 18 can be energized under the control of a controller 60. The electrical connection (be that power or control signals) between the heaters and the controller 60 is represented by the chain lines extending between them. Similarly the pump 30, diverter valve 32, temperature sensors 40 and 42 and the flow sensor 50 are in communication with the controller 60 to provide data to the controller or be controlled by the controller (as appropriate) and these communication and/or paths are also represented by chain lines.

An electrical supply to the property/house is represented by live 64 and neutral lines 66 which provide electrical power to various electrical loads 68. A current sensor 70 is arranged to measure the amount of current being drawn and to provide this information to the controller 60. The current sensor could be of any suitable technology. Inexpensive technologies include a Flail sensor, or inductive sensors such as current clamps or a Rogowski Coil. Returning to the first heat exchanger 20, the ports 22 and 24 may be directly connected to a space heating circuit 80 as shown in Figure 3. The space heating circuit may comprise one or more radiators 82 or under floor heating loops 84 in conjunction with a pump 86 (also under the control of the controller 60). The space heating circuit 80 may have a further heat exchanger 90 that allows the heating network to receive heat from a further heat source 92.

In an alternative arrangement shown in Figure 4 the ports 22 and 24 of the first heat exchanger 20 may be connected by way of valves, such a diverter valve 95 such that, in a first mode, the first heat exchanger 20 can be solely in fluid flow communication with a space heating network 80 so as to extract heat from the store 10 and provide heat to the space heating network. In a second mode the first heat exchanger 20 is connected solely to the further heat source 92 so as to receive heat from the further heat source so as to heat the water in the store 10. The valve/valves may also support a third mode where heat can be received from the further heat source 95 while the space heating circuit is in use.

The further heat source may be or include heat pumps, solar thermal units, fuel cells, natural gas boilers, LPG boilers, hydrogen gas boilers, solar Photo-voltaic and/or a single or multiple electric heaters that may have varying kW power ratings. Typically, the kW rating for immersion heaters would be matched to the heating and hot water needs and to the available electricity supply characteristics. For example, a standard 3kW immersion heater requires approximately, ~13A, a 6kW ~26A and so forth, whereas domestic electricity supply is available in various sizes having nominal current limits including but not limited to 40A, 60A, 80 A to 100 A. Alternatively, the electricity supply may be upgraded to a 3 phase supply supporting higher Amperage loads. Therefore, there is a balance to be struck between the available electricity supply, thermal efficiency of the building and its heating and hot water needs.

For a new build or refurbished property 110, as shown in Figure 5, increased thermal insulation 116 can be used to lower heat input needs and therefore, the power requirements from the electricity supply can be reflected in the sizing of the store 10, heat exchanger 20, and immersion heaters 16 and 18. However, the inventor has realized that the majority of existing buildings have lower thermal efficiency than new buildings built to higher efficiency standards. Therefore, it’s likely that the required dynamic electrical loads from new electrically operated heating and hot water systems would place an unacceptable strain on the electricity demands of the supplying meter/ fuse/circuit breaker relative to its maximum amperage rating.

To prevent this situation from arising and to enable higher power electrical heating and hot water systems to be installed in buildings, with the type of installed electrical supply meters to be normally found in domestic properties the inventor has realized that if the system controller 60 were aware of the electrical supply’s ( meter’s) maximum amperage rating, and was aware of the instantaneous (or near instantaneous current) being drawn from the current sensor 70 then it becomes possible to manage the current being drawn by the heaters 16 and 18. The controller may be provided as a hardware unit in wired or wireless communication with the various components of the hot water and heating system. However advantageously the controller may be a distributed device. For example the sensors or heaters may be remotely addressable. Each device may be assigned an IP address or way of identifying a device and controlled by way of internet style commands either delivered by wireless communication within a dwelling or sent over existing wiring, such as the mains supply (as is already done by powerline adaptors). Once the controller becomes a distributed device one or more of its functions can be exported to remote computing facilities. Thus the controller 60 may act as a gateway to a cloud based software service. Thus the heating and hot water system can be aware of the maximum electrical supply current available from the metered supply, as well as the real-time dynamic electrical demands through the meter/supply, these being continuously communicated to the system controls. Therefore, it becomes possible to both predict future electrical demand periods and provide a further energy management and electrical load control for improved energy efficiency, energy cost reductions and critically to prevent the overloading of the supplying meter’s maximum rated output.

For heating and hot water systems that are predominately heated from electricity supplied by the supplying electric meter, then it is now possible to significantly increase electrical loads of the heating and hot water system during otherwise low electrical power periods, by installing higher power electrical heaters within the system to the maximum viable rate of the meter’s amperage capacity. Advantageously, the combined power management and available additional kW heat input to the store provides a system owner with the ability to maximize low tariff electricity benefits, provide faster reheat and improved energy efficiency through better managed heat input to heat output requirements.

Given that there is inevitably some heat loss from the store 10 the controller may seek to let the store temperature fall naturally overnight. If the cost of electricity does not vary by time of day, the controller may then seek to warm the store from, say, 5 am onward. However if the energy provider uses dynamic pricing then the controller may vary its strategy based on price. For example, windy conditions may result in an over-supply of electricity from wind turbines. If this was to occur at time of low demand, then the supplier may drop the energy tariff for a short period of time to encourage users to take energy from the grid. Thus, for example, the price of electricity could drop for a short time (say 20 minutes) due to excess generation capacity early in the morning. The controller can respond to this cheap electricity by seeking to fully heat the water store. This may require drawing 6kWh of energy in 20 minutes, being equivalent to an 18kW load. This may equate to roughly the maximum current that can be drawn from a non-upgraded electricity supply. To do this it can be seen that the maximum heating power of the water heaters is much greater than would have been the case in prior art immersion heater systems. Also the controller needs to monitor the current being drawn to make sure that the heating load is modulated to take account of other loads so that the heating is as rapid as possible without exceeding the current supply limit of the dwelling.

Additionally, the electric heat input loads may be time phased to improve energy efficiency, control higher energy costs or general load needs such as at times when other electrical loads limit the systems dynamic heat input.

A dwelling may comprise multiple loads of different types, as shown in Figure 6. These might be divided into different categories depending on whether the load can be delayed or time shifted. For example cookers 200, electric ovens and kettles might be seen as priority loads which must always be serviced immediately. The same might be true of televisions and computers. These can be assigned priority 1. Loads such as freezers 210 can be delayed a bit without problem, so might be identified as priority 2. Washing machines 220 and tumble dryers can generally be delayed for several hours and might be identified as priority 3. Loads such as vacuum cleaners 230 may be classified as truly discretionary and given a lower priority, priority 4. Electrical vehicle charging hub 250 may be given a dynamic priority allocation if the controller knows when a journey is likely to be made. Thus if a user indicates that a vehicle is required to drive to work each morning and the journey distance and time has also been identified then the controller can give the electric vehicle a low priority if the vehicle already has sufficient charge. If the vehicle has an insufficient charge the priority can be set based on the duration to the next expected journey and elevated as time progresses.

Each of the loads may be fitted with an individual current monitoring and switching device 200 A, 210A, 220A, 230 A. The electric vehicle charging station can already be expected to include current monitoring and control capability. Each current monitoring and switching device can communicate with the controller 60 either by a dedicated communication link such as link 252 to the electric vehicle charging hub 250 (such a link may be wireless) or by using power line technology to send data over the mains wiring as is the case for monitoring and switching devices 200A 210A 220A and 230A.

Thus for each device the controller 60 can be appraised in real time of the load the device is drawing and/or whether an attempt is being made to turn a device on. Thus the controller can look at the prevailing current load and enable the switching of priority 2 priority 3 and priority 4 devices on (as appropriate) when their demand can be serviced, taking into account all the other loads to make sure that a maximum current is not exceeded. Advantageously the controller also takes electricity cost into account. In some cases this may include suggesting that some loads (such as the vacuum cleaner) be delayed to a time when power is less expensive. Suggestions that a load should be deferred may be made via an app or web page, or by a power controller associated with the load. Thus a power controller may be provided as a module that may be interposed between the plug of the appliance and the wall socket (e.g. effectively take the place of the plug (or be a smart plug) to give an audible or visual indication that it would be advantageous to delay use of the appliance. Alternatively or additionally the power controller may pulse the device on and off a predetermined number of times and if the user still continues to try and use the device this can be taken as an indication that the user wishes to use the device now. Where a load controller is associated with a refrigerator or freezer it may be adapted to monitor the temperature of the freezer. Thus a freezer could be allowed to warm a bit more than usual when electricity is comparatively more expensive and may even be set to target a lower temperature when electricity is comparatively less expensive. As noted earlier the move to more use of renewable energy can result in mismatches between when electricity is being generated and when consumers wish to use it. The most obvious example of this occurs in the context of space heating which is generally required in winter just when solar panels contribute little or nothing to the electricity supply. However large wind farms can be expected to be more productive in winter and may result in quite a large amount of power being generated when most people are asleep and businesses shut. This may result in providers using smart meters to set a low tariff price, as show in in Figure 7 between midnight and 3 am. The price might change during the night, getting reduced further in this example between 3 and 4am. Then as increasing numbers of people get up, wash and eat, and as heating systems come on the overall demand from the grid rises and the real time electricity price may rise reaching a peak between 06:15 and 08:30 in this example before starting to reduce again as people leave home. If these changes become predictable or are flagged in advance by the electricity providers it becomes possible to move some loads from relatively costly periods to less costly periods. Thus, the controller 60 may decide to warm the water in the store 10 between 3 and 4am to reduce the user’s heating costs. This paradoxically may slightly increase the amount of energy that the user uses (due to loss from the store) but reduces the user’s energy bill.

During the transition to electric heating from gas, the UK and other countries face critical primary energy, electrical generating and distribution challenges that potentially may lead to the failure of the national supply grid to be able to meet these challenges.

The inventor recognized that it is known that weather related impacts, TV schedules and/or but not limited to, other significant national events can place predictably high levels of electrical demand on the electrical supply grid at critical times that may lead to the future failure of the electrical supply network and therefore, power cuts.

To help protect electricity grid supplies against potentially damaging power cuts, the controller 60 in cooperation with a cloud based software service may receive data updates from information sources. Such sources may include but not limited to, the UK’s Met Office, the Balancing Mechanism Reporting System, BMRS, or entrepreneurial sources including grid.iamkate.com. Other equivalent services can be expected to exist in other countries. Information received about potentially damaging future events help inform the controller 60 either alone or in cooperation with a cloud based software service to assess the need to predictively raise the temperature of the store, and or to phase the electrical heat inputs during the critical event, so as to lower the dynamic electrical current required during the significant event period. Additionally, the controller and such a controller in cooperation with the cloud- based software service can inform the users and suggest alternative times for pre-planned heating and hot water needs that coincide with the predicted future critical event.

In operation, the store 10, provides the heat energy and resource needs for both space heating and hot water. For ease of explanation, these needs are discussed separately below.

Domestic Hot Water

The store is heated by the heaters 16 and 18 under the control of the controller 60. The controller may work in cooperation with a cloud-based software service or merely work from previously input or learned user load patterns. As noted before the controller 60 works in cooperation with multiple sensors and device input/outputs, including current sensor 70 to determine dynamic power available to the system, a calendar and clock to determine the time of day and year, optionally a cold water temperature sensor provided to measure cold water as it is admitted into the store, cold water supply flow sensor 50, temperature sensors 40 and 42, hot water circulator pump 30 and diverter valve 32.

The controller and optionally a cloud-based software service allows for pre-scheduled hot water needs, based on the requirements of registered users to the system. The controller 60 is optionally in communication with a cloud-based software service 200 (Figure 5) where a software service enables the system’s users to define certain criteria about the future heating and hot water requirements, including but not limited to, specific user characteristics and predictable hot water needs. For example, users may work during nights, or have a pattern of use that the controller 60 can determine. For example, if a user pre-schedules a bath for 8pm the following day, the software application recognizes this requirement and cooperates with the controller 60 to ensure that hot water is available for the bath or conversely prevent the store 10 from being unnecessarily heated. The control of the target water temperature within the store may take into account multiple inputs, and depend on the operational state, i.e. whether it is within a space heating period, or hot water only timed period. Therefore, the required temperature/ target temperature of the store and consequently amount of heat energy required to be in the store will vary greatly across the day. Furthermore such a daily temperature profile will change with the day of the week and month of the year.

A system strategy that enables users to proactively plan the use of domestic hot water helps inform users of the opportunity to save energy, emissions and lower their energy bills.

Advantageously the system also controls a factored hot water temperature of the store. In other words the temperature to which the store is heated may vary over the year. This factor may be achieved by the conversion of monthly energy outcomes of a regional or national calculation methodology, such as that used in UK building regulations, called, UK/SAP. UK SAP determines variable monthly energy needs of buildings. The hot water energy needs can therefore be factored into a variable store temperature in order to save energy. For example a domestic hot water store is typically set at 60 Degrees Celsius, this being required to ensure sufficient hot water and prevent issues of legionella bacterial growth. However, if we consider that due to seasonal issues the actual hot water energy required in the store could be expressed as a range of temperatures. Taking the hot water heating load of the table 1 as an example, the range is lOlkWh (P water min) in July to 168kWh (P water max) in January. This range or more precisely the expected month power requirement compared to P_water_min can be used to derive a temperature correction factor which may then be used to modify the target temperature of the water store during heating. For example the target temperature may vary from 45 Degree C during the peak summer months to 75 Degree C during cold winter months. Using such a scheme the store 10 may be reduced in volume or the performance of a space limited store improved, allowing for the higher temperature hot water during the winter months and cooler, therefore reduced volumes in the summer months.

This temperature control of the domestic hot water store introduces the concept of weather compensated controls normally associated with space heating into the domestic hot water domain.

Additionally the store may be allowed to cool during the final hours of a heating or hot water period. The hot water heating period may for example be based on a 24 Hour day. The controller (optionally in cooperation with a cloud based software service) may instruct the store temperature to cool through continued use of hot water until such a temperature is reached that the system is then ready to sleep for the overnight period, or be reheated with low cost electricity, and to a different temperature, in readiness for the next heating and or hot water period.

As noted before the controller 60 works in cooperation with sensors that provide information including but not limited to, temperature sensors, 40 and 42. Also the controller 60, optionally in cooperation with a cloud based software service learns the temperatures and usage pattern of hot water requirements from recorded data about the historical flow rates, frequency and temperatures of the incoming cold water supply.

The controller optionally in cooperation with a cloud based software service receives information about the store temperature and combines this with registered user needs to formulate a store temperature strategy. For example, the controller 60 may slowly raise the temperature of the store by limiting the electric immersion heater inputs to reduce energy losses and meet predictive demands. Conversely, if the controller predicts that no demand is needed for some time to come, then the controller may choose to allow the store temperature to cool through use or standing losses to a base operational temperature. The base operating temperature might be ~45 Degree C or nearer to ambient temperature depending on, but not limited to, the time of day or historical use patterns. The controller 60 optionally in cooperation with a cloud based software service may also integrate the on/off periods for circulator pump 30 and diverter value 32 to further control the energy efficiency and store temperature regime.

Thus the controller 60, optionally in cooperation with the cloud based software service records and assesses real time electrical loads through the supplying electricity meter so as to ensure efficient use of electricity through the supplying meter whilst complying with a maximum current draw for the electricity supply.

Also, when the system is connected in concert with passive energy generation devices, for example but not limited to, photovoltaic solar panels or at least one wind turbine, then the controller can convert this power into heat energy within the store or alternatively, if one is available, save power to an electrical battery storage device for later use, for example, but not limited to, for use when the electricity tariff is higher, therefore reducing demand during the most expensive operational periods of use. Therefore, the controller and optionally such a controller in cooperation with the cloud based software service is able to utilize multiple energy inputs and outputs in order to reduce grid dependency and costs while still achieving user needs.

The hot water system shown in Figure 3, operates with a controlled hot water priority. When domestic hot water is required by a user, the controller 60 optionally in cooperation with a cloud based software service, identifies the temperatures of the upper and lower region of the store by way of sensors 40 and 42, the flow of water and its temperature from combined flow rate and temperature sensor 50, and depending on these sensor readings may elect to start/stop circulator pump 30, reposition valve 32 or stop any space heating operation, for example by depowering space heating pump 86. Also, at a time determined by the controller 60 optionally in cooperation with the cloud based software service, the system activates one or both immersion heaters 16 and 18, within the limits of the available electrical power. For example, during winter months the system controller monitors the fluctuating store temperature relating to domestic hot water and space heating needs. The objective is to achieve the lowest acceptable temperature of the store (as this minimizes heat loss from the store) while still meeting the user needs.

User needs may vary between dwellings not only due the fabric of the dwelling but also by the nature of its occupants, for example a household with a young child may want heating and hot water to be prioritized at all times (almost irrespective of the cost) whereas a household with young adults but no children may be less concerned about the availability of hot water and heat levels at any given time of day and may instead prioritize the cost of energy. There is of course a continuum of options between these extremes and a “master priority” may be set for the system by virtue of a slider or dial on a controller interface (such as an app). Such a user interface is shown in Figure 8.

Indeed individual users may identify themselves to the controller and specify their individual preferred hot water requirements so that the controller can seek to meet the potable hot water demands whilst seeking to reduce costs but also seeking to assure an acceptable level of system performance. Users may identify their presence in the house by any suitable means, but given that most people have mobile phones a convenient way is for a wireless interface to detect the presence of individual user’s phones for example via the phone connecting to the house Wi-Fi.

Space Heating

The store 10 provides heat for space heating via the heat exchanger 20, such as a serpentine coil, that enables a heat exchange flow path for the primary space heating liquid.

As homes become increasingly thermally efficient, there is a corresponding lowering of the heat energy required to maintain a comfortable temperature in the property.

For home owners transitioning from gas to electric, and in comparison to existing domestic gas meters, the equivalent supplies (as limited by the main fuse, master circuit breaker and/or electric meters) have only about -25% of the nominal energy supply capability of gas. Therefore, for a lower heat input of an electric based heating system to utilize a standard electric meter’s maximum capacity, there must be a corresponding level of thermal insulation to ensure that the lower heat input levels are able to meet the space heating demands.

Advantageously, lower space heating capability, promotes the use of lower temperature radiators and/or underfloor heating systems, that in turn may benefit from weather compensation that works in cooperation with the controller 60 and/or the controller in cooperation with a cloud based software service to control the temperature of the space heating store temperature for the benefit of lower heat inputs and energy costs.

Advantageously the space heating utilizes pumped underfloor heating manifolds. Each manifold can support multiple heating loops that are time and temperature controlled, by way of activating the manifold circulator to draw heat energy via store 10.

The heat exchanger in store 10 includes a primary heating flow and return sensors 23 and 25 (figure 3) for monitoring the temperatures at ports 22 and 24 and that communicate with the controller 60 and or the cloud based software service. The controller uses the flow and return sensor data from sensors 23 and 25 to assess flow rate and temperatures to calculate space heating energy loads and to maintain improved control of the overall store temperature.

The controller and/or cloud based software service process records input/output data to control (in an attempt to optimize or at least improve) the store temperature through the active control of the heaters 16 and 18. The objective of the system’s controls is to maintain the lowest temperature of store 10 that meets the predicted space heating needs, subject to maintaining an optional buffer to account for possible margins of error in any of the components or minor variations in a user’s behavior or changes in the weather from the predicted weather.

During space heating operation the controller 60 and/or the cloud based software service, controls the function of circulator pump 30 and valve 32 to actively manage thermocline stratification within the store 10. For example, at the start of a space heating period, the circulator pump 30 and valve 32 may operate to circulate water between the top and the base of the store 10. This circulation encourages thermal mixing of the store and prevents thermal stagnation of cooled water from remaining in contact with the heat exchanger 20. However, at the end of a heating period, the circulator pump 30 and valve 32 may revert to a circulating to a mid-store position, thereby promoting efficient stratification of the store temperature 10. This stratification of the store 10 temperature improves utilization of the upper most part of the store temperature for the benefit of anticipated domestic hot water needs. In either case, the objective of the system controls strategy is to control the store to its lowest sustainable temperature that meets the space heating and domestic hot water needs.

Additionally the system may be connected with an external weather temperature sensor shown as item 130 in figure 5, or receive weather updates via an internet service provider.

The external weather temperature sensor is connected in communication with the controller 60 or alternatively, the controller receives weather updates from the cloud software service, either way the system is then able adjust the store temperature to ensure (within an acceptable margin of error) that the store is at the lowest possible temperature that supports the predicted space heating or hot water needs. As noted earlier the limitation of the electrical current capacity of a standard electricity supply as defined by the diameter of the cable and ratings of the main fuse or circuit breaker and meter means that it is not possible to simultaneously operate all electrical equipment within a dwelling, for example, to heat the home or charge an electric vehicle, where the combined loads of both devices would, considering other normally in use appliances push the electricity demand beyond the capacity of the supply/meter and therefore may cause the main electrical fuse to overload and fail. The inventor recognizes that different appliances may have equal weighted importance to the user, and therefore, the system is capable of providing the user with a way of prioritizing and phasing electrical appliance use within the constraints of the available electrical current. For example, the system can be configured to enable a user to interchange/time multiplex the charging of an electric vehicle and the heating of hot water, within the capacity of the meter’s safe operation.

In some embodiments the controller 60 may be associated with a battery capable of maintaining the operation of the controller in the event of a power cut. The battery may also be able to supply power to operate the pump 86 in the event of a power cut such that space heating may be maintained until such time as the store 10 becomes depleted.

The controller may include a user interface, such as a web page or smart phone app. The controller may calculate the expected energy demands of the system and warn a user if these may not be capable of being reached. It may then suggest alternative energy use patterns based on user preferences. For example if the dwelling has a resident who is frail, then space heating may be a priority and the system then suggests that potable hot water use, such as for bathing, should be limited. If the residents have indicated that they prioritize personal hygiene by way of baths or showers over room temperature, then the system may modify the operation of the space heating system to let room temperatures decline when the full heating and hot water load cannot be serviced for a period of time and remedial actions by the controller (such as increasing the store temperature) cannot sufficiently compensate for the short fall.

The hot water system is formed of several elements that combine to form a novel innovative hot water system. 1. It is thus possible to provide a potable hot water store where the energy in the store is also used to provide space heating needs.

2. Advantageously, the potable water store is provided in cooperation with a controller that enables individual users of the system to define their heating and hot water needs.

3. In use the controller acts such that the store temperature is predicted and set to the lowest temperature that matches the needs of users with lowest energy costs.

4. In operation, the system provides hot water priority, detecting the use of hot water and enabling the controller and such a controller optionally being in cooperation with a cloud based software service to control heat management of the store 10.

5. It is thus possible to provide a hot water system with a controller that continually monitors the electrical loads of the supplying electrical meter to both maximize the potential heat input to the system and prevent the supplying electrical meter from being overloaded.

Embodiments of the present disclosure can provide a system having an electrically heated hot water store in association with a controller providing dynamic energy control of space heating and domestic hot water services for users and registered users of the system. The controller may be arranged to responsive to instructions received from a web-based load and/or cost management service. This can give a user better protection from adverse weather events or sudden energy cost changes.

The thermal store is preferably formed as a store of potable water, and generally the controller is adapted to provide domestic hot water services as a priority over space heating services.

In order to provide speed of response the controller knows the maximum rated electrical capacity and dynamic electrical loads of the supplying electricity meter and uses this knowledge to safely operate electrical heaters of larger heating capacity to heat the store quickly where such heating is maintained within a maximum load of the meter/master fuse arrangement.

The present teachings may also be viewed as a potable hot water store in association with a heating and hot water system controller working in cooperation with a cloud based software service providing predictive use and pre-scheduling of individual and or group user needs based on factored store temperatures and usage patterns of registered user needs.

In the disclosed embodiments the heating and hot water system is designed to provide electrical energy resource improvement through real time monitoring and optionally smart control of the electrical current loads at the supplying electric meter. The heating and hot water system incorporates a current sensor that monitors real time dynamic electrical current loads through the supplying electrical meter. The controller is responsive to the current to protect overloading of the supplying electric meter by optimizing the switching off or phasing the switch off of the heating and hot water heat input devices. The controller, either alone or in conjunction with a cloud service, may be arranged to maximize electrical heat input during domestic hot water use. This may include using the heat input devices at their maximum permitted heating power. The controller may work in cooperation with a cloud based software service and internet enabled devices to manage electrical loads across the supplying meter so as to prevent overloading of the relevant meter.

Advantageously in use the heating and hot water system controller 60 optionally working with a cloud software service uses a power or load current sensor that measures the real-time energy loads to the enable the controller and/or cloud service to modify electrical heat input such that relatively low electricity tariff periods provide an opportunity to hold more heat energy within the store, and also when advisable to raise store temperatures prior to a relatively high tariff cost period. During periods of heating the controller may control the heaters such that the total electrical heat input capacity of the system corresponds with the maximum useable electrical current rating of the supplying electric meter’s total permissible capacity.

In some embodiments the use of current monitoring allows the provision of an electrically heated heating and hot water system incorporating a controller (which may work in conjunction with a cloud based software service), where the total heat input in kW for use with an electricity supply having a predefined maximum current would, when other electrical equipment is in use on the same supplying electricity meter, potentially exceed the maximum permissible electrical current load of the supplying electricity meter.

In some embodiments a heating and hot water system incorporating a controller (optionally with such a controller working in cooperation with a cloud software service) can provide enhanced seasonal energy efficiency by applying the appropriate, regional authority or national Government’s calculation method used to pre-determine the monthly energy needs of heating and hot water systems installed in buildings, to determine a seasonally adjusted heating and hot-water store factor, calculated as a variable set-point temperature value of the store or part thereof and where the variable set-point temperature equates to the delta T temperature ranging between the lowest and highest operational store temperature needs.

In some embodiments the electrically operated heating and hot water system is able to improve or optimise energy efficiency by scheduling and predicting seasonal hot water usage patterns by registered users of the system, and for example, adjusting for specific lifestyle requirements including but not limited to, predictable hot baths in the winter compared with higher frequency, cooler showers in the summer months.

In some embodiments the controller may act to predict electricity tariffs based on historical tariff charges. This provides an electrically operated heating and hot water system adapted to control the amount of electrically generated heat input to a heat store in response to the real time monitoring of the total in use and available electrical load on the supply meter including consideration for the in use and predictive tariffs. Furthermore the system may be arranged to predictively control the amount of electrically generated heat input to the system in response to historical electrical loads.

In some embodiments the designed kW heat input to the system is set to the maximum viable Amperage capacity of the supplying electricity meter. Thus if the meter is a 40A meter then the heaters can accept 40A optionally de-rated by a few percent. In some embodiments the heating is modulated in an on-off (bang bang) manner such that the kW rate of heat input is phased over time to achieve a required kWh need. For example, but not limited to, a 6kW immersion heater can provide 2kWh of heat input in one hour, if operated for any consecutive or non-consecutive 20 minutes in the hour. The phased heat input during a measured period of time may be adjusted or optimised to, but not limited to, the available electrical capacity of the meter, electricity tariff costs and improved energy efficiency of the system.

Some embodiments provide a heating and hot water system incorporating a potable stored water volume and controller, working in consort with, but not limited to, electric heaters, current sensors, temperature sensors, flow sensors, pressure sensors and a cloud based software service designed to improve or optimise heating and hot-water comfort levels, energy bills and useful heat input efficiency.

Although the disclosure has hitherto described a system having a single thermal store this is not a limitation, and the heating and hot water system may be modified to have multiple stores. The multiple stores may have respective and water flow sensors preferably, but not limited to, monitoring the incoming cold water supply. The sensors act to inform the system of the use of domestic hot water. In response the controller may be arranged to temporarily suspend space heating services until the hot water requirement has finished or such time that the store temperature has recovered sufficiently to recommence space heating services.

As noted before, the system includes the concept of meeting user’s needs and each user may specify their needs directly to the system. However the system may also adapt to the presence of absence of specific users. The system may include means to actively predict hot water and space heating needs by, but not limited to, the thermal imaging of people entering or leaving a building, the detection of mobile phones and wifi connections or other passive measures of calculating predictive heating and hot water needs.

The system may also educate users to the cost of their energy use and how the energy cost varies throughout the day. The controller may, via a suitable interface, inform users of changing electrical tariffs and calculate a future cost to pre-planned heating periods and hot water usage demands, thereby helping users to become more aware of their service delivery costs. The controller may also recommend alternative times for lower electrical tariff periods for preplanned heating and or hot water demands.

Preferably the system is installed in a building where the thermal insulation of the property is designed to support the maximum space heating output limits of the system as determined by the maximum electrical current rating of the supplying electricity meter. For example, but not limited to, as may be calculated by the use of EN 12831 and the use of a regional or national calculation methodology for the calculation of an energy balance between a building’s thermal efficiency and maximum heat input of the heating system in relation to the maximum electrical current loads of the supplying meter.

In embodiments which have a further heat source 92, the controller may compare the relative costs of heating using the further heat source or using the electrical heaters 16 and 18 and chose the least costly option. Thus if a gas boiler is provided as the further heat source, then this might be preferentially used when gas is cheaper than electricity. Similarly if the prevailing electricity cost is less than that of gas, then electrical heating is used. Advantageously if the cost of electricity is expected to decrease to be cheaper than that of gas within a relatively short time frame (for example up to a few hours) because, for example, of expected strong winds providing excess wind generated electricity then the controller may act to inhibit the operation of the gas boiler for a while on the expectation of electricity becoming cheaper than gas.

In some embodiments the thermal store may include a material that undergoes a phase change in the operating range of the store so as to increase the energy storage capacity of the thermal store.

It is thus possible to provide an electric heating and hot water system incorporating a controller and such a controller working in cooperation with a cloud based software service that provides a means by which to automatically, but not limited to, receive frequently changing energy tariffs and which may act to improve or to optimise the electrical heat input, store temperatures and heating and hot water services to improve efficiency and lower energy bills.

Claims

1) A method of providing at least one of space heating and potable hot water in a building or dwelling, where the building or dwelling uses electricity to provide its at least one of space heating and potable hot water, and where the building or dwelling has: a thermal store that is electrically heated and where heat from the thermal store can be used to provide hot water for the at least one of space heating and hot potable water; and a controller for controlling the electrical heating input to the thermal store, and wherein the controller is adapted to be responsive to a measurement of the current being used by the building or dwelling and a time varying energy cost in order to vary the amount of electrical energy being used to heat the thermal store to vary the energy cost.

2) A method as claimed in claim 1 where the thermal store is operable to provide heat for space heating and for potable hot water.

3) A method as claimed in claim 1 or 2 in which the amount of electrical energy used to provide the heating to the thermal store is adjustable over a plurality of non-zero values.

4) A method as claimed in any preceding claim in which the amount of electricity used to provide heating to the thermal store is adjustable up to a maximum value which substantially matches a maximum permitted current draw to the building or dwelling.

5) A method as claimed in any of claims 1 to 3 in which the amount of electricity used to provide heating to the thermal store is adjustable up to a maximum value where the maximum value is greater that 6kW and less than a maximum permitted current draw to the building or dwelling.

6) A method as claimed in any preceding claim in which the controller is informed of or learns the likely pattern of use of heating and potable hot water within the building or dwelling and schedules heating of the thermal store to reduce the energy cost. 7) A method as claimed in any preceding claim in which the controller is informed of or learns the likely pattern of energy cost variation and schedules heating of the thermal store to reduce the energy cost.

8) A method as claimed in any of the preceding claims in which the controller is adapted to be responsive to measurements of current drawn by respective devices within the dwelling and is adapted to communicate with a device or a power controller associated with the respective device to vary the power supplied to the respective device.

9) A method as claimed in any preceding claims in which users can register with the controller, and where in a user can inform the controller of their specific heating or hot water requirements.

10) A heat and/or hot water system comprising an electrically heated thermal store and a controller for controlling heating of the thermal store, wherein the controller is responsive to a measurement of the current being drawn from a supply having a nominal maximum current value, and the controller is operable to modulate the amount of current used for heating the thermal store in response to the measurement of current.

11) A system as claimed in claim 10 in which the controller is responsive to information about a time varying energy cost and is arranged to schedule heating of the thermal store to reduce operating costs of the system.

12) A system as claimed in claim 10 or 11 where the thermal store comprises a first heater for heating water in the thermal store where the first heater is an electrically powered heater.

13) A system as claimed in claim 10, 11 or 12 where the system further comprises a first heat exchanger in communication with the water in the thermal store for supplying heat from the water in the thermal store to a heat transfer medium of a space heating circuit.

14) A system as claimed in claim 12 or 13 where the first electrical heater comprises a resistive element. 15) A system as clamed in any of claims 10 to 14, further comprising a second heater for heating water in the thermal store, wherein the second heater is one of: a) a second heat exchanger adapted for connection to a heat source comprising one of a natural gas boiler, an LPG boiler, a hydrogen boiler, a mixed fuel boiler, a heat pump, a solar thermal heater; and b) a second electrical heater.

16) A system as claimed in any of claims 10 to 15 where the controller is adapted to estimate at least one of a heating demand and a hot water demand within a period of time and to heat the store to the target temperature sufficient to meet the heating and/or hot water demand within that period of time.

17) A system as claimed in claim 16 in which the period of time is one of a plurality of periods of time defined with reference to a clock or a combination of a clock and calendar.

18) A system as claimed in any of claims 10 to 17 where the thermal store is heated to a target temperature and the target temperature is calculated by the controller as a function of an expected heating and/or hot water load in response to a measurement of or predicted external temperature.

19) A system as claimed in any of claims 10 to 18 where the controller is responsive to warnings of high energy demand on an electricity supply to modify the target temperature to increase it to facilitate meeting an expected heat demand.

20) A system as claimed in any of the claims 10 to 19 where the controller’s operation is distributed between a local unit and a cloud based service.

21) A system as claimed in any of claims 10 to 20 where the controller is responsive to electricity cost and cost schedules to preferentially heat the store when electricity is less expensive. 22) A system as claimed in any of claims 10 to 21 where the controller is arranged to schedule and/or inhibit the operation of electrical loads as a function of cost or current drawn from the supply.

23) A system as claimed in any of claims 10 to 22 in which the controller is informed of or learns the likely pattern of use of heating and potable hot water within the building or dwelling and schedules heating of the thermal store to reduce the energy cost and/or in which the controller is informed of or leams the likely pattern of energy cost variation and schedules heating of the thermal store to reduce the energy cost.

24) A method of controlling an electrically operated heating and hot water system the method comprising predictively controlling the amount of electrically generated heat input to the system in response to variable electricity price tariffs and real-time electrical current loads through the supplying electricity meter.

25) A thermal store comprising a vessel for containing water, a heat exchanger passing though the vessel and at least one electrical heater controllable to provide varying levels of heat for heating water in the thermal store.

26 ) A power controller responsive to a measurement of current at a measurement node, wherein the power controller can control the amount of power being used by at least one device to adjust the current flow at the measurement node so as to keep the current at the measurement node to less than a maximum permitted value.