GB2448504A

GB2448504A - Load management controller

Info

Publication number: GB2448504A
Application number: GB0707382A
Authority: GB
Inventors: Timothy Patrick Cooper
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-17
Filing date: 2007-04-17
Publication date: 2008-10-22
Anticipated expiration: 2027-04-17
Also published as: GB2448504B; GB0707382D0

Abstract

A load management controller 3 for a household electrical installation 1, the household electrical installation comprising a main panel 5 receiving electricity from a pair of electricity supplies 7, 9 and distributing the electricity to a plurality of electrical sub-circuits 19, 21, 23, 25, 27. One of the electrical sub-circuits is an energy storage sub-circuit 19, The pair of electricity supplies comprising a grid supply 7 and a micro-generator supply 9. The load management controller comprises means to measure the electricity generated by the micro-generator supply and the electricity consumed by the household and supply any surplus electricity to the energy storage sub-circuit. The energy storage sub-circuit 19 may comprise an immersion heater 29 or a storage heating unit 31.

Description

"A Load Management Controller'

Introduction

This specification relates to a load management controller for a household electr,cal installation.

Heretofore, the vast majority of households have been provided with their electricity supply from a third party electricity provider. General speaking, the electricity provider generates the electrioty in large electricity generating stations and thereafter supplies that electricity over an electricity supply grid to their customers. There are numerous problems with this system and method of supplying electricity. First of all, typically, the consumer has a limited choice of electricity provider and in many cases the consumer will have only one electricity provider willing to provide them with their electricity needs.

This leads to monopolies or effective monopolies for the electricity providers resulting in high electncity supply costs to the Consumer. Secondly, many of the electricity generating stations operate using relatively environmentally unfriendly electricity generstion methods and the more electricity used by the consumer, the more harmful to the environment they will be. This is a particular dilemma to those consumers that are environmentally aware.

One solution that has been proposed is for individual householcis to create their own electricity supply using a micro-generator. In this specification, the term micro-generator will be understood to mean a solar photovoltaic (PV) array, a wind turbine, a water turbine, a small combined heat and power unit (CHP) or other small scale micro-generator that can be used to generate electricity in the household. Although this is often seen as a more cost effective and environmentally friendly solution in the long term, there are also problems with using micro-generators as a sole electricity supply source. The greatest problem being that the micro..generators that operate using renewable energy supplies, such as PV arrays, are not guaranteed to supply sufficient amounts of energy to S household at all times and therefore the micro-generators are typically used in conjunction with rather than replacing the grid electricity supply Furthe,inore. surplus electricity from a micro-generator that is not being used in the household will flow back through the household meter on to the grid unless steps are taken to prevent this from happening. This is undesirable because electricity that flows back to the grid is subject to distribution and transmission losses. These losses do not occur if all of the electricity generated by the micro-generator is consumed in the household. It is also uneconomical if the tariff paid for electricity exported onto the grid is less than the tariff paid for electricity imported from the grid. In certain circumstances, efforts are made to store the energy produced by the micro-genettor in large battery packs but these battery packs are expensive, cumbersome and relatively inefficient arid result in a significant amount of the electricity generated by the micro-generator being lost.

It is an object therefore of the present invention to provide a load management controller for a household electrical installation that overcomes at least some of the difficulties with the known systems and methods incorporating micro-generators. It is a further object of the present invention to provide a load management controller that causes the electricity generated from a micro-generator to be utilised in an efficient and effective manner.

Statements of Invention

According to the invention there is provided a load management controller for a household electrical installation, the household electrical installation comprising a main panel receiving electricity from a pair of electricity supplies and distributing the electricity to a plurality of electrical sub-circuits, one of which being an energy storage sub-circuit, the pair of electricity supplies comprising a grid supply arid a micro-generator supply, the load management controller comprising: a power meter to monitor the amount of electricity being supplied by the micro-generator; a power meter to monitor the amount of electricity being consumed in the household; and means to alter the amount of electricity supplied to the energy storage sub-circuit to route surplus electricity supplied by the micro-generator to the energy storage Sub-circuit.

By having such a load management controller, the electricity generated by the grid may be used to augment the power supplied by the micro-generator to ensure continuity of supply to the customer. The electricity supplied by the micro-generator is used to satisfy the electricity requirements of the household so that all of the electricity generated by the micro-generator is put to optimum use. If additional power is required by the electrical Sub-circuits, this electricity is first of all sourced from the micro-generator and only on the demand exceeding supply of the micro-generator will the additional electricity be sourced from the grid. Most importantly, if the electrical sub-circuits are drawing less electricity than that being produced by the micro-generator, the controller can alter the amount of electricity being supplied to the energy storage Sub-circuit so that the electricity generated is not wasted and is put to the most effective use possible. If the amount of electricity required by the sub-circuits should decrease further, additional electricity will be fed to the energy storage sub-circuit by the controller so that the amount of electricity being produced by the micro-generator Is balanced with the amount of electricity being put to use in the household. If the amount of electricity required by the sub-circuits should increase, the amount of electricity being fed to the energy storage sub-circuit will be reduced proportionately.

In another embodiment of the invention there is provided a load management controller in which the means to alter the amount of electricity supplied by the micro-generator to the energy storage sub-circuit comprises a thyristor. A thyristor is seen as a particularly useful device as it will allow smooth transition of the amount of power applied to the energy storage sub-circuit. A thyristor is a highly efficient solid-state semiconductor device that can be used to decrease and increase the amount of AC power passing through the device. The use of a thyristor enables the Invention to smoothly and seamlessly decrease and increase the amount of power delivered to the energy storage circuit and in doing so to ensure that the amount of power being delivered to the energy storage circuit precisely matches the amount of surplus power being generated by the micro-generator. Alternative devices such as variable resistance heaters and variable speed motors and pumps can be used in a similar fashion where circumstances permit.

In a further embodiment of the invention there is provided a load management controller in which the energy storage sub-circuit comprises an energy storage device. Preferably, the energy storage device comprises an electrical immersion.

The electrical Immersion is seen as a particularly effective device for storing the additional electricity supplied as it will satisfy in part or in total the household's heated water requirements and further can be used for a variety of purposes.

Alternatively, the energy storage device comprises a storage heating unit. In another alternative embodiment, the energy storage device comprises an electrical under floor heating unit. As further alternatives still, the energy storage device could comprise one or more of an agatype electric cooker. a swimming pool with associated temperature regulation equipment, a heat pump, a variable speed compressor in a heat pump, a fridge or a freezer.

lii another embodiment of the invention there is provided a load management controller in which the controller has means to control power to one or more of the other electrical sub-circuits. This is seen as particularly preferred as the controller may block electricity usage by other equipment if desirable or control when electricity is supplied to other electrical sub-circuits.

In one embodiment of the invention there is provided a load management controller in which the controller has means to detect occupancy of the household and Control power to one or more of the electrical sub-clituits based on the occupancy of the household. This is seen as effective as the controller may prevent electricity being supplied to certain circuits on the household being empty. For example. it may be deemed unnecessary to supply electricity to a television set, even in standby mode, when there are no occupants in a building and therefore electricity can be prevenled from being supplied to the sockets or the individual socket supplying the television when there are no occupants of the household. Similarly, electricity may be prevented from reaching certain lights when it i determined that there are no occupants of the household.

In a further embodiment of the invention there is provided a load management controller in which the controller has means to control power to one or more of the electrical sub-circuits based on the time of day. This is seen as advantageous as it may be more economical to run certain equipment such as tumble dryers or dishwashers at certain times of day, for example between 7pm and 7am to avail of preferential rates from the electricity provider or to ulilise any additional electricity from the micro-generator when demand from other more essential loads is lower than at other times of the day or night.

In another embodiment of the invention there is provided a load management controller in which the micro-generator supply comprises a solar PV array. This is seen as a particularly preferred embodiment of the invention and the solar PV array is seen as a cost effective and simple device to install, implement and maintain.

In one embodiment of the invention there is provided a load management controller in which the micro-generator supply further comprises a dedicated inve,ter/controller circuit. An inverter controller ciuit may be necessaty to convert the electricity from the micro- generator into a format useable in the household.

In a further embodiment of the Invention there is provided a load management controller in which the micro-generator supply further comprises one of a wind turbine, a water turbine and a small CHP. These are seen as useful alternatives to the solar PV array and may be useful depending on the renewable energy source available to the household and the amount of energy required by the household.

Detailed Description of the Invention

The invention will now be more clearly understood from the following description of an embodiment thereof, given by way of example only, in which:-Fig. 1 is a diagrammatic representation of a household electrical installation incorporating the load management controller according to the present invention.

Referring to the drawing, there is shown a household electrical installation, indicated generally by the reference numeral 1, incorporating a load management controller 3.

The household electrical installation 1 comprises a main panel 5 ted by a pair of electrical supplies, one of which is the grid supply 7 and the other of which is a micro-generator supply 9. The grid supply 7 is fed to the main panel 5 via an electric meter 11 and a load meter 13. The micro-generator supply 9, in this case a 3kW PV array, further comprises an inverter/controller 15 and is fed to the main panel 5 va a micro-generator meter 17 and the load meter 13.

The household electrical installation 1 further comprises a plurality of electrical sub-circuits 19, 21, 23, 25 and 27 fed from the main panel 5, one of which is an energy storage sub-circuit 19. The electrical sub-circuits include an occupancy related circuit 21 which is in turn connected to equipment such as personal computers, lighting systems, ventilation systems (not shown) and the like, a night saver-on circuit 23 which in turn is connected to equipment such as a washing machine (not shown) and the like, a night-off Circuit 25 which in turn is connected to equipment such as controls, pumps, chargers, lights (not shown) and the like, and an essential services circuit 27 which is connected to equipment such as alarms, fridges, security lights (not Shown) and the like. The energy storage sub-circuit 19 comprises an electrical immersion 29 and an electric under floor/storage heating unit 31. The energy storage sub-circuit 19 is fed from the main panel via a thyristor 33. The load management controller 3 is in communication with the thyristor 33. There are further provided a plurality of switches 35, 37 and 39 intermediate the main panel and the sub-circuits 21, 23 and 25 respectively. The load management controller is in communication with each of the switches 35, 37 and 39. Finally, an occupancy sensor, 41. in this case provided by an occupancy card switch, is provided and is in communication with the load management controller.

In use, the micro-generator supply 9 produces electricity by converting the renewable energy source, in this case sunlight, into electricity. The manner in which the micro-generator supply 9 converts the renewable energy source to electricity will be understood by those suitably skilled in the art and is considered outside the scope of the present invention as the manner of the conversion is not deemed particularly relevant to the understanding of the present invention. Once converted into electricity, the electricity is fed to the main panel from the micro-generator supply 9 via the inverter/controller 15 where the electricity is transformed into a form usable in the household, in this case 50 Hz, 240V AC. The amount of electricity generated and supplied to the main panel by the micro-generator is monitored by power meter 17. This electricity is used to power the sub-circuits 21, 23, 25 and 27 and if there is sufficient electricity remaining, energy storage circuit 19. lIthe electrical sub-circuits 21, 23, 25, 27 require more electricity, the amount of electricity fed to energy storage sub-circuit 19 is reduced and if the electricity requirements of the electrical sub-circuits 21, 23, 25 and 27 should increase so that they require more electricity than the micro-generator is producing, additional electricity is drawn from the grid supply 7 to meet that need.

It the electricity required by the electncal sub-circuits 21, 23, 25 and 27 should fall below the level of electricity being produced by the toad management controller once again, the electricity from the grid is no longer drawn by the main panel and any additional electricity not required by electrical sub-circuits 21, 23, 25 and 27 is once again fed to the energy storage sub-circuit 19. The load management controller 3, with the assistance of the thyristor 33, ensures that the electricity is delivered to the energy storage devices, namely the electrical immersion 29 and the electric under floor/storage heating unit 31 of the energy storage sub-circuit 19, in a very smooth fashion so that sudden increases or decreases in the amount of electricity are not expenenced by the energy storage sub-circuit. By providing the electricity in a smooth fashion, the device ensures that the power directed to the energy storage circuit is continuously and smoothly adjusted to match the surplus output from the micro-generator which is constantly changing because solar arid wind input, for example, and household consumption are constantly changing.

In addition to the above, the load management controller 3 is in communication with an occupancy sensor 41 and switch 35 intermediate the main panel and the electrical sub-circuit 21. In the event of the occupancy sensor 41 detecting that there are no occupants, the load management controller opens the switch 35 thereby preventing electricity being supplied to the occupancy related electrical sub-circuit 21. This reduces waste of electricity and more electricity from the microgenerator may be directed to the energy storage sub-circuit 19 is available. If the occupancy sensor should detect the presence of occupants, the switch 35 will be closed by the load management controller 3 once more. Similarly, the load management controller 3 will be in communication with the switches 37 and 39 and will be able to control the flow of electricity to the night saver-on electrical sub-circuit 23 and the night-off electrical sub-circuit 25. For ecample, the load management controller may determine that it is desirable to operate the washing machine (not shown) formng part of the night saver-on electrical sub-circuit 23 only during the hours of 7pm to 7am and the load management controller will open the switch 37, thereby preventing supply of electricity to sub-circuit 23, between 7am and 7pm and close the switch between 7pm and 7am to allow supply of electricity and operation of the washing machine. Furthermore, the load management controller can control flow of electricity to certain equipment in the night-off electrical sub-circuit 25 by opening or closing switch 39.

In this specification, the term household has been used throughout to indicate a relatively small scale structure that would potentially implement some form of renewable energy power supply. It will be understood that household is not intended to be solely limited to houses but may include other permanent or temporary structures, particularly those used as dwellings. including but not limited to apartments, flats, sports facilities including both indoor and outdoor arenas, office buildings, buildings in which businesses operate, public services buildings, hospitals, hotels, hostels, guest houses, places of worship, marquees and the like.

Furthermore, the term grid has been used to indicate not simply the national electricity Supply grid but a regular power supply which may include a non-environmentally friendly power supply such as a dedicated diesel burning power supply that may be in use in such structures. In such cases, the present invention operates by substituting the non-environmentally friendly power supply with the more environmentally friendly renewable energy power supply from the micro-generator It can be seen from the foregoing that the present invention provides the users with a highly efficient low cost means of storing surplus electricity in the form of heat, either in insulated hot water cylinders or electric storage heaters (which may be fixed to walls or laid in or on walls, floors or ceilings). In addition to the above, the present invention allows for users to switch on certain non-essential Circuits (such as those serving washing machines and the like) during periods of high output from the micro-generator The present invention is not intended to cover uninterrupted power supplies (UPS) such as diesel powered UPS and the like and it is intended that the present invention will be limited to micro-generators as hereinbefore described.

In the specification the terms comprise, comprises, comprised and comprising" and the terms Include, includes, included and including" are deemed totally interchangeable and should be afforded the widest possible interpretation.

The invention is in no way limited to the embodiments hereinbefore described which may be varied in both construction and detail within the scope of the claims. -10-

Claims

Claims 1) A load management controUer for a household electrica'

installation, the household electncal installation comprising a main panel receiving electricity from a pair of electricity supplies and distributing the electricity to a plurality of electrical sub-circuits, one of which being an energy storage sub-circuit, the pair of electricity supplies comprising a grid supply and a micro-generator supply. the load management contmller comprising: a power meter to monitor the amount of electricity beuig supplied by the micro-generator; a power meter to monitor the amount of electncity being consumed in the household; and means to alter the amount of electricity supplied to the energy storage sub-circuit to route surplus electricity supplied by the micro-generator to the energy storage sub-circuit.

2) A load management controller as claimed in claim 1 in which the means to alter the amount of electricity supplied by the micro-generator to the energy storage sub-circuit comprises a thyristor.

3) A load management controller as claimed in claim 1 or 2 in which the energy storage sub-circuit comprises an energy storage device.

4) A load management controller as claimed u-i claim 3 in which the energy storage device comprises an electilcal immersion.

5) A load management controller as claimed in claim 3 or 4 in which the energy storage device comprises a storage heating unit.

6) A load management controller as claimed in any of claims 3 to 5 in which the energy storage device comprises an electrical under floor heating unit.

7) A load management controller as claimed in any preceding claim in which the controller has means to control power to one or more of the other electrical sub-circuits.

8) A load management controller as claimed in claim 7 in which the controller has means to detect occupancy of the household and Control power to one or more of the electrical sub-circuits based on the occupancy of the household 9) A load management controller as claimed in claim 7 or 8 in which the controller has means to control power to one or more of the electrical sub-circuits based on the time of day.

10) A load management controller as claimed in any preceding claim in which the micro-generator supply comprises a solar PV array.

11) A load management controller as claimed in claim 10 in which the micro-generator supply further comprises a dedicated inverter/controller circuit.

12) A load management controller as claimed in any of claims 1 to 9 in which the micro-generator supply further comprises one of a wind turbine, a water turbine and a small CHP.