The WrightChoice Heat Storage Device gives you everything you need to store energy in an existing home with a simple low cost retrofit device which will allow you to store surplus energy at night. You can also use that stored energy to reduce your energy use at peak times. It is a win-win, as when there is energy surplus on the grid you can soak up that energy and store it in your home. During peak demand periods you can reduce your energy demand. This happens throughout the year.
This is only possible if you already have a hot water cylinder, and in the UK 70% of homes have Combi Boilers. For those 70% unfortunate enough to have Combi Boilers and electric showers, there will be the additional capital cost of adding a hot water cylinder.
My Radiator Flow Boosters which I have sold for 3 years have proven the technology which makes it possible to add a hot water cylinder to help those with combi boilers for washing and bathing.
A separate hot water tank for central heating water (with inhibitors), and holding the non-potable water for central heating systems is needed in order to replace gas or oil central heating with 100% renewable energy sources in a home. Central heating uses far more energy than that used in heating water for washing and bathing, and the power grid may not be sufficient to totally replace fossil fuel with renewables.
We sell the devices to achieve hot water storage and to integrate any water heat store with any demand use. To download our company brochure with our full range of products – Old Favourites and New Innovations – click on this link:-
https://showerpowerbooster.co.uk/wp-content/uploads/2023/11/FlowflexShowerManual_30_11_23-NEW.pdf
Why there is excess energy at night
There is surplus energy at night especially when the wind blows and there is always little demand.
There is always surplus energy even when the wind does not blow because demand during a 24 hour days fluctuates.
How to store that spare energy
Storing energy in Lithium-Ion batteries is expensive, and whilst my 13.5 KW/Hr Tesla Power Wall costing £10,000 in my own home stores enough electrical power for 24 hours normal non central heating demand, it only stores enough energy to replace my 24 KW gas boiler for 30 minutes. You would need 15 Tesla Power Walls to replace my gas boiler. My 500 litre hot water cylinder does a bit better storing up to 13.5 KW/Hr and costing £500, but that provides hot water for washing and bathing so that’s not really available for central heating (although I do use part of its capacity now for a separate potable water central heating loop using one of my Radiator Flow Boosters controlled by an Anglian Electronics operating system).
Storage of energy in water offers a very cheap and simple method to store energy. Once you fill the water tank you need no further water to be added. A 24 KW gas boiler running for 8 hours uses 192 kilowatt hours and we can easily store 200 kilowatt hours of energy in 4,000 litres of water.
Practical Problems to Consider
Weight of Tanks – 1,000 litres of water weighs 1 tonne
The tanks are empty when installed, filled with water when commissioned, and for new build, a single 4,000 litre tank, or multiple large tanks installed under the floor slab of a new home, saves space, and is the logical solution.
Size is a problem for retrofit. I have retrofitted a 500 litre copper cylinder upstairs above a structural wall. A bigger tank might have been practical if it were installed on the ground floor. Perhaps 1,000 litres is the maximum size for a residential retrofit but for reasons of power supply to that tank a smaller unit may be desirable.
Plastic, Copper, or Steel Tanks
Whilst plastic tanks will deal with the temperatures needed, (and I have used them before), I suggest that any retrofit solution should use traditional copper or steel hot water cylinders. The UK has a mix of vented and unvented plumbing systems and the tank manufacturers use steel cylinders for unvented systems, and copper cylinders for vented systems.
Power Supply
The cheap rate electricity is only available within a window of time. In our home we can buy electricity at 7.5p per KW hour between 23.30 and 05.00. For the rest of the time it is x4 the cost. Taking a high demand in a 6-hour window might need expensive changes to the electrical supply in my home. Taking the power over a longer period would increase the cost of electricity. For new build it is economic to provide an uprated power supply and for a large tank to have multiple immersion heaters. Uprating a power supply in an existing home can be expensive. This can be avoided by using smaller tanks and standard 3 KW hour immersion heaters.
Insulation.
An insulated tank is adequate if the tank is within a home. I already have a factory-insulated 500 litre hot water cylinder with just factory applied insulation to the outside of the cylinder in my own home and the heat loss is minimal.
For tanks in an outside enclosure (eg a garage), each tank will benefit from an additional hot box.
A hot box is a fabricated 4 sided surround which is filled with insulation.
I suggest using shredded and compacted recycled paper as an insulation material because it performs better than glass wool, and is simple, cheap, and highly effective.
Economic Savings To Individuals
At night the excess energy from wind farms on windy nights cannot be used to benefit customers and wind farms are paid by energy companies not to generate electricity. As an employee of Anglian Water I was aware that Anglian Water were running pumping stations inefficiently in order to qualify for cheaper energy overall. I suspect that other industrial users burn off excess electricity.
Consumers are offered electricity at low off-peak rates no cheaper than the price of gas. For new build the savings in not providing boilers and gas mains would make off-peak storage solutions cheaper than gas or oil.
Economic Savings To the Nation
The National Grid is designed for peak electricity demand in winter so some increased demand at off-peak times has no impact on the capacity of the national grid. Reducing demand at peak times will reduce the stress on the national grid and avoid the need for some further investment. For new build it can avoid laying new gas mains and reduce the strain on the existing gas pipeline network.
In my rain water harvesting I use one tonne tanks which are often spare after use in manufacturing and can cost up to £50 each (when I worked for Anglian Water as a civil engineer I buried similar tanks underground encased in concrete.)
4 number WrightChoice Heat Devices convert a one tonne tote into a heat store.
4 number Radiator Flow Boosters will feed heated water through a heat loop supplying hot water to the radiator circulatory pump in controlled quantity.
How to Get The Hot Water Around The Home.
Use a traditional radiator system and a traditional central heating pump or underfloor heating.
Create a ‘heat loop’ to inject variable quantities of hot water into the primary central heating loop.
(This sounds complicated but it is easy and proven in my own home.)
