Is having a battery inserted into every appliance in your home the way to reduce your energy use, and at the same time can it help suppliers introduce “time of day tariffs” that will smooth out system demands and help you reduce your running costs?
Its an interesting questions and one that actually poses two questions. Will “Time of Use (ToU)” tariffs save you money? AND is it better to have a central battery in your home as opposed to individual batteries in each appliance?
Well a central battery installation requires a lot more circuitry to be installed. It not only requires the unit to be wired in parallel with your mains supply (which will require an approved electrician) but it also requires relays to be installed to ensure that there is no back feed back into the grid for safety reasons. So you will need non-return relays, transfer switches as well as isolation switches to be installed (all of which will have to comply with grid codes). Overall the cost of installing a central battery pack to meet your home demands is going to be in the region of £1000+ per kWh installed (this being an optimistic view).
Now if you can sign on to a ToU such as the Octopus Go Tariff then you can charge your central battery with cheap electricity that will allow you to discharge and use this electricity during peak times in the day. That is a saving of 9p/kWh.
Assuming you install a 6kWh battery at a cost of £6000 then over the year you will save just under £200 per year on your electricity bill. Now that is a payback of 30 years which isn’t that great. So perhaps a central battery is not the best option.
OK lets consider appliances with batteries installed. Right now you probably have a few computers in your home and a few mobile phones in your home . These devices already have batteries installed. Now its not unreasonable to assume that you use these devices for at least 8 hours per day and so roughly use 2kWh (daily). So by doing nothing more than switching to a ToU tariff you could save in the region of £65 per annum (assuming your electricity right now is the same as or more than the peak cost of Octopus’ Go tariff of 14.5p/kWh).
Now my electricity is currently costing 15p/kWh so I would save an additional 0.5p/kWh which would be equal to another £11 per annum. So all in all I could save £76 per annum. Now if I switch using a refer a friend code as provided on www.refer-a-friend.co.uk then I could possibly save another £50, so actually I could save nearer £126 per annum. Not bad considering I though I was already on the cheapest tariff for my area.
Now coming back to batteries. Its not just computers that have batteries, there are other appliances that can use batteries now such as TVs:
That is right, even a TV can have a battery. So if you are thinking about changing your TV perhaps you should consider buying one with a battery. Now an average TV will use around 200watts of electricity. If you watch TV for 8 hours a day (which some people do) then you could save an additional £52 a year on your energy bills simply charging the battery in the TV during the cheap period of the ToU tariff.
It doesn’t stop there. You can now buy lots of appliances which have batteries installed such as vacuum cleaners, fridges, lawnmowers etc. To see what is available simply jump onto Google and do a search on battery operated appliances for the home.
Now the biggest appliance in any home must be the car. On average an electric car will take around 40kWh of electricity to reach full charge (100kWh is you have a Tesla and less if you have a small car). Now if you used that car everyday, then charging the car on the cheap ToU rate will save you £1445.40 per annum as opposed to charging your car on a standard tariff. Give the cost of installing an EV charger is around £500 (including the benefit of installation grants) then the payback is less than a year for the charger.
If you consider that an average EV will travel around 50 miles on a full charge then the cost of doing a mile in an EV, which has been charged using the cheap rate on the ToU, is around 4p/mile. That is around 8p/mile cheaper than using petrol or diesel. So over the year the user of an EV will be £1,460 per annum.
So basically having batteries installed in appliances, whether TVs, Computers or Cars will save you money when you combine the use of these with Time of Use tariffs. Installing a central battery system to save money by charging during the cheap rate period and discharge during the peak rate period will save you money but it will take a long time to pay for the capital investment (nearly 30 years).
Thus a possible way to save money on your energy bills is to transfer to a ToU tariff and then charge up the batteries in their appliances during cheap periods and use these appliance during peak periods. Note the easiest way to control when appliances are charged is to simply plug them in to a smart extension lead which has an inbuilt time or wifi control.