Your EV Tariff Could Power Your Entire House

The majority of the public, with the exception of my “Muppet” mate Bobby, seem to have grasped that EVs offer a lower cost per mile, but only 2% of the population have switched to Day/Night tariffs to bring their driving costs down to an incredibly low 2p, compared with the 17p it costs to drive petrol cars.

Yes, you read that right: 2p, a massive 88% cut!

Just as 6 years ago I launched myself into a drive to move drivers towards EVs with the creation of ECO, the Electric Car Organisation, I am now taking the next step and launching Household Energy Solutions, an independent consultancy that will guide homeowners on how to optimise their energy usage when they have an EV.

Now, most readers would expect me to start evangelising about solar panels, but actually your first step should always be to put 20, 40, or even 50 kWh batteries in your garage to take advantage of the low night rate you use to charge your EV, storing electricity for use during the day instead of expensive electricity from the grid.

The maths is complex but compelling!

The average EV driver travelling 12,000 miles a year uses about 3,400 kWh of electricity, assuming the car achieves around 3.5 miles per kWh. Charging that car at a normal daytime rate of about 29p per kWh could cost close to £1,000 a year, but switching to an EV tariff with overnight rates of around 8p could reduce that cost by a further £850.

The tariff switch itself is therefore a complete no-brainer in its own right. However, there is a sting in the tail: most EV tariffs, like Octopus, are a bit of a con because they recover the low overnight price by charging a higher rate for electricity used by the house during the day.

So although you could save £700 by charging the car, you will then give part of it back through higher household electricity bills.

The solution, however, is simple, and household energy advice can tell you how to implement it quickly and cheaply.

You just install a 20-kWh household battery, charge it alongside the EV during the cheap overnight window and use the stored electricity to power the house during the expensive daytime period. In effect, you extend the night tariff across the entire day and protect the household from the tariff’s higher daytime rate.

For a larger house using 14,000 kWh of electricity annually, the 20-kWh battery will not cover all household consumption, but it could shift up to 7,300 kWh a year from the daytime rate to the cheaper overnight rate, delivering an additional £1,500 in savings, with a 4.5-year payback and a battery you can move with you if you ever move house.

UK Energy Solutions are also investigating “Asset Based” finance to allow users to install batteries for “Free” and still cut daytime electricity costs to 21p, delivering a 25% reduction in cost whilst the remaining saving pays the capital and interest cost.

And who says no to something that costs nothing and gives you a 25% saving!

My aim over the next 10 years is to create a “Virtual Power” station of 100,000 homes that could store 637 GW, or 10% of the 1,800 GW of wind power this country wastes every year, simply because the wind blows all day and night, but our night-time electricity use is not high enough to absorb it.

Interestingly, because the savings are so large, taxpayers would not need to pay a penny in subsidies, but the Government could accelerate my program dramatically by providing the £950m of capital required at a low interest rate, as this would represent a true private/Government collaboration.

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