The UK government says it wants all new cars and taxis to be electric by 2040 and the doom-mongers have come out in force. They say that 100% EVs this will strain the UK capacity to produce electricity.

This is not correct.

Let’s put a few numbers around the question of how and when electric cars will take over from petrol and diesel and what the impact will be.

How much annual demand will 100% EVs add to UK electricity demand?

1, A 2017 electric car will typically get 4 miles from a kilowatt hour of energy. The average car in the UK travels about 8,000 miles a year. That means that a typical electric car will use about 2,000 kWh a year.

2, In 2016 there were 36.7 million cars on the road in the UK. The total amount of energy required to power these cars if they were all electric would be about 75 TWh a year. (A terawatt hour is a billion kilowatt hours).

3, The total consumption of electricity in the UK last year was about 300 TWh. So if all car and taxi transport was by electric vehicles, the total amount of electricity needed would rise by approximately 20%.

Can the UK accommodate this?

4, If all the vehicle charging in the UK was done in the hour of electricity demand from 6 to 7pm each night, then the total electricity demand in that hour would rise by just over 200 GW, or four times today’s highest power demand. This would not be possible.

5, Instead, the charging will be largely done at night. This will be encouraged by the measures the government will put in place to encourage off-peak charging. If 60% of charging occurred at night, when electricity demand falls and wholesale energy prices tend to be lower, then the increment to electricity demand will be about 15 GW (120 GWh over 8 hours). On average, winter nighttime electricity demand runs at at about 16 GW below the daily 16.00-19.00 peak. In other words, if users are incentivised to charge their vehicles overnight, demand will be essentially flat between 22.00 and 06.00. This is good outcome.

6, Between now and 2030, the UK will add about 25 GW of offshore wind. Typically, these turbines will produce at about 50% capacity factor. (This is higher than 40%+ experienced at the moment as turbines get taller, more efficient and sited in higher wind locations). These turbines will thus produce about 110 TWh a year of electricity. (25 GW *50% * 8760 hours). Offshore wind load factors tend to be highest in winter, when power demand is also high. The annual electricity demand from 100% electric cars (75 TWh) will be just under about 2/3 of the amount of power produced by the offshore wind installed from now until 2030.

7, Digital technology is proceeding fast. Within a few years, the rate of EV charging at any moment across the country will be automatically adjusted to help match overall supply and demand. Not only can EV electricity needs be easily met, properly engineered control systems will mean that charging will help stabilise the electricity system, not the reverse.