EV Power Scenarios

By Paul Homewood

There has been a lot of debate about the additional electricity demands which electric cars will impose on the grid.

A figure of an extra 30GW has been widely reported, but this is reckoned to be the maximum likely. The Telegraph printed this letter on Sunday from Richard Black’s global warming propaganda unit, the ECIU:

SIR – Gordon Rayner and Steven Swinford are prudent to outline some of the challenges facing all nations as the electric vehicle revolution takes hold, but claims that peak electricity demand will jump by 50 per cent and that we will need to build 10,000 new wind turbines are wide of the mark. These figures represent National Grid scenarios which are exceedingly unlikely to come to fruition, and should not be used to discourage change that will be driven by the market as much as by government policy.

Other forecasts show that the increase in peak demand could be less than 10 per cent – a figure that is more than capable of being managed by a burgeoning British technology sector. The benefits that 26 million electric vehicle batteries could offer the UK grid are also startling, increasing the democratisation of energy supply and allowing homes up and down the country to take back control of their energy bills.

Dr Jonathan Marshall
Energy Analyst, Energy and Climate Intelligence Unit
London SE1

This letter is even more misleading than the claims of 30GW.

So let’s start from scratch. The chart at the top, from the National Grid’s latest Future Energy Scenarios (FES), shows that the “10%” figure claimed by Marshall is based around the highly optimistic “Two Degrees” scenario.

In particular, it assumes that drivers will only charge cars at off peak.

Yet as another recent National Grid study found, this is not a realistic option. Millions of cars have no access to off road parking, and many that do have no garage access. For these owners, overnight charging is not practical.

For these, the only logical option is to use public charging stations. This will inevitably put huge extra demand onto periods, such as early evening, when demand already peaks.

Readers may recall that the FES contained four scenarios, and it is the “Consumer Power” one which best fits this behaviour:

Under this scenario, peak demand increases by 17.7GW in 2050, an increase of about 28% on current demand, and a lot more than the ECIU’s claim.

But there is another scenario that is hidden away, called “High Electric Vehicles”

This, rather presciently, is pretty much what the government is now proposing.

But to backtrack, this is what the FES says about the number of cars on the road for the first four scenarios:

http://ift.tt/2urkWao

Note that under the Two Degree scenario, the number of cars drops sharply from current levels.

Also under the Consumer Power option, there are still nearly 10 million non EVs on the road in 2050. The government has already stated its intention that all cars must be zero emission by then.

Now we can add in the High EV scenario:

Assuming that car ownership stays constant as a percentage of population, there will be 9 million more EVs by 2050 than the Two Degree scenario suggests, and 12 million more then the Consumer Power option.

And this is what the High EV outlook does for peak demand.

Demand will rise by 30.6GW from current levels.

The FES also notes that only 20% of cars will be charged at peak time. This sounds extremely optimistic, given that 43% of households have no access to off street parking.

Nobody can forecast the future, but it seems to me that the High EV figures are likely to be much nearer the truth than the rest.

FOOTNOTE

Last week I made a very simplistic, back of the fag packet guess on the extra electricity needed, if all cars were EV. I came to an annual figure of 112 TWh.

The FES concludes it will be 90 TWH, so I was not far out!