By Paul Homewood

In our discussions of the grid capacity needed for EVs, I mentioned reading that the National Grid said the extra required would be tiny, maybe 5 GW or so.

We can check, because last summer they published this year’s Future Energy Scenarios (FES).

I did a full analysis here. 

The FES does not say how much extra capacity we need for EVs on their own, but it does tell us how much we would need in a Net Zero scenario in total, ie including heat pumps and other electrification as well as cars. In essence, individual parts of the plan cannot be quantified separately as they are all an integral part of the whole.

There are four scenarios, but the one that is relevant is Consumer Transformation. System Transformation involves maximising hydrogen, and the other two speak for themselves:

And this is the key chart, showing that peak demand would rise from around 60GW to 96GW:

Clearly this is a lot more than the small increase indicated by the National Grid. It is true of course that heat pumps and other things will increase demand as well, but they all come as part of a parcel.

For instance, although it is claimed that most EV charging will take place at night, much of the surplus power at that time is already being offset by demand side response, battery storage, thermal storage, electrolysis and so on.

But even then, the assumptions used are so rose coloured as to be meaningless fantasy. Indeed, the name “Consumer Transformation” gives the game away – it assumes that human nature will change.

Let’s examine the two major areas, homes and cars.

The FES expects homeowners to upgrade to the most ambitious insulation, and only use appliances when demand is low.

And not only will people have to fork out for expensive heat pumps and insulation, they will also be expected to install thermal storage as well, so as to avoid using power at peak demand periods:

This is all utterly fanciful. Can you really expect the public to spend thousands of pounds and alter their lifestyles, just so as the National Grid can get out of the mess it has created for itself? (And, yes, that also includes turning down the thermostat!)

Then we come to electric cars.

The first assumption which sticks out like a sore thumb is that the number of cars will drop to 27.9m, from the current level of 33m.

Of the 27.9m, autonomous cars will account for 6.3m, so private ownership will drop to 21.6M:

In contrast, the Committee on Climate Change assumed there will be 46m cars in their Net Zero Plan, (which incidentally calculated peak demand would be 150GW by 2050).

The FES assumes that there will be many less second cars, and that millions will happily walk or take the bus instead. Will all of this happen, just because people want to save the planet? Human nature tells us not.

Over the years, people in Britain have become steadily richer, and unsurprisingly they want to spend that money.

Fifty years ago or so, many bought their first cars. Later on, families could afford two cars, go on foreign holidays, buy bigger houses and purchase all sorts of goods which not only consume energy but need it in manufacture.

Are they expected to give up all of these trappings of the good life, just to keep their carbon footprint down?

On top of that, EV owners are expected to meekly let the grid decide when the cars can be charged, and even take electricity back when the grid is in short supply:

This I have to say is cloud cuckoo land for the vast majority, who will continue to plug in when they get home, and unplug before the grid can get their hands on their stored power the next morning.

The only thing which might influence them is if the price of power during the day and early evening is set at a punitive level, which would not be politically acceptable.

In any event, as I have already noted, charging EVs at night will not make a whole lot of difference anyway, as the potential surplus of power at night is small.

According to FES, if smart charging is used, it only cuts EV peak demand by about 10GW. V2G (vehicle to grid) might potentially reduce peak demand by 5GW, in the unlikely event people leave their cars plugged during the day, but the shortfall would need to be made good that same night, which simply adds to demand then.

The FES reckons road transport will need about 100 TWh a year. Even if this was spread out absolutely perfectly throughout the year, it would equate to 12GW. This could just about be absorbed at night, but daytime peak demand would also rise by this much.

When you factor in the CCC’s projection of 46m cars, that 12GW would nearly double.

In any case, such a perfect spread of charging is an impossibility. Charging is bound to be a much less regular and unpredictable occurrence.

As such, the CCC’s estimate of 150GW peak demand is much more realistic than the FES vision of what might happen in a perfect world. 

Finally let’s look at how peak demand progressively rises:

Consumer Transformation naturally has the highest demand. System Transformation assumes a massive rollout of hydrogen, both for heating and transport. Leading The Way assumes everybody cuts their energy consumption to a minimum, and Steady Progression says we decarbonise very slowly.

The FES assumes that petrol/diesel cars will be banned from 2035 in the Consumer scenario. As we know that has now been brought forward. We could therefore find that peak demand could hit 80GW by the mid 2030s.

Bearing in mind that we would need more capacity to allow for de-rating, that would require at least 100GW of firm, dispatchable capacity by then. Once all of the coal power stations have closed, we will be lucky to have half that much.

But more on that tomorrow.


November 27, 2020 at 01:03PM