Tony Onodi's Blog

Does Labour's New Energy Plan Add Up?

Labour have given us a glimpse into the Milliverse ahead of their conference this week by announcing an energy plan that they say will replace fossil fuels with renewables and nuclear power for grid electricity by 2030. They plan to "double the amount of onshore wind, triple solar and more than quadruple offshore wind power" to achieve this (while remaining curiously silent on nuclear power, and even energy storage). This is all a bit vague right now, and hopefully we'll get some better numbers as the conference wears on, but based on what we know do these numbers add up?

In 2021 the UK generated 4,605kWh of electricity per person, or about 310TWh in total. Given that the green energy transition is going to require that we electrify heating, most transport, and as many industrial processes as possible by 2050 we should take this as a bare minimum target. Using data from the Wikipedia pages for wind, solar, and nuclear in the UK (and by doing some fudging where I pretend 2020, 2021, and 2022 are the same year) I think our current green energy situation looks something like this:

Installed capacityCapacity factorAnnual generation
Onshore Wind14.43 GW23%29 TWh
Offshore Wind11.3 GW37%36.5 TWh
Solar13.78 GW11%13.3 TWh
Nuclear9.15 GW63%50.5 TWh
Total129.5 TWh

If we assume nuclear stays the same (which it won't unless planned shutdowns of our current fleet are cancelled) then Labour probably wants our energy situation to look like this by 2030:

Installed capacityCapacity factorAnnual generation
Onshore Wind28.86 GW23%58.2 TWh
Offshore Wind45.2 GW37%146.6 TWh
Solar41.34 GW11%39.9 TWh
Nuclear9.15 GW63%50.5 TWh
Total295 TWh

So not quite enough.

Making Up the Difference

Our very crudely calculated total generation of 295TWh brings us 95% of the way to our bare minimum target. Given the excruciatingly slow process of financing, approving, and building new nuclear power plants, and the fact that a lot of our current nuclear power plants are scheduled to be shut down by 2030 I find it very unlikely the missing 15TWh will be made up by nuclear power. If anything, our nuclear power projections are far too optimistic.

If Xlinks, a promising looking plan to import up to 7.5% of the UK's electricity from Morocco via the world's longest undersea interconnector, is both started and finished by 2030 then, on paper at least, that could make up the difference. Unfortunately I can't say I know enough about this project to know how likely that is.

Finally Labour have given themselves some wiggle room by saying that they intend to "more than quadruple" offshore wind. The UK has 1,800GW of offshore wind potential, so really you can be arbitrarily optimistic with your interpretation of "more than" until all of our energy problems are solved! But if we stay relatively sensible with our interpretation and assume Labour intend to 4.5x our offshore wind that gives us an extra 18.25 TWh of energy per year.

Currently we generate about 5TWh of energy annually from run-of-river (i.e. not pumped hydro storage) hydroelectric power stations, this seems unlikely to change significantly in either direction, so it certainly helps.

So a more optimistic reading might look like this:

Installed capacityCapacity factorAnnual generation
Onshore Wind28.86 GW23%58.2 TWh
Offshore Wind50.9 GW37%164.9 TWh
Solar41.34 GW0.11%39.9 TWh
Nuclear9.15 GW0.63%50.5 TWh
Hydroelectric1.87 GW5 TWh
XLinks23.25 TWh
Total341.8 TWh

The UK also gets a non-trivial amount of energy from landfill and sewage biogas (disgusting, but probably good) and biomass (less disgusting, but probably bad). But solid numbers on these are harder to come by, and I think I've already shown that—with very crude accounting at least—there might be enough energy generation to go around.

So Is It Really That Simple?

No. Labours targets for installed capacity seem ambitious but just about plausible. Between 2020 and 2021 the UK added about 8.5% to its offshore wind capacity, to quadruple offshore wind by 2030 this growth rate would need to, starting from this year, average 18%! That's a huge growth rate, but might not be completely impossible, especially given the Conservatives under Truss have indicated they intend to increase renewable installations.

As always with renewables the thorniest problem isn't capacity, or even cost any more, but intermittency. Labour's plan might provide more energy than we need for the year, but sometimes too much of this will arrive at the same time, resulting in curtailment. Other times not enough will arrive (pleasingly, we call this dunkelflaute) resulting, realistically, in us burning gas in peaker plants. We can smooth out some of this with grid energy storage, mostly pumped hydroelectric, and lithium ion batteries. But dunkelflaute can last for days, or even weeks, on end and neither batteries nor pumped hydro can economically store energy for that long.

I don't think any energy plan can get us to a fully renewable grid by 2030. David Osmond simulated the past year of renewable generation in Australia, imagining that they'd rolled out a big increase in renewables, and still only managed to get to a 99% renewable grid. He thinks Australia had a particularly good year too, and in a more normal year they'd be more likely to only hit 98%. Compared to the UK, Australia's per capita space, sun, and wind is laughably abundant. We'd be lucky to do as well as this any time soon.

Politically, it's a little alarming that Labour have set themselves up for failure like this. Even if they get us to a 95% renewable grid by 2030 that would be a remarkable achievement, but would still be a failure on the terms they've set out. It's possible they'll refine their position soon, they might adjust the target down a bit from 100%, or say they'll offset the remaining carbon in some way, but I still think it's a strange trap to set for yourself.

Practically, on the other hand, I think this policy is excellent. If we build a >95% renewable grid by 2030 we can spend the following 20 years expanding the grid further, moving as much of our energy consumption onto it as possible, and making up the last 5%. Because of the non-linear effect of intermittency it's still not entirely clear to me just what percentage of grid generation we can expect this renewables roll out to cover. Earlier this year I wrote a post about how I simulated renewables generation and storage for the UK grid. I intend to use the same techniques to model Labour's plan soon, so follow me on twitter if you'd like to find out when that's done, and tweet me if you have any comments about this post.