Delivering an affordable net zero is paramount07 Oct 2021
Net zero electricity by 2035 is something we should be shooting for. Not least because we’ll need more electricity than ever before. We will need it to fuel our vehicles and heat our homes. Once we have net zero electricity, it can be an accelerant of net zero more broadly as we can use that electricity to decarbonise other parts of the economy.
And the last few weeks have made me even more convinced of the need to accelerate the transition. Boris Johnson’s reported plan to address the volatility we’ve seen in global energy markets lately by driving greater investment in indigenous sources of low-carbon energy makes sense.
Global gas prices will always be out of our control, but when it comes to building low-carbon electricity, Britain has competitive advantage. It is in the North Sea after all that we are currently building the world’s largest offshore wind farm at Dogger Bank and we have another to rival it in planning at Berwick Bank in Scottish waters. It’s significant that SSE – a UK-listed company – is now building more offshore wind than anyone else in the world.
But whilst offshore wind is the cheapest scaleable technology and the key to an affordable energy system, we know there will be days when the wind isn’t blowing. So it’s a big part of the answer, but it’s not the whole answer.
Some will argue for one technology over others as if there is a silver bullet. The reality, as with everything in life, is that diversity and flexibility will be needed to enable a secure, low-carbon electricity system at affordable prices. A recent report we commissioned from economists LCP laid this bare – identifying potential savings of almost £50bn by 2050 through getting this mix right.
Nuclear as always gets the headlines. And it is definitely part of the solution. It provides low-carbon baseload and that’s useful for the system up to a point. But it’s expensive and inflexible to turn on and off so does not complement cheaper renewables. It also creates a long-term waste issue. So it’s part of the remedy but the dosage should be moderate. Indeed a good chunk of the potential savings LCP identified come from avoiding building nuclear.
Flexibility is what really matters in a renewables-led system. And the technologies needed to provide this flexibility are already out there. Take pumped hydro storage, for example. It complements cheap intermittent energy sources beautifully – when it’s windy and there is excess electricity, rather than turning this off, the output can be used to pump water up to a reservoir, where it stays until wind output is lower and the power is needed to help balance the system. It essentially uses water and gravity to create a natural battery. LCP found that building more long duration storage of this kind could save 5bn of system costs by 2050. We need to get on with building it; however, even then there are only a handful of sites, so it isn’t the full answer.
Hydrogen can play a similar role, with excess electricity on windy days being used to split water into oxygen and hydrogen via electrolysers and then used for generating power by burning the hydrogen when it is needed, alongside other uses in heating, heavy goods vehicles and industrial processes. But this is earlier stage technology meaning more investment will be needed before we can deploy at scale.
Carbon capture and storage technologies fitted to gas power stations will provide a very flexible back up to wind and it’s encouraging that the Government process for supporting these projects via industrial clusters is continuing at pace. LCP’s analysis showed CCS could offer £7bn of savings by 2050 versus building less flexible nuclear.
At a smaller scale, batteries can also play a part in a more flexible and decentralised energy system in the future. They provide great flexibility, but can only generate for just a few hours so there are limitations, too. And then there’s the demand side. Greater responsiveness among electricity users, particularly large industrial ones, in dialling up or down their consumption at certain times definitely has a part to play, too. Electric vehicles in particular can be used as batteries to help smooth out peaks and troughs.
LCP also found that deploying more offshore renewables than planned and optimising the electricity market rules to keep existing renewables running longer could save over £25bn to 2050, so the Prime Minister is right to increase the renewable energy push.
Net zero will be renewables-led all round the world and in the UK we have a fantastic opportunity with offshore wind. But it must be pursued in parallel with technologies that provide the flexibility needed to balance their inherent variability cost-effectively or we’ll end up spending more than we need to – and clearly affordability is paramount if we’re to maintain public support for net zero.