Long-duration Energy Storage (Science and Technology Committee Report)

Lord Krebs Excerpts

Thursday 9th January 2025 Lords Chamber

[Lord Krebs (CB)]

My Lords, I had the privilege of serving on the Select Committee during much of the period of preparation of this report, and I join others in thanking our excellent chair, my noble friend Lady Brown of Cambridge, as well as thanking her for her outstanding introduction to this debate. I also thank the staff of the Select Committee, who, along with the specialist adviser, provided us with such excellent support. I join others in welcoming the Minister for her first outing at the Dispatch Box and I look forward to hearing her maiden speech. I should declare a relevant interest: that I am chair of the independent advisory board of Drax power, which generates electricity through burning biomass, and I advise it on sustainability of biomass.

I think nearly everybody agrees that we will need long-duration energy storage to cope with the intermittency in renewables, as we have already heard. Therefore, the questions really are how much we need, what technologies we will use to generate long-duration energy storage and how it will be funded. Let me talk about the first of these. To estimate how much long-term storage will be needed, we need to know how frequently and for what duration these periods of cloudy, still weather will occur. Different experts who presented evidence to the committee took different approaches to attempting to answer this question. The Climate Change Committee for example, along with the National Infrastructure Commission, as the noble Baroness, Lady Neville-Jones, has already said, used an analysis of year-to-year variation as well seasonal variation based on a combination of data and climate models. On the other hand, the Royal Society modelled a long sequence—it happened to be 37 years—arguing that wind and sun can vary on not just year-to-year timescales but decadal timescales.

If the Royal Society is correct, the amount of long-duration energy storage required will have to take into account those long-duration fluctuations, and this may in part explain why its analysis suggests the need for a much larger strategic reserve than indicated by some of the other analyses. The Royal Society concludes that the total amount of storage needed by 2050 may be as much as 100 terawatt hours. This would be equivalent to 5,000 Dinorwig pumped hydroelectric dams, or 50 clusters of 10 caverns for hydrogen. My question to the Minister is this. Do the Government agree with the Royal Society’s conclusion that plans for long-duration energy storage should reflect decadal-scale variations in renewable generation and not just interannual or seasonal variation?

I now turn to funding long-duration energy storage. The Government have said that they will introduce a cap and floor to give investors the security of a guaranteed minimum return while protecting consumers from excessive price rises, and this is in line with our recommendation. However, as has already been said by others, we also conclude that a commercially viable cap and floor funding arrangement would incentivise businesses to sell their stores rather than to keep them for events that might occur only once every 30 years. Can the Minister therefore tell us whether the Government plan to pay for a strategic reserve of energy storage not driven by short-term commercial incentives?

While the Government have not yet stated explicitly how much LDES they think they will require by 2050, the 13 December action plan, which has already been referred to, refers to 4 to 6 gigawatts of long-duration energy storage by 2030, out of the 40 to 50 gigawatts of dispatchable power needed. The rest will come, as has already been said, from gas, biomass and nuclear. I add in parenthesis that the evidence we heard regarding the amount of storage needed was expressed by some witnesses in terms of power—gigawatts—and by others in terms of energy, terawatt hours.

The Government’s action plan for clean power by 2030 is comprehensive, but I end by asking the Minister whether she could expand on the section on long-duration energy storage by giving us a little more detail about the longer-term future. First, what is the Government’s estimate of the need for LDES, both by 2035 and by 2050, and is there a road map beyond 2030 for achieving this—apart from the use of unabated gas, as suggested on page 117 of the action plan?

Secondly, what is the envisaged mix of different technologies in LDES? Page 116 of the action plan refers to nascent technologies such as liquid air and flow batteries. Is there also a role for hydrogen?

Thirdly, if, as our report recommends, hydrogen storage is going to be a significant part of LDES, have the Government decided whereabouts in the country these storage caverns are going to be located? Moreover, as my noble friend Lady Neuberger has already mentioned, have the Government considered how to engage with local communities to consider the acceptability of having large amounts of hydrogen stored under their homes?