The Royal Society, Britain’s oldest scientific academy, has called on the government to kick-start the construction of large-scale hydrogen storage facilities to meet its 2035 net zero target for a zero-carbon electricity network.
The report, Large scale electricity storage, published by The Royal Society today (11 September), looks at ways to store surplus renewable electricity such as green hydrogen, compressed air energy storage, ammonia and heat. These technologies will be needed to provide flexibility when the GB electricity supply is dominated by intermittent renewables.
“Storing most of the surplus as hydrogen, in salt caverns, would be the cheapest way of doing this,” The Royal Society says.
The report is based on 37 years of weather data and finds that by 2050, 100TWh of storage will be needed, about a quarter of the UK’s current annual electricity demand.
“This would be equivalent to more than 5,000 Dinorwig pumped hydroelectric dams. Storage on this scale, which would require up to 90 clusters of 10 caverns, is not possible with batteries or pumped hydro,” The Royal Society notes.
This level of requirement is more than currently foreseen by the government, and work on constructing these caverns should begin immediately to meet net zero targets, the report says.
Sir Chris Llewellyn Smith FRS, lead author of the report, said: “The need for long-term storage has been seriously underestimated. Demand for electricity is expected to double by 2050 with the electrification of heat, transport, and industrial processing, as well as increases in the use of air conditioning, economic growth, and changes in population. It will mainly be met by wind and solar. They are the cheapest forms of low-carbon electricity generation, but are volatile – wind varies on a decadal timescale, so will have to be complemented by large scale supply from energy storage or other sources”.
The only other large-scale low-carbon sources are nuclear, gas with carbon capture and storage (CCS), and bioenergy without or with CCS (BECCS). While nuclear and gas with CCS are expected to play a role, they are expensive, especially if operated flexibly.
Sir Peter Bruce, vice-president of the Royal Society, said: “Ensuring our future electricity supply remains reliable and resilient will be crucial for our future prosperity and wellbeing. An electricity system with significant wind and solar generation is likely to offer the lowest cost electricity but it is essential to have large-scale energy stores that can be accessed quickly to ensure GB’s energy security and sovereignty.”
According to the Royal Society, ”there are currently three hydrogen storage caverns in the UK, which have been in use since 1972, and the British Geological Survey has identified the geology for ample storage capacity in Cheshire, Wessex and East Yorkshire. Appropriate, novel business models and market structures will be needed to encourage construction of the large number of additional caverns that will be needed, the report says.”
Llewellyn Smith believes that Britain could in principle be powered solely by wind and solar, supported by hydrogen, and some small-scale storage provided by batteries.