Storing hydrogen deep underground in salt caverns could help the UK meet peak energy demands, according to a new report by the Energy Technologies Institute (ETI).
The report, written by the ETI’s Carbon Capture and Storage (CCS) strategy manager Den Gammer, said that these stores of hydrogen could be converted into a reliable, affordable and flexible power source when required – potentially reducing the investment needed to build new power stations.
Salt caverns are already used for storing oil and natural gas. In the UK there are around 30 very large caverns which store natural gas for the power and heating market. A single cavern filled with hydrogen could cater for the peak demands and demand fluctuations of a whole city, according to the ETI report.
The UK’s energy landscape is changing very rapidly. More renewable power supplies are being installed and, although clean, these new supplies are intermittent, which increases the need for a low-cost, clean, on-demand power supply that currently only fossil fuel plants can provide, Gammer said.
The country needs a system that follows the load the public creates and our research shows that systems involving the storage of hydrogen and creating power from it, can do that in a very flexible way. Modelling shows that such storage schemes become effective in the time period 2030-2040.
Looking at the UK’s future energy requirements, the ETI believes that fossil fuels will still have a role to play beyond 2030 but says that those plants should be equipped with CCS technology. As well as providing low carbon electricity, CCS can capture emissions from industry, help deliver low carbon gas and offer the benefit of ‘negative emissions’ when combined with bio-energy, it said.
Gammer added: Beyond 2030, to get the most out of the investment required for installing a CCS plant you would need to reduce the time it is spent idle because its power production may not be required. If you can store hydrogen that is produced continuously by modestly sized hydrogen plants in salt caverns, then you release that to generate electricity only when the system demands it.
This is a lot more efficient and cost-effective than building a whole new power station designed to meet peak demand but only running for a small part of the day.