UK Research and Innovation (UKRI) launched the Ultra-Long Duration Energy Storage (Ultra-LDES) Challenge on 20 August 2026 to strengthen national energy security and shield households from price spikes, according to a press release. Backed by £28 million from government through UKRI, the initiative invites UK innovators to bid for grants to develop projects capable of supplying clean electricity for 100 hours or more. That is enough to power homes and businesses for at least four days. The challenge targets advanced batteries and underground hydrogen storage. It aims to reduce reliance on more expensive sources of power.
Wind and solar are currently the cheapest ways to generate electricity in the UK, but intermittent supply forces the grid to rely on other options, including gas-fired generation. Reducing reliance on natural gas is expected to bolster energy security. The gas system will still play an important role for decades to come, according to the source. Improved energy storage is described as a vital part of the transition to clean, homegrown energy. Laying the foundations for this move is also framed as vital in addressing the climate crisis.
The challenge focuses on two main areas. The first is the development of new battery technologies capable of providing energy for over 100 hours, electrochemical technologies that are yet to be commercialised at scale. The second supports the development and testing of systems that store hydrogen underground and release it when needed. Underground hydrogen storage holds the potential to reduce total energy system costs by between £14 billion and £50 billion between 2035 and 2050. UKRI has also launched a competition offering up to £3 million to fund studies into electrochemical ultra-long duration energy storage technologies.
Science Minister Chris McDonald linked the initiative to wider benefits from research and innovation. “When we unlock the potential of science and innovation, it can improve all of our lives,” he said, adding that meeting the challenge of storing energy from renewables would improve energy security and bring down bills long-term. Energy Minister Michael Shanks said homegrown clean energy is the route to more affordable bills and energy security. Jenny Hill, UKRI’s Clean Energy Challenge Director, said the challenge will help propel the UK to the forefront of the global energy storage market. Clare Jackson, CEO of Hydrogen UK, called ultra-long duration energy storage critical for moving to a more secure, low-carbon energy system.
The launch completes the roll out of the £102 million clean energy challenges, which include the Ultra-LDES challenge and the £74 million consumer-led flexibility challenge. The Ultra-LDES Challenge sits within the R&D Missions Accelerator Programme, investing at least £500 million by 2030 into research and development. The programme targets one to two demonstrators of long duration energy storage systems over 100 MWh by 2030 and deployment on the grid at GWh scale by 2035. The consumer-led flexibility challenge was previously announced on 7 August 2025 with initial funding of £4 million. Further challenges are expected to be launched this year.