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IET’s response to the Environment and Climate Change Committees ‘Dunkelflaute and the risks of electricity intermittency’ inquiry

The IET welcomes the Committee's inquiry into Dunkelflaute events, recognising that prolonged periods of low wind and solar generation are not rare anomalies but expected features of the UK's climate. However, no single technology can provide a complete solution to Dunkelflaute risks. Instead, the UK will require a balanced portfolio of measures, including long-duration energy storage, firm low-carbon generation, interconnection, demand-side flexibility and dispatchable power. In the near term, existing gas-fired generation is expected to remain essential to maintaining security of supply during prolonged system stress events.

Key recommendations include:

  1. Maintain a portfolio approach to resilience, rather than relying on any single technology or solution.
  2. Retain sufficient dispatchable generation capacity, including existing gas-fired power stations, until viable low-carbon alternatives are available at scale.
  3. Accelerate investment in long-duration energy storage and low-carbon dispatchable power, while recognising that many technologies remain commercially immature and are unlikely to deploy at scale before the 2030s.
  4. Reform planning and consenting processes to enable faster delivery of critical network infrastructure and grid reinforcements.
  5. Provide clear and consistent definitions for energy storage technologies to improve policy certainty and investor confidence.
  6. Introduce stronger market incentives and resilience-focused policy mechanisms to support investment in strategic reserves, long-duration storage and other security-of-supply assets.
  7. Adopt a whole-system resilience approach that explicitly tests future energy pathways against severe but credible stress events, including prolonged Dunkelflaute periods.
  8. Strengthen international cooperation while prioritising domestic energy resilience, recognising that neighbouring countries may face similar supply constraints during widespread weather events.