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Consultation on Long Duration Electricity Storage Project Assessment

Publication type:
Consultation
Status:
Closed (with decision)
Publication date:
Last updated:
Closed date:
Topic:
Electricity generation, Low carbon and nuclear energy
Subtopic:
Electricity storage, Long duration electricity storage
Industry sector:
Long duration electricity storage

Our proposed approach for assessing which Long-Duration Electricity Storage (LDES) projects should be awarded a cap and floor regime.

Details of outcome 

We wanted your feedback on our project assessment framework for LDES projects applying under the first application window of the cap and floor regime.  We received 44 responses from developers of LDES technologies, trade associations, investors, and individuals.    

The consultation confirmed broad stakeholder support for the proposed Multi-Criteria Assessment (MCA) Framework.  After considering all the responses, we have decided that: 

  • projects will be assessed based on economic, strategic, and financial merits without predetermined weightings 
  • our assessment will include socio-economic welfare benefits with added focus on deliverability, evidenced based revenue forecasts, and system benefits 
  • competitive bidding will be limited to two parameters 
  • modelling counterfactuals will be updated to ensure fairness and consistency across LDES technologies 

Read the full outcome 

The LDES cap and floor regime can now proceed to the project assessment stage where eligible projects will be asked to submit further information about their projects.  

Decision on the project assessment framework for Window 1 LDES cap and floor regime [PDF, 416.15KB]
LDES Project Assessment non-confidential consultation responses [ZIP, 4.51MB]

This decision should be read alongside the: 

Original consultation

Consultation description

Ofgem, working with the National Energy System Operator (NESO), is seeking views on our proposed approach for assessing which long duration energy storage (LDES) projects should be awarded a cap and floor regime. LDES assets are essential to building a smart, flexible energy system capable of integrating large volumes of low-carbon electricity, heat, and transport. By enabling the storage of electricity when supply is high or prices are low, and releasing it during periods of high demand or cost, LDES can help reduce waste, lower prices, support decarbonisation, and strengthen energy security. 

Who should respond

This consultation is particularly relevant to LDES projects applying under the first application window, which opened on 8 April 2025. We also welcome input from stakeholders, including industry participants, energy experts, and members of the public. Your feedback will help shape a fair and effective assessment process that supports the Government’s Clean Power 2030 goals. 

How to respond

To respond, please submit your views in a PDF document on headed paper, clearly identifying the responding organisation or individual. Send your response to LDES@ofgem.gov.uk with the subject line: Project Assessment Consultation Response from [company/individual name]. We encourage all interested parties to contribute their perspectives. 

The deadline for responses is 25 June 2025. We aim to publish the final Project Assessment framework in Q3 2025. 

Consultation documents

Consultation on LDES Window 1 Project Assessment [PDF, 438.59KB]
Proposed NESO Assessment Methodology for LDES Window 1 [PDF, 1.74MB]

Respond name

Mark Horley

Respond email