This section contains links to all of our Electricity Capacity Reports and Security of Supply related documents.

Electricity Capacity Report 

Electricity Capacity Report (ECR) summarises the modelling analysis undertaken by National Grid ESO, in its role as the Electricity Market Reform (EMR) Delivery Body. The report supports the decision by the Government on the amount of capacity to secure t​​hrough the Cap​​acity Market Auctions for delivery in T-1 and T-4 Delivery Years.

> 2023 Electricity Capacity Report, 2023 ECR Summary and 2023 ECR Data Workbook

> 2022 Electricity Capacity Report​

> 2021 Electricity Capacity Report​

> 2020 Electricity Capacity Report​

> 2019 Electricity Capacity Report​

> 2018 Electricity Capacity Report​

> 2017 Electricity Capacity Report

> 2016 Electricity Capacity Report​

> 2015 Electricity Capacity Report

Under the CM Regulations and Rules, we are oblig​​ed following Prequalification to advise the Secretary of State if any adjustment should be made to the demand curve in light of Prequalification results (or any additional new information) and provide a recommendation as to any adjustment to be made. Our recommendations for the T-1 and T-4 Auctions are included in the “Adjustments to Demand Curve” report which is published in this section.

Link to latest report​

Technology De-rating Method Industry Consultations

‘De-rating’ factor is applied to all forms of electricity generation as we do not assume that 100% of capacity will be available 100% of the time. Generating Plant can break down from time to time and wind and solar output varies day to day. Applying a ‘de-rating factor’ helps us to determine how much electricity generation is required to meet the Government’s Reliability Standard. This section contains information related to de-rating factor reviews and projects undertaken.

> 2022 De-Rating F​actor Methodology for conventional embedded generation technologies response 

> 2022 De-Rating F​actor Methodology for conventional embedded generation technologies Industry Consultation

> 2019 De-Rating F​actor Methodology for Renewables’ Participation in the CM Consultation Response Summary​

> 2019 De-Rating Factor Methodology for Renewables’ Participation in the CM Consultation

> 2017 Storage De-Rating Factor As​sessment Report

> 2017 Storage De-Rating Factor Assessment Consultation