Capacity Market De-Rating Factors

De-Rating Factors used to calculate the De-Rated Capacity of each CMU and Component in each Capacity Market Auction.

NOTE: As part of our ongoing efforts to align with data management best practices and improve consistency across datasets, the column ids for this datafile will be updated on 9th September 2026 as follows:

De-Rating Factor → De Rating Factor

CKAN Data API

Access resource data via a web API with powerful query support.
Further information in the main CKAN Data API and DataStore documentation.

The Data API can be accessed via the following actions of the CKAN action API.

Query
`https://api.neso.energy/api/3/action/datastore_search`
Query (via SQL)
`https://api.neso.energy/api/3/action/datastore_search_sql`

Query example (first 5 results)
`https://api.neso.energy/api/3/action/datastore_search?resource_id=d94ff98d-39ba-40d6-9672-7433de0631ac&limit=5`
Query example (via SQL statement)
`https://api.neso.energy/api/3/action/datastore_search_sql?sql=SELECT * from "d94ff98d-39ba-40d6-9672-7433de0631ac" LIMIT 5`

A simple ajax (JSONP) request to the data API using jQuery.

var data = {
  resource_id: 'd94ff98d-39ba-40d6-9672-7433de0631ac', // the resource id
  limit: 5 // get 5 results
};
$.ajax({
  url: 'https://api.neso.energy/api/3/action/datastore_search',
  data: data,
  dataType: 'jsonp',
  success: function(data) {
    alert('Total results found: ' + data.result.total)
  }
});

A simple ajax (JSONP) request to the data API using jQuery.

import urllib2
  url = 'https://api.neso.energy/api/3/action/datastore_search?resource_id=d94ff98d-39ba-40d6-9672-7433de0631ac&limit=5'
  fileobj = urllib2.urlopen(url)
  print fileobj.read()

Download (CSV)

Data Explorer

Table Information

Auction Name

Title	Auction Name
Type	string
Description	Name of Capacity Market Auction
Comment
Example	Capacity Market Register 2027-28 (T-4)
Unit

Primary Fuel Type

Title	Primary Fuel Type
Type	string
Description	Primary fuel of CMU
Comment
Example	Gas
Unit

Generating Technology Class

Title	Generating Technology Class
Type	string
Description	Generating Technology Class of Component used to determine De-Rating Factor
Comment
Example	Combined Cycle Gas Turbine (CCGT)
Unit

De Rating Factor

Title	De Rating Factor
Type	number
Description
Comment	Factor applied to connection capacity to calculate de-rated capacity
Example	0.915
Unit

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Capacity Market De-Rating Factors

CKAN Data API

Data Explorer

Data Explorer

Table Information

Auction Name

Primary Fuel Type

Generating Technology Class

De Rating Factor