<p>The Department does not hold data on the breakdown of constraint payments for each type of technology. Constraint payments are made by National Grid through competitive market arrangements in order to help ensure the secure operation of the electricity system. National Grid has advised that details of most individual constraint payments to generators are published at www.elexon.co.uk and www.bmreports.com, and some aggregated data, including an explanation of constraint payments made to wind generation, is published in its Monthly Balancing Services Summary, available at:</p><p>www.nationalgrid.com/uk/Electricity/Balancing/Summary</p>