A total of around 4.3 gigawatts (GW) of capacity was procured, National Grid's EMR (electricity market reform) delivery body website said in a provisional auction document.
Britain launched its power capacity market in 2014, offering to pay providers for making supplies available at short notice.
The clearing price is reached when the total offered capacity is equal to that demanded.
Auctions are usually held about four years in advance of the delivery date, with another auction for a smaller amount of capacity held a year before delivery.
Out of the total procured, the majority was for gas-fired power plants. Existing generation capacity was awarded 90.49% of the total agreements, the document showed.
Utilities such as SSE (SSE.L), opens new tab, EDF, Uniper and RWE (RWEG.DE), opens new tab, won agreements.
