At a glance

Prices

An uptick of 43% in average clearing price from May to June, with more instances of high (>£5/MW/h) clearing prices than the previous month.

Day-to-day price volatility remains from May, with price swings driven by National Grid Electricity System Operator’s (NG ESO) strict aversion to overholding Short Term Operating Reserve (STOR) capacity.

Volumes

Procured volumes remain constant at 1312 MW (avg.), in line with NG ESO's procurement targets – note this excludes 400 MW of firm long-term STOR contracts enduring to 2025.

Gas reciprocating engines were the dominant technology in day-ahead Short Term Operating Reserve (DA STOR) during July, accounting for 39% of firm STOR capacity. Pumped storage saw an increased share of awarded contracts, up 5% from May.

Service cost

Total service cost to NG ESO for DA STOR availability was £1.4m. This increased in line with the average clearing price, with contracted volume remaining constant.

Market share

Centrica secured the highest revenues from DA STOR, taking 18% of the total revenue with their 245 MW site in Peterborough, which secured contracts every day in June.

Individual site revenues across June ranged from £1075/MW to £42/MW, driven largely by the number of contracted days.