Day-ahead prices in the UK were volatile during Week 38. At the beginning of the week, Baseload contracts changed hands below £31.00/MWh, but despite National Grid data showing healthy levels of back-up plant availability there was some tightness apparent in the market with System Buy Prices (SBP) spiking up to £125/MWh on Tuesday. Prices on the balancing market stayed above £119/MWh for a two-hour period during the afternoon and players said this was a major contributing factor to Day-ahead bullishness. Rising NBP gas prices also lent support to the Day-ahead Baseload and Peaks contracts intra-session on Tuesday. As a result, Day-ahead Baseload climbed to £39.00/MWh on Tuesday, with Peaks jumping to £45.00/MWh. By Wednesday, SBP prices had returned to lower levels and falling NBP prompt prices helped Day-ahead prices return to levels near £33.00/MWh. The threat of having to go into the balancing market for generators short of contracted supply was still evident with prices opening at £40.00/MWh for Day-ahead Baseload on the Wednesday morning.

Prompt contracts have the potential to be volatile during Week 39 as temperatures are set to drop in the UK at the beginning of the week, leading to increased demand. Current forecasts from National Grid show Monday and Thursday to be the tightest days of the week, with peak periods back-up plant availability of 6.5 GW and 6.7 GW respectively.