Muted demand for air conditioning and a strong supply contribution from distribution network-connected wind farms pulled power demand from the UK transmission network down
Power system demand averaged only 26.2GW during all hours of the week beginning 31 July, which was down from 26.9GW during the previous week, and below the previous record low of 26.5GW from mid-August of last year.
Unseasonably low temperatures weighed considerably on cooling demand levels last week.
The average temperature in London turned out at only around 17.7°C, which compares with an average of 19.4°C during July and a long-term seasonal norm of around 18.5°C for the first week of August. And temperatures in the capital slipped to lows of around 10.6°C over the weekend of 5-6 August, which was the lowest they have been since mid-June.
The low temperatures coincided with strong wind power generation, with metered supply rising to an average of around 3.4GW, which was the highest it has been since early June.
And with embedded wind power capacity — which feeds its production directly into the local distribution networks — also supplying more, the share of demand that the wider transmission network had to meet was further cut.
The weak demand reduced the grid's call on thermal plants to operate last week and the UK's combined-cycle gas turbine plant fleet was only required to generate an average of around 9.5GW, compared with 12GW during July. This was the lowest amount gas-fired plants had produced over one week since early
And coal-fired units produced an average of just 390MW last week, which was only marginally above the 305MW all-time low. Only capacity at German utility Uniper's Ratcliffe-on-Soar and UK utility Drax's Selby based coal-fired facilities was required to operate over the course of the week.
UK power market prices reacted to the weak demand, with the N2Ex day-ahead base-load auction settling at an average of ?39.67/MWh, compared with an average ?40.82/MWh settlement during July.