UK September coal-fired power output rises on the year
London, 5 October (Argus) — The UK's coal-fired power output turned out slightly higher year on year in September owing to lower gas-fired capacity availability, but strong winds have limited the grid's call on coal during the first few days of October.
The UK's coal-fired fleet generated an average of 1,416MW last month, up from only 640MW in August and 1,379MW in September last year.
The majority of the supply was produced at UK firm Drax's Selby-based plant, but the grid also called on capacity at the Ratcliffe, Fiddlers Ferry, West Burton A, Cottam, Aberthaw and Eggborough facilities over the course of the month.
The grid was forced to increase its call on coal-fired units to cover a shortfall in supply from gas-fired plants, availability of capacity at which was limited because a large number of generators chose to carry out maintenance at their facilities before the start of the capacity market regime, which came into force on 1 October.
Combined-cycle gas turbine units produced an average of roughly 12.4GW, which despite being the highest for any month since May, compared with a 13.8GW average in September last year.
But the year-on-year increase in coal-fired power output was still surprising given weaker September power system demand on the year, and stronger wind power supplies.
The transmission network was required to meet an average of 28.9GW of demand, compared with 29.2GW in September 2016, as lower temperatures appeared to result in weaker demand for cooling. The average temperature in London turned out at around 15.1°C, compared with 18°C in September last year, when a heat wave had seen levels rise to highs of close to 33°C on some days.
The continued deployment of embedded generation capacity — which feeds its output directly into localised distribution networks — has also slightly reduced the share of demand that the wider transmission network has to meet since last year.
Average wind power output in September was the highest for any month since March, at 3.4GW, which was 1GW higher on the year.
And wind levels have turned out extremely high in the first days of October. Metered supply averaged 7.2GW on 1-4 October, with output rising to a new record high of 8,817MW on 1 October.
This has resulted in coal-fired power output dipping to an average of only 520MW in recent days, with production turning out at 0MW over an entire 24-hour period for only the second time since the industrial revolution over the weekend.
Wind levels are forecast to remain relatively high until at least mid-October, which could continue to limit the requirement for coal-fired power generation. But weather forecasts point towards a cooler spell of weather in the second half of the month, when overnight temperatures in London are expected to dip below long-term seasonal norms.
Coal-fired power generation averaged roughly 2.5GW in October last year, before rising to 4.3GW in November.
Average UK power system supply MW