UK's 'last resort' coal units called and then canceled as imports flood in

UK power system operator National Grid Dec. 12 instructed two 570-MW coal units at Drax to prepare to generate amid freezing, calm conditions, only to cancel the order as power imports ramped up.

The Drax coal units had been contracted earlier in the year as a last resort to ensure the security of supply. Two 400-MW coal units at West Burton A were also contracted but were not called this time.

"We've issued a notification to warm two winter contingency coal units. This measure should give the public confidence in Monday's energy supply," National Grid said early Dec. 12.

By mid-day, however, the system operator had canceled the two Drax instructions as imports picked up from Norway, France, the Netherlands, and Belgium.

System data showed a peak demand forecast of 45.90 GW in the early evening of Dec. 12 as freezing temperatures barely lifted all day.

The forecast was 600 MW more than National Grid's Winter Outlook forecast weather-corrected peak demand figure of 45.30 GW.

Wind generation of just over 1.5 GW was meeting 3% of UK system demand in the afternoon of Dec. 12, with gas-fired combined cycle plants (24.05 GW, 54%) dominant in the mix, followed by nuclear (5.75 GW, 13%), biomass (2.49 GW, 6%) and, crucially, power imports (up from 6% in the morning to 11% by mid-afternoon).

"GB [Great Britain] is pricing above Continental Europe to get imports. It's a tug of war. France had some reactors return over the weekend so French day-ahead prices for today came off 50% in the auctions yesterday compared to OTC on Friday," a UK power trader said.

UK wind generation was forecast to rise modestly Dec. 12 and into Dec. 13, easing generation tightness.

System forecast data showed grid-connected and embedded wind output lifting to 3.7 GW in the evening peak period Dec. 13.

As such, peak block 5 prices for delivery Dec. 13 were assessed by Platts at GBP560/MWh ($686/MWh), down 48% day on day.

Day-ahead hourly power prices on the EPEX Spot exchange peaked at GBP2,585.80/MWh for 5 pm-6 pm delivery Dec. 12, averaging GBP674.78/MWh for the day.

Platts assessed the UK day-ahead peak block five contracts at GBP412/MWh Dec. 12, down GBP660/MWh from Dec. 9.