UK day-ahead power contracts retreated on Tuesday, halting a three-day winning streak, as a bearish NBP gas market and falling demand offset the bullish impact of plummeting wind generation.
Baseload power for Wednesday delivery fell to GBP54.95/MWh, erasing GBP1.30 in value on the day before the 11:00 am London market close Tuesday.
Similar movements were seen on the N2EX and APX exchanges auction where the spot base UK contract cleared at GBP54.77/MWh on Tuesday, compared with Monday's settlement price of GBP55.31/MWh, according to the exchanges data.
Healthy gas supplies coupled with easing weather concerns weighed on the NBP prompt gas market, which in turn gave a bearish price signal to the power market.
On the NBP gas hub, the within-day and day-ahead contracts declined to 58.25 pence/therm and 58.70 p/th respectively, down from the previous day-ahead assessment of 60.10 p/th.
UK system operator National Grid said it estimates wind power output on Wednesday to drop by nearly half on the day to 3.7 GW, down from Tuesday's peak forecast of 6.1 GW.
At the same time, electricity demand on Wednesday is expected to increase marginally to 50.2 GW, up from 49.9 GW on Tuesday, after Monday's peak demand fell short of initial estimates of 49.1 GW to reach 48.7 GW, the grid data showed.
However, increased nuclear availability, following the restart of one of the UK's nuclear reactor units, along with steady available gas and coal generating capacities eased supply pressures.
EDF Energy's 620 MW Hartlepool nuclear unit 2 was returned to service on Tuesday after a planned maintenance outage, the operator's website showed. This helped increased available nuclear capacity to above 8 GW on Wednesday.
Also, coal and gas availabilities stood at 12.1 GW and 27.1 GW respectively, Grid data showed.
At midday Tuesday, energy generated from fossil fuel plants -- coal and gas -- reached 10.3 GW and 20.1 GW, as wind output plunged to below 1 GW, down from more than 4 GW seen at around the same time on Monday, Grid said.
Nuclear power supplies rose to 8.1 GW, while only the Netherlands was seen exporting power to the UK, sending 164 MW at midday.
