The below article originally referenced a REMIT post related to the Cruachan pumped-storage hydropower plant. The post, which appeared on an amalgamated REMIT information site, differed from that made available by the plant's operator at the time. The outage at the Cruachan plant did not contribute to National Grid's system warning.
UK power system operator National Grid was accepting four-figure offers to generate electricity from individual power plants at 16:30 London time on Wednesday to ensure adequate supply margins in the midst of a rare system warning.
Data showed offers from the Severn Power gas-fired plant to generate electricity for £2,500 (€3,540)/MWh had been accepted as the warning, which covered the peak period 16:30-18:30, entered its first hour.
The grid operator was forced to shift up through the gears it has at its disposal as it scrambled to deal with a number of unplanned outages, including the loss of some major coal-fired capacity, as well as some pumped-storage facilities that would usually be called upon to fill unexpected generation gaps.
At the time of writing late on Wednesday afternoon National Grid had:
Issued a notification of inadequate system margin to cover the period 16:30-18:30 – in short a call that maximum generation may be instructed from available production units to ensure a safe supply surplus
Accepted short-term offers from individual power plants as high as £2,500/MWh to generate power
Dispatched its demand-side balancing reserve (DSBR) to cover the 17:00-17:30 – one of two “last resort” measures the grid operator has at its disposal alongside the short-term balancing reserve. A DSBR issuance means energy intensive users such as factories would be paid to use less electricity
Entered into a rare cross-border balancing transaction to snap up 200MW of capacity from Irish counterpart Eirgrid at €390/MWh
Remit data showed a series of unexpected outages at coal- and gas-fired power plants in the 48 hours leading up to the initial inadequate margin warning, which was issued at 13:30.
At the time of writing balancing market prices had peaked intraday at £420.00/MWh.
However UK power traders downplayed the magnitude of the incidents, despite the extremely high intra-day spikes, with a number of plants expected to return to the grid on Thursday. One trader labelled the gains “an overreaction with the market quick to panic”. Prompt prices would correct downwards soon, he added.
A second source had sympathy with National Grid’s predicament, agreeing it had been forced to act as the power plant losses came one on top of the other. “Supply margins are looking stronger from here on,” he said.
Hourly day-ahead prices, while still high for peak delivery times, also indicated an easing of nerves. Power to be delivered between 17:00-18:00 on Wednesday had settled at £235.81/MWh on the N2EX exchange the previous day. The corresponding hourly product for Thursday was priced at £131.81/MWh. firstname.lastname@example.org