The SSE-owned plant was forced to repeat its mandatory monthly test to prove to National Grid that it can be relied upon to ramp up generation should winter demand exceed the UK’s diminished supply margins, after failing to complete the test last week.
But shortly before 15.00 GMT today the company said it successfully completed its latest test, after repairing one of the plant’s three generating units and correcting a small fault on another.
The company said in a statement that Peterhead generated just 160MW of the required 780MW in last week’s test because only one of the units was able to generate power. Repair work taking place at one of the other units, and “a minor electrical” fault reduced capacity at the second.
“Both issues were rectified earlier this week,” a statement from SSE said.
The monthly tests are required of all three plants which have been contracted by National Grid under the Supplemental Balancing Reserve (SBR) to provide back-up generation this winter in case the market in unable to bring forward enough power to meet demand.
The decision to include Peterhead in the SBR has drawn criticism from power market participants who believe the plant is too old to provide reliable power generation when National Grid most needs power volume to balance out demand.
The other plants on the SBR reserve bench include Scottish Power’s Ryehouse gas-fired power plant, which passed this month’s test on 19 November, and RWE’s Littlebrook plant which has yet to be called upon to test this month.
Peterhead will complete today’s proving test at 14.55 GMT, earlier than the test which it failed last week which was due to end at 19.50 GMT, because the test “started earlier”, a National Grid spokesman said.
Under the terms of the contract the 32 year old plant is paid £250/MWh of electricity produced – whether it is called on to balance the grid, or for a proving test.