Drax Group’s 440-MW Cruachan Power Station, a hydroelectric pumped storage plant, has begun supplying critical system support services to keep Britain’s power system secure.
As part of a six-year contract, one of the generating units at Cruachan is providing National Grid Electricity System Operator (ESO) with vital system support services, such as inertia, to keep power supplies secure without generating any electricity and enable more wind and solar power to come online. Inertia acts like a shock absorber, helping to control changes in frequency, to ensure the grid maintains a frequency of 50Hz. Without enough inertia available to reduce the rate of frequency changes that occur on the system, the grid is more vulnerable to power cuts, Drax said.
Drax is the first of five providers to supply system support services to the grid in a move expected to save consumers £128 million (US$161.8 million) over the course of the contracts. ESO has also secured contracts for system support services with Rassau Grid Services (Welsh Power), Statkraft, Triton and Uniper.
The new partnership between Drax and National Grid ESO, which is responsible for balancing supply and demand for electricity in Great Britain, is part of an approach to managing the decarbonization of the grid — securing electricity supplies, saving consumers money and helping to enable more wind and solar power.
Inertia was traditionally a by-product of the kinetic energy in the spinning parts of large traditional power stations. As the country’s electricity system has transitioned from traditional sources of power like coal to renewables, such as wind and solar, there has been an increased need to separately procure inertia to maintain stable, secure supplies of power. Through the stability tender, the ESO has procured the equivalent amount of inertia as would have been provided by around five coal-fired power stations.
To achieve its goal, Drax will use a small amount of power from the grid to spin the turbine 600 times every minute, offering inertia to the grid without generating unneeded electricity.
“This new partnership underlines our commitment to enabling a zero carbon, lower cost energy future,” said Will Gardiner, chief executive officer of Drax. “Cruachan has played a critical role in the growth of renewables over the last decade and this new contract will enable more wind and solar power to come onto the grid in the years ahead.”
Julian Leslie, ESO head of networks said, “The GB electricity system is one of the most advanced in the world, both in terms of reliability and the levels of renewable power, and we’re really excited to be adding to that with this new approach to operating the grid. Our contracts for stability services with providers such as Drax are cheaper and greener, reducing emissions and saving money for electricity consumers.
“This approach — creating a market for inertia and other stability services — is the first of its kind anywhere in the world and is a huge step forward in our ambition to be able to operate the GB electricity system carbon free by 2025.”
The Cruachan Power Station, in Argyll, is located in the hollowed-out Ben Cruachan Mountain. The project was commissioned in 1965.