Drax

Drax commissions 3 new 299MW Open Cycle Gas Turbine (OCGT) power plants that incorporate SSS Clutches as part of their FlexGen portfolio to support UK energy security.

Drax is a renewable energy company engaged in generating renewable power, producing sustainable biomass, and selling renewable electricity to businesses. They are the UK’s largest single source of renewable electricity.

Drax Group has invested in 3 Open Cycle Gas Turbine (OCGT) projects as part of it’s FlexGen portfolio through it’s subsidiaries Hirwaun Power, Progress Power and Millbrook Power. Each power plant is run locally as a peaking power plant operating up to 1500 hours per year to support the UK grid at times of peak electricity demand and when intermittent renewable technologies are unable to produce the power required to keep the country running.

“It’s great to see the successful commissioning of our first open cycle gas turbine (OCGT) plant, Hirwaun Power Station in South Wales. This is a big milestone for Drax - welcoming Hirwaun into our FlexGen portfolio and marking our first power station in Wales. Hirwaun is the first of three 299MW OCGTs we’re developing in England and Wales. Together, these sites will provide around 900MW of flexible generation to support UK energy security and enable more renewable power on the system. Thanks to our teams, partners, and suppliers for bringing Hirwaun into operation.” Lee Dawes, Chief Operations Officer, Drax Group plc

Each OCGT has a gross rated output of 299 MW and is supplied with a Siemens SGT5-4000F gas turbine and a size 360T Encased SSS Clutch. These new peaking plants will only generate power for short periods each year. When not generating power, the generator can be left spinning as a synchronous condenser, providing reactive power for voltage control, high fault current and inertia to slow down the rate of change of frequency (RoCoF), all critical factors to consider as more inverter-based renewable energy sources are added to the grid. This hybrid operation is possible because the SSS Clutch can quickly and reliably decouple the gas turbine from the generator.

To attempt to achieve the same reactive/inertia support with power electronics would be considerably more expensive and neither power electronics or a stand-alone synchronous condenser without a prime mover can provide active power when needed by the grid.

As the UK transitions to nett zero with a Government target to decarbonise the power system by 2030, the electrical grid transmission system needs increasing support. With much of the load in the South and generation switching from large fossil fuel plants in the centre of the country, to offshore wind primarily in the North. Great change is taking place at a remarkable rate.

These power stations with their small footprint and relatively fast installation time, will help support grid strength and the rapid transition to renewable energy sources in the UK while at the same time providing security of supply as they are capable of both short term and long term generation all in the one package. They support the Government and National Energy Systems Operator (NESO) objectives and provide multiple potential revenue sources so are truly revenue stacking for the owner.