National Grid ESO has floated five contracts this year to different companies to deploy such systems which provide inertia to the transmission system. In lieu of that Welsh Power in collaboration with Siemens and Quinbrook Infrastructure will be installing a Synchronous Condenser at Rassau, Ebbw Vale. The project will be completed in 2021. Statkraft UK is also a bagger of one of these contracts and is partnering with GE Power to install a Synchronous Condenser at Keith to provide stability services to the mai grid. Link to the news: https://theenergyst.com/inertia-booster-welsh-power-and-quinbrook-start-work-on-flywheel-flex-project/