The synchronous condenser, built by RWE at its existing Pembroke power station site, is a large rotating machine that provides clean inertia. Inertia is a key characteristic of the electricity system that helps resist sudden changes in frequency following unexpected disturbances. The stability technologies will help cut emissions, strengthen energy security, and save consumers up to £9bn in system costs over the years ahead. Director of Engineering at NESO, Matt Magill, said: “Projects like Pembroke will help reduce emissions, strengthen energy security, and save consumers up to £9bn as Britain moves towards a clean power system. The next phase will add a further 26.9 GVAs, more than doubling the amount of clean stability available on the system.