Britain’s first big pumped hydroelectric power station is to undergo a £50 million refurbishment to extend its life by 20 years. The Ffestiniog plant in Snowdonia was built in 1963 and can generate 360 megawatts of electricity, enough to supply north Wales, for up to three and a half hours at a time. It works by releasing water from an upper reservoir down through tunnels in the mountain to turn turbines and generate electricity, before discharging it into a lower reservoir. Water is pumped back up when electricity supplies are plentiful, typically at night. Engie, the facility’s French owner, said that it had awarded a £50 million contract to refurbish two of the four units at the ageing power station, which otherwise would have had to close by around 2020. Updates to the other two units, which can keep running until 2025 without a big refit, could follow. Engie said that the plant was profitable and was expected to play an increasing role as Britain builds more wind and solar plants and needs flexible power to manage intermittent supplies. It is usually called upon by National Grid to generate for between five and twenty minutes at a time to balance short-term drops in supply such as a lull in wind power or clouds passing over a major solar array.
Times 16th Aug 2017 read more »