The Rheidol Hydro Electric Scheme is the largest of its kind in England and Wales. Since 1962 the scheme has generated renewable energy by using the rainwater that falls on the surrounding mountains.

Located within and above the scenic valley of the river Rheidol near Aberystwyth in Mid-Wales, the hydropower plant is made up of an interconnected group of reservoirs, dams, pipelines, aqueducts and power stations, and covers a total area of 162 square kilometres. The annual energy production is about 85GWh – enough to power approximately 12,350 homes.