More than just Dinorwig Power Station's public interface, Electric Mountain has interactive exhibits on hydropower that explain why the power station is worthwhile, even though it consumes more electricity than it produces. It's also the starting point for a fascinating guided tour through rock tunnels into the power station's guts, 750m under Elidir mountain.
The center is by the lakeside on the A4086.
The Dinorwig pumped-storage power station is the largest scheme of its kind in Europe. Spanning 16km of tunnels deep within the mountain, it required one million tonnes of concrete, 200,000 tonnes of cement and 4500 tonnes of steel to construct, and it incorporates the largest human-made cavern in Europe, big enough to house St Paul's Cathedral. The station uses surplus energy to pump water from Llyn Peris up to Marchlyn Reservoir; when half the population switches on their kettles for tea during a TV ad break, the water is released to fall through underground turbines. Dinorwig's reversible turbine pumps are capable of reaching maximum generation in less than 16 seconds, supplying electricity pretty much instantly to meet demand.
