Electric Mountain, Snowdonia, Wales

Ffestiniog Power Station

• Electric Mountain is the name of a visitor centre that provides tours of one (Dinorwig) of the two power stations situated in the Snowdonia Region of Wales.
• Dinorwig and Ffestiniog are the two storage plants, each of which provide energy for the GB electricity market.
• Each of Dinorwig's six generating units can produce 288MW of electricity, offering a combined station output of 1728MW. Ffestiniog's four 90MW units have a combined generating capacity of 360MW.
• Dinorwig's reversible pump/turbines are capable of reaching maximum generation in less than 16 seconds. Using off-peak electricity the six units are reversed as pumps to transport water from the lower reservoir, back to Marchlyn Mawr.
• At Ffestiniog, water is captured in Tan-y-Grisiau and pumped back to Llyn Stwlan, usually overnight, to complete the cycle.

How Pumped Storage Works:

• Two reservoirs at different altitudes are required. When the water is released, from the upper reservoir, energy is created by the downflow which is directed through high-pressure shafts, linked to turbines.
• In turn, the turbines power the generators to create electricity
• Water is pumped back to the upper reservoir by linking a pump shaft to the turbine shaft, using a motor to drive the pump.