The only visible signs from outside Elidir Mountain of the Dinorwig power station are the water outlet supports at 'Lynn Perris' lake level, & the entrance tunnel's. All power cables are buried below ground & emerge 6 miles from the station, The water feeds are from the underside of Marchlyn Mawr lake, & the Man made surge lank, Only visible from the air or satellite.
Elidir used to be known as Slate Mountain is now known as Electric Mountain.
The scale of this hydro-electric pump storage station is awesome, The entire power station is totally hidden from view, buried deep inside a mountain that used to be known as Dinorwig slate quarry.
There are 10 miles of 2 lane underground road tunnels, 10 miles of underground water pipes, (The main surge feed pipe is 100 feet in diameter) The Turbine, Generating & Transformer halls are underground cathedral sized caverns, each the length of two football pitches, which are absolutely mind blowing to see. This environmental friendly Hydroelectric pump storage power station can switch on to full power in seconds, with sufficient energy to power all the homes in Wales.
There are public tours available, I was pleased I had decided to take the tour, & would recommend your do the same if in the area.
This is a high security location, with typical security restrictions, the worst for a waymarker is No Cameras or Phones, & No photography.
"From the Visitor Centre, a First Hydro bus will transport visitors to the Power Station itself. Descending deep inside ancient Elidir mountain's labyrinth of dark and imposing tunnels, visitors will experience one of man's greatest engineering achievements.
First Hydro Safety Procedures require that all visitors wear Safety Helmets on the Underground Tours. These helmets are not suitable for use by babies and young children, we therefore cannot allow any children under the age of 4yrs on the tours. Anyone suffering from claustrophobia may suffer some discomfort while underground and they are advised not to take the tour. As visitors are entering an industrial site suitable footwear must be worn, specifically no flip flops, sandals, open toes or high heels.
Restrictions: No cameras, mobile phones, handbags, rucksacks etc allowed on the tour. Lockers are provided.
• From the Electric Mountain Centre a tour bus will transport visitors underground to the power station.
• From the main inlet valve gallery, you can then witness Dinorwig's massive pump/turbines in action.
• From the viewing gallery an underground film show explains the building and commissioning of the Power Station.
• The bus then takes you up to the surface and then back to Electric Mountain." text Source: (
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Dinorwig Power Station.
"When it was fully commissioned in 1984, Dinorwig Power Station was regarded as one of the world's most imaginative engineering and environmental project.
Today, Dinorwig's operational characteristics and dynamic response capability are still acknowledged the world over. Dinorwig is the largest scheme of its kind in Europe.
Dinorwig is comprised of 16km of underground tunnels, deep below Elidir mountain. Its construction required 1 million tonnes of concrete, 200,000 tonnes of cement and 4,500 tonnes of steel.
The station's six powerful generating units stand in Europe's largest man-made cavern. Adjacent to this lies the main inlet valve chamber housing the plant that regulates the flow of water through the turbines.
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." Text Source: (
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Address.
Mynydd Gwefru Electric Mountain Llanberis, Gwynedd, LL55 4UR