Water – Snowdonia has a lot of it! The combination of mountains and lakes makes it ideal for generating power via hydroelectric schemes, where water and gravity combine to turn massive turbines.
The biggest of all is within ambling distance of our hotel, and there are others too. There are more in the pipeline – ahem! – with a £100m scheme earmarked for the other side of Llanberis.
So if the wet stuff is falling from the sky, why not head underground and learn how it helps put your kettle on?
Dinorwig Power Station – Electric Mountain
Dinorwig, the power station the public can visit via the excellent Electric Mountain attraction, is a man-made marvel. Even though it’s more than two decades old (the turbines started turning in 1984) it’s still the largest hydroelectric scheme of its kind in Europe, in the continent’s largest man-made caverns.
The visitor tour takes you by minibus along 10 miles of underground tunnels, deep under Elidir Fawr mountain. You can get up close to the six massive generating units and the plant that regulates the flow of water through the turbines. All this inside a massive cavern measuring 51 metres (167 ft) high, 180 metres (590 ft) long, and 23 metres (75 ft) wide, known as “the concert hall.”
When power is needed, the station can fire up to maximum capacity (1,728 megawatts) in 16 seconds – so there’s no need to worry about not getting that cup of tea. When it’s not generating electricity, the turbines can pump in reverse, sending water back up the pipe to the Marchlyn Reservoir, 630m above sea level.
Building Dinorwig was a significant feat of engineering, let alone the excavation (12 million tonnes was dug out of the mountain). The station needed one million tonnes of concrete, 200,000 tonnes of cement and 4,500 tonnes of steel to construct.
Electric Mountain is Dinorwig’s Visitor Centre in Llanberis, just a few hundred yards from the hotel. Inside you’ll find a gift shop and café and the starting point for the power station tour. Admission to the visitor centre is free but charges apply for the hour-long tour of Dinorwig.
Ffestiniog Power Station – the UK’s first of its kind
While Ffestiniog Power Station lacks a visitor centre, you can walk close to it or view it from the Ffestiniog Railway which passes close by. Just outside the village of Tanygrisiau, Ffestiniog Power Station and its feeder lake (Llyn Stwlan) can be explored while walking Moelwyn Mawr mountain.
Ffestiniog was the first pumped storage power facility in the UK – the same method of power generation as used at Dinorwig. Although older than Dinorwig (it was commissioned in 1963), Ffestiniog’s four generating turbines can still achieve a combined output of 360M megawatts of electricity – enough to supply the power needs of North Wales for several hours.
A total of 27 cubic metres of water per second is sent through the station and captured in Tan-y-Grisiau reservoir, then overnight it is pumped back up to Llyn Stwlan to complete the cycle.
You can read more about Ffestiniog Power Station here.
Maentwrog Power Station – 90 years old in 2018
Maentwrog is one of Snowdonia’s early hydroelectric power stations, opened in 1928. While it’s often thought of as the oldest, that title actually belongs to Cwm Dyli Power Station in Nantgwynant, which began operating in 1906. Cwm Dyli was pioneering for its time – not only is it nearly 30 years older than Maentwrog, it was also the first in the UK (and possibly the world) to be connected to a national grid.
Unlike Dinorwig and Ffestiniog, Maentwrog does not use pumped water storage. Instead, water simply rushes down a pipe from a high lake into the river and sea below – leaving Mother Nature to take care of the recycling!
Located in the village of Maentwrog on the banks of the Dwyryd Estuary, the station is able to generate 30 megawatts of electricity. When it opened, its maximum output of 18 megawatts – generated by three turbines – was enough to power North Wales. A fourth turbine, added in 1934, increased its capacity so that today it can power around 12,000 local homes.
Maentwrog draws its water from Trawsfynydd Lake, which is itself fed by man-made channels (you can spot these from the minor roads south of Trawsfynydd village when heading towards Dolgellau on the A470). From there, water travels down a mile-and-a-half pipeline to drive two turbines, which you can glimpse from the Harlech road (A496) beside the power station.
As an aside, profits from Maentwrog still go towards nuclear decommissioning projects, including the nearby Trawsfynydd nuclear site.
More hydro-power coming to Llanberis?
Glyn Rhonwy is the former slate quarry you pass driving from Caernarfon into Llanberis. There have been many ideas to transform the area and the latest, a new hydro-electric scheme, could start to become a reality in 2018.
The station would be of the pumped-storage variety, like Ffestiniog and Dinorwig, drawing water from a high lake and discharging into Llyn Padarn before pumping water back up at night. If it goes ahead, the £100m scheme will be capable of generating 700 megawatts of electricity, enough to supply seven hours of power to 200,000 homes every day.