Dinorwig power station
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Dinorwig from Llanberis |
Dinorwig power station is a 1728
MW pumped storage hydroelectric scheme, near
Dinorwig, in the Pass of
Llanberis on the edge of the
Snowdonia national park in north
Wales. It is comprised of 16
km of tunnels, 1 million
tons of
concrete, 200,000 tons of
cement and 4,500 tons of
steel, housed beneath the mountain
Elidir Fawr.
The scheme was constructed in the abandoned Dinorwig
slate quarry. Water is stored at a high altitude in
Marchlyn Mawr reservoir and is discharged into
Llyn Peris through the turbines during times of peak electricity demand. It is pumped back from Llyn Peris to Marchlyn Mawr during off-peak times.
The power station is comprised of six 288MW GEC generator/motors coupled to francis type reversible turbines. The generators are vertical shaft, salient pole, air cooled units each having 12 electromagnetic poles weighing 10 tonnes a piece, producing a terminal voltage of 18kV, synchronous speed is 500rpm. From standstill, a single 450 tonne generator can synchronise and achieve full load in approximately 75 seconds. With all six units synchronised and spinning-in-air 0MW to 1800MW load can be achieved in approximately 16 seconds.
Excess water overflows to
Llyn Padarn and is lost from the Reservoir system. Both Llyn Peris and Llyn Padarn were ancestral homes to the
Arctic char, a rare fish in the
UK. When the scheme was commissioned, a fish rescue was undertaken to transfer the char from Llyn Peris to other local suitable lakes and it is believed that due to the very variable water levels in Llyn Peris, Arctic char are now absent from the lake.
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First Hydro Company
