Analysis
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| OCTOBER 2022 | UTILITY WEEK
Pump it up
Utility Week Innovate digs into plans to deliver
up to 1.5GW and 30GWh of storage at Coire
Glas, the fi rst large-scale pumped hydro scheme
to be built in the UK for more than 30 years.
I
t's forecast that SSE Renewables' Coire
Glas pumped storage plant – located in
Scotland's Great Glen between Fort Wil-
liam and Inverness – will create enough stor-
age capacity to power three million homes
for up to 24 hours, more than doubling Brit-
ain's existing capacity.
A‚ er a revised application to increase
proposed capacity from 600MW to 1,500MW
was approved by the Scottish Government in
October 2020, ground was broken in Novem-
ber 2021. The project is expected to take
between Ž ve and six years to complete, will
cost more than £1 billion and boast an opera-
tional life of more than half a century.
During periods of low demand or sur-
plus generation, electricity will pump water
from Loch Lochy to an upper reservoir more
than 500m above, storing energy. This is
then released by using the water to generate
hydro-electricity at a time when demand is
high or other variable generation – such as
wind or solar – is low.
SSE Renewables is currently conduct-
ing assessment work at the site to deter-
mine whether construction can proceed as
planned. Kicking o• this month, an exten-
sive programme of exploratory works is
required before a Ž nal decision can be taken.
According to SSE – whose highland infra-
structure stretches back to the "hydro revo-
lution" of the forties and Ž ‚ ies and spans
54 powers stations, 78 dams and more than
300km of underground tunnels – the scheme
will be able to provide minute-by-minute
balancing services to the grid but also sus-
tain services for long periods, up to days at a
time if needed.
The role of long-term storage
While pumped hydro is a well-established
technology, Coire Glas represents the Ž rst
project on this scale to be developed in the
UK for more than three decades, according to
project director Ian Innes.
