Yesterday’s decision to approve plans for a 600MWh electricity pumped storage facility in disused slate quarries near Llanberis in north Wales has been hailed by the scheme’s developer as a key step in enabling Britain’s low carbon energy strategy.

Quarry Battery Company, which is aiming for the £100m site to be operational by 2017, said the decision by Gwynedd council’s planning committee heralds a new generation of pumped storage facilities that can provide a solution to the intermittent nature of power from wind and other renewables. Many could be built on brownfield sites like the Glyn Rhonwy slate quarries, minimising visual and environmental impact.

Pumped storage operates like a giant battery. Low cost surplus and off-peak electricity is used to pump water from a lower to an upper reservoir. During times of peak demand water flows back downhill through a turbine to generate electricity. Pumped storage sites can also absorb power from wind turbines and other renewables, releasing it back into the grid at peak times to displace high carbon oil and gas generation.

Previously, the concept was thought to be viable only when used on a large scale, such as the 1800MW facility at Dinorwig (Electric Mountain) in north Wales, commissioned some 30 years ago and the last major commercial scheme to be built in England and Wales.

QBC, now the UK’s centre of expertise in deploying the technology, is proposing a new generation of pumped storage facilities built on a much smaller-scale, arguing that they are economically viable and environmentally more acceptable than another single Dinorwig-sized facility.

“Pumped storage is the missing piece of the jigsaw for renewables and can help Britain keep the lights on,” said QBC managing director Dave Holmes. “Our scheme for the Glyn Rhonwy quarries is just the start. By putting small-scale storage near to centres of energy generation such as wind farms, and others near centres of heavy consumption such as major cities, we will cut down on distribution losses and network transmission costs, making whole regions of the UK increasingly self-sufficient in renewable electricity.”

A growing number of energy experts and environmental groups including Friends of The Earth agree that the UK needs more pumped storage, believing that it will enable the UK to resolve a central problem with renewables – that they are weather- and time-dependent, and therefore intermittent generators. Not only will pumped storage smooth out the supply of electricity, but it will enable conventional power stations to be stood down, rather than kept on standby to fill gaps in generation. This will save further costs and carbon emissions.

The Glyn Rhonwy scheme looks set to provide a substantial boost to the regional economy during the construction phase, while up to 30 full time jobs will be created to operate the site. I

The Quarry Battery Company (www.quarrybattery.com) was founded from ideas that originated during studies at the Centre For Alternative Technology near Machynlleth. QBC’s scheme for Glyn Rhonwy near Llanberis was designed in consultation with AECOM, Gwynedd Council, Cadw, Countryside Council For Wales and Environment Agency Wales.

QBC is now looking for partners to build and operate the facility.