The £100 million Glyn Rhonwy pumped storage hydropower project in North Wales has been granted a Development Consent Order (DCO) by UK Business, Energy and Industrial Strategy Minister, Greg Clark MP.

Lying just outside the Snowdonia National Park, but in designated sites for ecology, landscape and cultural heritage, the scheme is the UK’s first onshore hydro scheme to go through the Planning Act 2008 and the first such scheme in a generation.

Using two disused quarries near Llanberis, one high, one low, Snowdonia Pumped Hydro’s 99-megawatt project will generate electricity, as well as store energy that can be used to help balance the national grid at times of peak energy use. Water will be transferred via a large-diameter tunnel between the two reservoirs using reversible pump turbines, both to generate electricity when required at peak times and to use electricity to fill the upper reservoir when power demand is low. An underground power plant will be located in a deep shaft next to the lower reservoir.

Due to its previous slate mining history, the site also has over 400 archaeological features, as well as multiple protected species, so an array of mitigation measures have been embedded into the project as part of the Environmental Impact Assessment (EIA).

The project was previously approved as a 49-megawatt scheme by Gwynedd Council, but the Energy Market Reform changed the financial viability of the project and it was updated for a DCO application. The physical nature of the updated scheme has not increased from the original design, but it now includes more powerful turbines.

The successful DCO application is the result of six years’ work by global infrastructure services firm AECOM with Snowdonia Pumped Hydro, a subsidiary of Quarry Battery Company. The planning application was led by commercial property agency GVA, with legal support provided by Burges Salmon.

Catherine Anderson, EIA associate director at AECOM, said: “Today’s DCO marks a significant milestone for this important project that will help boost the UK’s ability to respond to changing patterns of electricity generation and demand.”

Construction is expected to start within the next 12 months.

Photo: Snowdonia Pumped Hydro