Glyn Rhonwy

The Glyn Rhonwy site in Llanberis (North Wales, UK) comprises two disused slate quarries which will be re-purposed as reservoirs for a new-build pumped hydro scheme.

A tunnel connecting them will allow water to flow from the upper reservoir to the lower through a hydro turbine to generate power when demand is high.

In reverse, the turbine will pump water back to the upper reservoir, recharging the energy store for later use using energy when demand on the grid is low. 

Using off peak power to displace peak generators will deliver carbon savings of 50,000 tonnes of carbon dioxide each year, equivalent to 20,000 cars being taken off the road.

Key Figures

Working volume : 1.3 million tonnes of water

Power: 100MW, enough to power 100,000 homes for 7 hours per charge.

Carbon Payback time: 6 months.

Project life: 125 years.

Current Status

The Glyn Rhonwy project was granted a Development Consent Order by the Department for Business, Energy & Industrial Strategy in March 2017.

We are currently working on fulfilling the various tasks required to start construction of the project.

We are looking for development partners to help deliver the project going forward.

Go to The Glyn Rhonwy project website for more information.