Alderney 5 Energy Project

This underground seasonal thermal storage system connects five municipal buildings on the Dartmouth waterfront. It is the first large-scale application of geothermal seasonal cold-energy storage anywhere in the world. The system collects cold energy from seawater during winter months to chill an underground rock mass and then uses the stored thermal energy to meet air conditioning needs in warmer months by using 100 per cent renewable energy.

Cold water is drawn from a nearby harbour and is used to cool the Alderney 5 internal closed-loop fresh water system. This water is then sent directly to the recipient buildings cooling systems or, during the winter months, the water is passed through a series of boreholes. The boreholes store “cold energy” for the summer months.