First of its kind ‘high-density’ hydro system begins generating electricity in Devon

The engineering team at the RheEnergise demonstration plant. The design means the principles of hydropower could be used in many more locations than traditional hydropower dams. Photograph: Taylor Keogh Communications/RheEnergise

A hillside “battery” outside Plymouth in Devon has begun generating electricity using a first of a kind hydropower system embedded underground.

The pioneering technology means one of the oldest forms of energy storage, hydropower, can be used to store and release renewable energy using even gentle slopes rather than the steep dam walls and mountains that are usually required.