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

Project employs technology that can be used to store and release renewable energy using even gentle slopes

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.