A lake created in the grounds provides a further source of electricity generation. A building constructed out of local stone sits at the bottom of an adjacent field, and houses two water turbine systems. The larger, which uses the 20m gross head between the turbine house and the lake, powers a 2.2kW synchronous generator. The smaller turbine is powered by the water flowing in a stream outside the building, and generates up to 850W after rainfall in the summer, and more constantly during the winter.
To prevent wildlife or debris from the stream falling into the turbine, the water passes over a Coanda effect water filter. The water passes over a vertical bank of horizontal steel wires, and any solid matter falls by gravity over the wires and back into the stream. The lake is topped up by rainfall and by a natural spring 50m below ground. The power to pump the water to the surface is supplied by three interlinked 1kW photovoltaic arrays. The water is pumped from below ground when the sun shines, with approximately 4000 gallons being delivered via a fountain jet each day during the summer, and 2000 gallons in the winter