Hydro power is produced by the 1929 Gilkes 27hp turbine which is belt-coupled to a 40kW alternator. The current gearing runs the turbine at about 190rpm, well below the optimum 400rpm, which limits the maximum power to about 11kW. Hydro systems produce a constant amount of power for a given rotational speed (necessary to produce 50Hz AC), water flow and head. To ensure that the alternator has a constant load a GP Electronics Electronic Load Controller passes any unwanted power into a ballast load. At Burton Mill the ballast load is an electric boiler in the central heating system with a reserve ballast load for emergencies. With sufficient winter rainfall we can generate enough energy to heat and power the mill
