Hydro power is produced by the 1929 Gilkes 27hp turbine which is belt-coupled to a 20kW alternator. The current gearing runs the turbine at about 180rpm, well below the optimum 400rpm, which limits the maximum power to about 12kW. Hydro systems produce a constant amount of power for a given rotational speed (necessary to produce 50Hz AC) and water flow. The setting of the vanes surrounding the runner determine the water flow. 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.
Power data from the FITs meter: