Water flowing in from the Rivers Sett and Goyt is held by the blades of the turbine. Gravity pulls the water down, rotating the turbine and the attached generator to produce clean, green electricity.
With a 3m head and a 3m/s flow, the force due to gravity 9.81ms2 and the density of water 1000 kg/m3 gives a theoretical maximum output of 63kW after friction and generation losses. The actual output will be slightly lower due to the water taken off by the fish pass and various other technical factors.
The local Cooperative Food Superstore buys all our electricity. Any power surplus to its needs is sold through the national grid.
Archie extracts over 70% of the potential power of the site when running at peak generating power (maximum power output). An average annual output of 240 000kWh is our target. This implies a load factor (the ratio of average to maximum output) of 43.5%. By comparison a typical load factor for a well sited modern wind farm would be 30%.