Scale of Hydropower Projects

Head
􀂄Water must fall from a higher elevation to a lower one to release its stored energy.
􀂄The difference between these elevations (the water levels in the forebayand the tailbay) is called head
􀂇Dams: three categories
􀂄high-head(800 or more feet)
􀂄medium-head(100 to 800 feet)
􀂄low-head(less than 100 feet)
􀂇Power is proportional to the product of
head x flow
Large-hydro
􀂄More than 100 MW feeding into a large electricity grid
􀂇Medium-hydro
􀂄15 -100 MW usually feeding a grid
􀂇Small-hydro
􀂄1 -15 MW -usually feeding into a grid
􀂇Mini-hydro
􀂄Above 100 kW, but below 1 MW
􀂄Either stand alone schemes or more often feeding into the grid
􀂇Micro-hydro
􀂄From 5kW up to 100 kW
􀂄Usually provided power for a small community or rural industry in remote areas away from the grid.
􀂇Pico-hydro
􀂄From a few hundred watts up to 5kW
􀂄Remote areas away from the grid.