Hydroelectric System Efficiencies
Efficiency here refers to the rate which the hydro system converts the energy it receives into usable electricity. Hydroelectricity systems are among the most efficient of all renewable electricity generation technologies, typically running at more than 50%, even going as high as 90% (compared to just 10%-20% for solar PV). The efficiency of some larger systems may be as high as 95%.
Keeping the system well maintained is vital if you want to get the best efficiency from your system.