Is hydropower more efficient than other producers of electricity?
Hydro power has often been a byproduct of dams built as flood control measures. The average output is often as low as 10% of the peak, because it depends on rainfall. No rain upsteam = no hydro power. If the upstream rivers are prone to silting, regular dredging is needed to remove the silt from the dam reservoir. If we define efficiency as output power over total stored energy, hydro power is pretty efficient Nuclear power is used through a steam (rankine cycle) and like coal or oil fired systems that is generally under 40% efficient. Wind turbines have a theoretical maximum efficiency of 56.
“Efficient” with respect to what? If it’s pure energy conversion efficiency, then it’s pretty good. Even small home hydropower systems easily attain 50% efficiency. If it’s economic efficiency, then it is really good since it requires little maintenance and the maintenance that it does require is quite inexpensive. If it’s environmental efficiency, then it’s pretty good as well. There are few waste products and fuel transport is nil. The effects on wildlife and stream sedimentation seem to be the biggest objections.
