I started looking at the volume required to power just one house at 12.6 watts per square meter. If you figure an average usage of 29.6 kWh per household per day, and 12.6 watts per cubic meter, that comes to roughly 2350 cubic meters of water per household per day.
To put that in perspective, that's roughly one Olympic sized swimming pool of water for just one household per day.
If that's right, then a river the size of the Potomac with flows between 1 to 2 Billion gallons per day would power about 1500 to 3000 homes.
It's an interesting niche source of energy, but I don't see the density of this energy source making a significant dent in the need for electricity.
antialias_physorg
May 29, 2017(Also rivers are used to dump any number of pollutants - from farm runoffs to human and industry waste. By the time any river reaches the oceans it's by no means an ideal clean watre/salt water system).