The four most common types of renewable energy are solar, wind, hydroelectric and geothermal.
The barrage traps high water creating a head of water, like a hydroelectric dam.
Hydroelectric - This type of power is extracted from the gravitational pull of water falling from a higher source, such as using a waterfall to generate energy.
So did much fertile river valley land, which was exchanged for hydroelectric or irrigation reservoirs.
The idea of combining other sources of clean energy, such as wind, hydroelectric and geothermal, in addition to solar power may well be one way to enhance the benefits of solar energy while addressing some of the problems.