Although it is hydro electricity. Which is renewable energy,It has a very small proportion. Including water resources can be developed to generate electricity, there are fewer. And be faced with the opposition of various groups, so it is trying to invent new energy sources cheap and no end. Some are already used as water - water waves (sea) from ocean thermal, solar, wind and geothermal, etc. But there are limits to such development is expensive, time-consuming construction. Some countries have the potential of such energy sources are adequate.