Small hydro potential

摘要

In mature power markets, most opportunities for major new hydroelectric schemes have long since gone. However, small hydro has significant potential. In the United States, the government has estimated that hydro capacity could increase by 70 GW with negligible environmental impact. But even small hydro has local impacts and managing these often undermines the commercial viability of small schemes. Hydro power is an old technology that has come in and out of favor more than once. It harnesses the energy embodied in flows of water, either using the natural run of a river, or by damming a waterway to create a head of water, effectively a pool of potential energy. This is released into an underground, downward-slopping tunnel called a penstock, in which a turbine is located. Capacity depends on the size of reservoir and the drop in elevation to the turbine.