Source takepart.com
The U.S. Department of Energy estimates that the nation could increase its hydroelectric capacity 50 percent by 2050 without building new dams. Rather, the new capacity would come from upgrading existing hydropower facilities with more efficient technology and by constructing hydropower storage facilities that pump water uphill into reservoirs during off-peak hours, when electricity is cheap. When demand and power prices spike, the water is released downhill through turbines to generate electricity.
Such a strategy could grow hydropower capacity from 101,000 megawatts to 150,000 megawatts by 2050, according to the report.
From our very good friends over at takepart. com