<Tr> <Td> 7 </Td> <Td> The Dalles Dam </Td> <Td> 1957 </Td> <Td> 2,038 </Td> </Tr> <P> The Rampart Dam was a proposed 5000MW project to dam the Yukon River in Alaska for hydroelectric power . The project was never built and laws would need to be changed for this project to be built . </P> <P> According to a United States Department of Energy report, there exists over 12,000 MW of potential hydroelectricity capacity in the US existing 80,000 unpowered dams . Harnessing the currently unpowered dams could generate 45 TWhr / yr, equivalent to 16 percent of 2008 hydroelectricity generation . </P> <Table> Hydroelectric generation in the United States <Tr> <Th> Year </Th> <Th> Summer capacity (GW) </Th> <Th> Electricity generation (TWh) </Th> <Th> Capacity factor </Th> <Th> Yearly growth of generating capacity </Th> <Th> Yearly growth of produced energy </Th> <Th> Portion of renewable electricity </Th> <Th> Portion of total electricity </Th> </Tr> <Tr> <Td> 2017 </Td> <Td> 80.06 </Td> <Td> 300.05 </Td> <Td> 0.428 </Td> <Td> 0.2% </Td> <Td> 12% </Td> <Td> 43.7% </Td> <Td> 7.47% </Td> </Tr> <Tr> <Td> 2016 </Td> <Td> 79.91 </Td> <Td> 267.81 </Td> <Td> 0.383 </Td> <Td> 0.3% </Td> <Td> 7.50% </Td> <Td> 43.9% </Td> <Td> 6.57% </Td> </Tr> <Tr> <Td> 2015 </Td> <Td> 79.66 </Td> <Td> 249.08 </Td> <Td> 0.357 </Td> <Td> 0.56% </Td> <Td> - 4.0% </Td> <Td> 45.77% </Td> <Td> 6.11% </Td> </Tr> <Tr> <Td> 2014 </Td> <Td> 79.24 </Td> <Td> 258.75 </Td> <Td> 0.373 </Td> <Td> 0.05% </Td> <Td> - 3.66% </Td> <Td> 47.93% </Td> <Td> 6.32% </Td> </Tr> <Tr> <Td> 2013 </Td> <Td> 79.22 </Td> <Td> 268.57 </Td> <Td> 0.387 </Td> <Td> 0.64% </Td> <Td> - 2.78% </Td> <Td> 51.44% </Td> <Td> 6.61% </Td> </Tr> <Tr> <Td> 2012 </Td> <Td> 78.7 </Td> <Td> 276.24 </Td> <Td> 0.401 </Td> <Td> 0.06% </Td> <Td> - 13.50% </Td> <Td> 55.85% </Td> <Td> 6.82% </Td> </Tr> <Tr> <Td> 2011 </Td> <Td> 78.65 </Td> <Td> 319.36 </Td> <Td> 0.464 </Td> <Td> - 0.23% </Td> <Td> 22.74% </Td> <Td> 62.21% </Td> <Td> 7.79% </Td> </Tr> <Tr> <Td> </Td> <Td> 78.83 </Td> <Td> 260.2 </Td> <Td> 0.377 </Td> <Td> 0.39% </Td> <Td> - 4.85% </Td> <Td> 60.88% </Td> <Td> 6.31% </Td> </Tr> <Tr> <Td> 2009 </Td> <Td> 78.52 </Td> <Td> 273.45 </Td> <Td> 0.398 </Td> <Td> 0.76% </Td> <Td> 7.31% </Td> <Td> 65.47% </Td> <Td> 6.92% </Td> </Tr> <Tr> <Td> 2008 </Td> <Td> 77.93 </Td> <Td> 254.83 </Td> <Td> 0.373 </Td> <Td> 0.05% </Td> <Td> 2.96% </Td> <Td> 66.90% </Td> <Td> 6.19% </Td> </Tr> <Tr> <Td> 2007 </Td> <Td> 77.89 </Td> <Td> 247.51 </Td> <Td> 0.363 </Td> <Td> 0.09% </Td> <Td> - 14.43% </Td> <Td> 70.18% </Td> <Td> 5.95% </Td> </Tr> <Tr> <Td> 2006 </Td> <Td> 77.82 </Td> <Td> 289.25 </Td> <Td> 0.424 </Td> <Td> 0.36% </Td> <Td> 7.00% </Td> <Td> 74.97% </Td> <Td> 7.12% </Td> </Tr> <Tr> <Td> 2005 </Td> <Td> 77.54 </Td> <Td> 270.32 </Td> <Td> 0.398 </Td> <Td> - 0.13% </Td> <Td> 0.71% </Td> <Td> 75.57% </Td> <Td> 6.67% </Td> </Tr> <Tr> <Td> </Td> <Td> 77.64 </Td> <Td> 268.42 </Td> <Td> 0.395 </Td> <Td> - 1.33% </Td> <Td> - 2.68% </Td> <Td> 76.36% </Td> <Td> 6.76% </Td> </Tr> </Table>

Hydroelectricity provides about 7 percent of the electricity generated in the united states