Hydropower: As the U.S. Bureau of Reclamation has suggested, "upgrading hydroelectric generator and turbine units at existing power plants is one of the most immediate, cost-effective, and environmentally acceptable means for developing additional electrical power"
Hydropower has played an important part in the development of this Nation's electric power industry. Both small and large hydropower developments were instrumental in the early expansion of the electric power industry. Thirty to forty years ago, hydroelectric plants supplied as much as 40 percent of the electric energy produced. Although the amount of energy produced by this means has steadily increased, the amount produced by other types of powerplants has increased at a faster rate.
Today, hydropower, including pumped storage, supplies over 10 percent of the electrical generating capacity of the United States. Coal-fired steam generation is the number one source of electricity in the United States. Hydroelectric pumped storage shows up as a negative factor in electricity production as more electricity is used to pump the water to the upper reservoirs than is produced when the pumped-storage units are used to generate electricity. The benefit of pumped-storage is the ability to effectively shift capacity from periods of low energy use to periods of high energy use.
Hydropower is the primary contributor of renewable energy in the United States.
The costs of generating hydropower are the lowest of all sources of electricity
The hydroelectricity currently produced each year in the United States. is equivalent to nearly 500 million barrels of oil. This presently represents a value for existing hydrogeneration of about $9 billion annually.
Hydropower generation is not a contributor to atmospheric emissions, which are a growing problem on both national and global levels.
Hydropower is presently the most efficient way to produce energy with each kilowatt-hour of hydroelectricity being produced at an efficiency more than twice that of any competing energy resource.
Only 3 percent of the around 80,000 existing dams in the United States have hydropower facilities.