For well over a century, hydropower has been a reliable, low-cost, clean component of America’s electricity portfolio.  It powered the nation through the Great Depression and helped fuel our war effort during World War II, becoming a mainstay of economic growth and national security. 

Today, in an era of concern over climate change and emissions, hydropower is an integral part of the solution to address climate issues and increase renewable energy generation.  It supplies over half of America’s renewable electricity, a critical resource that is responsible for avoiding over 200 million metric tons of carbon pollution each year.    

Moreover, hydropower provides base load power critical to integrating greater amounts of intermittent renewable energy sources like wind and solar into the electricity grid.  And “pumped storage” – energy that is stored by pumping water to a higher elevation reservoir that can be released when energy is needed – constitutes the vast majority of the nation’s current energy storage capacity, which is critical in balancing other intermittent renewable resources and ensuring grid reliability.

Hydropower facilities can quickly go from zero power to maximum output, making them exceptionally good at meeting rapidly changing demands for electricity throughout the day.  Long project lifespans and zero fuel costs provide electricity at low-costs to tens of millions of Americans from coast-to-coast.  Requiring nothing more than the flow of moving water, hydropower does not produce air pollution or toxic byproducts.

Every state in the country gets electricity from hydropower.  While hydropower is certainly a critical resource in the Northwest, states like Alabama, New York, North Carolina, Tennessee, and Arizona are among the top ten hydropower producing states in the nation. 

For all of these reasons, environmental advocates like the Union of Concerned Scientists and the Nature Conservancy support the further development of environmentally-responsible hydropower.

And despite what many think, there’s room for hydropower to grow. A 2010 study done by Navigant Consulting found that 60,000 megawatts (MW) of new hydropower capacity could be added in 15 years with the right policies in place.  Much of this development would not require the construction of new, large water infrastructure.

For example, even though most people think "dams" when they first hear "hydropower", the two are not one in the same.  Only three percent of the nation’s 80,000 dams currently generate electricity.  We could increase our generating capacity by over 12,000 MW through the addition of power generation to the nation’s non-powered dams, according to a report by the Department of Energy.  That’s equivalent to constructing about 12 nuclear power plants.  

Now a new movie called DamNation has begun appearing at environmental film festivals, presenting an unbalanced assessment of hydropower, urging the removal of dams without any sense of context or their many benefits, and in particular, ignoring the important role hydropower plays in reducing carbon emissions.

There are certainly dams in the United States that are candidates for removal for varying reasons.  But, just as the film admits, it would be “economically foolish” for us to tear down all the dams.  Rather, just as we should examine some antiquated dams for removal, we should also work to maximize the public benefit of the many current dams that don’t generate hydropower but are needed for other reasons.

Policymakers and responsible environmental advocates have in fact been looking to hydropower to meet our nation’s energy and environmental challenges by maximizing the public benefit of existing water infrastructure.

Last year the Congress unanimously passed, and President Obama signed into law, a bill that seeks to expedite licensing for building hydropower on the nation’s non-powered dams.  The bill was not only supported by the hydropower industry, but also American Rivers, the nation’s leading conservation organization dedicated to protecting and restoring America's rivers.

Policymakers recognize that hydropower is a unique solution to the nation's energy and environmental challenges.  So does the public.  A recent survey found that 81 percent of Americans believe that the existing hydropower fleet should be maintained and 75 percent support expanding hydropower.

And more can be done to encourage this type of development.  Finding additional efficiencies in the regulatory process, providing certainty to developers through long term extension of tax incentives, and investing in continued research and development which has not only lowered the cost of many hydropower technologies, but also increased their environmental performance, are essential policy initiatives to unlock hydro’s untapped potential and to meet our energy and climate challenges.

Hydropower has been the backbone of America’s renewable energy history, and will be an integral part of our future.  After examining its energy, environmental, and economic benefits, it’s no wonder hydro has such strong support from the public and policymakers alike as part of a diverse, secure electricity portfolio.

Ciocci is executive director of the National Hydropower Association.