Humans have been harnessing water power for thousands of years, but in the past century, advancements have made water an integral part of the energy mix in the U.S. From hydropower to the new frontier of marine energy, here are five things you should know about water power.

1. Water power is the oldest and newest renewable

Did you know that hydropower projects are in just about every state? Hydropower is a foundational part of our energy infrastructure and, as America's original renewable, has powered the country for over a century. It accounts for about 6% of the nation’s electricity, and offers many benefits like swimming, boating, fishing, camping, and hiking, in addition to generating renewable energy for American homes and businesses. 

Marine energy, the newest frontier in water power, has the potential to generate electricity for millions of homes from predictable and consistent waves and tides along our coasts. Since marine energy is an early-stage market, the Water Power Technologies Office (WPTO) makes investments supporting key technology innovations to harness this new frontier of energy.

2. Hydropower plays a major role in maintaining the reliability and the resiliency of the U.S. power grid

Hydropower has long been the nation’s largest source of renewable electricity, providing not only baseload energy, but energy storage and essential services to the electric grid. In short, hydropower is the ultimate grid stabilizer — it quickly delivers power after an outage, addresses peak demands, and maintains proper voltage levels and frequencies across the grid, which are all necessary to ensure our energy security. Also, because hydropower can act like a battery by storing energy, it’s complementary to other forms of generation such as wind and solar. Hydropower makes sure power supplies stay constant.

5 Things You Should Know About Water Power
The Azura wave energy device at the U.S. Navy's Wave Energy Test Site in Hawaii
Northwest Energy Innovations

3. Marine energy can revitalize infrastructure along our coastlines

Marine energy is an emerging science and technology sector, with potential to stimulate new industry opportunities, create jobs, and increase manufacturing. Just this year, the Energy Department announced its partnership with Oregon State University to build a world-class wave energy testing facility in the coastal community of Newport, Oregon. This new facility can test up to 20 wave energy converters, allowing smaller nearby ports to take advantage. For example, the Port of Toledo can leverage its maritime resources to support the manufacturing and maintenance of marine equipment needed for the test site. Marine energy can be a source of economic revitalization to communities across the United States as the industry grows.

4. There’s room for more hydropower and pumped-storage hydropower (PSH)

36 gigawatts (GW) of it, in fact. The U.S. PSH fleet provides 97% of our nation’s utility-scale storage—all generated from 42 plants across the country. Because PSH has the ability to function as a battery and integrate variable renewable energy or excess electricity from base-load sources such as coal or nuclear, more storage like it is needed to support the grid. Additionally, U.S. hydropower could still grow from 101 GW to nearly 150 GW of combined electricity generation and storage capacity by 2050. It will do this by unlocking untapped hydropower resources. WPTO is funding early-stage research on new, transformative PSH designs that would improve sustainability and environmental performance and shorten development timeframes for new facilities.

5. Marine energy has the potential to provide power in remote locations

By converting the energy of waves, tides, river, and ocean currents into electricity, marine energy technologies have the potential to provide cost-effective energy for remote or coastal areas military bases and smaller communities —where electricity costs are high from a reliance on imported fuels. Marine energy can also assist with a number of distributed ocean applications, including charging for ocean-based sensors and underwater vehicles, and non-electric uses like desalination-- the process of removing salt from seawater. These opportunities could more rapidly allow industry to develop and reduce technology costs in the near term while providing domestic energy independence from imported fuels.

DOE's Office of Energy Efficiency and Renewable Energy (EERE) supports early-stage research and development of energy efficiency and renewable energy technologies that make energy more affordable and strengthen the reliability, resilience, and security of the U.S. electric grid. Visit to learn more about the Water Power Technologies Office.



Sarah Wagoner
Contributor page for Sarah Wagoner, former Communications Specialist for the Water Power Technologies Office.
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