Of the many natural gifts we can appreciate on Earth Day, it's hard to think of one more versatile—or more vital—than water. In addition to nourishing life on this planet, water is our oldest source of renewable electricity: some of the nation's hydropower dams date back more than 100 years.

Hydropower dam with greenery surrounding it and mountains in the background.
This Earth Day, we acknowledge some of the successes of the U.S. Department of Energy Water Power Technologies Office.
Pablo McLoud

At the same time, water is central to new energy approaches, from marine technologies to methods for storage on the electric grid. These water power technologies are essential to reducing the greenhouse gas emissions that cause climate change and helping achieve a 100% clean energy economy. Through firm power sources like hydro and predictable sources like tidal, these technologies can also help ensure a reliable, resilient electric grid.

Here are seven ways the U.S. Department of Energy's Water Power Technologies Office (WPTO) is supporting hydropower and marine energy innovation for an equitable clean energy future.

1. Strengthening Hydropower Resources

Hydroelectric generation currently accounts for 41% of the nation's renewable energy. Many of these hydropower plants can store water to produce electricity when it is most needed, delivering both clean power and crucial flexibility.

To safeguard and improve hydropower's ability to provide grid reliability and resilience, WPTO established the HydroWIRES initiative in April 2019. HydroWIRES aims to fill research gaps in understanding the past, present, and future value of hydropower, including what new technology is needed to expand hydropower's ability to meet grid needs.  

2. Supporting Wind and Solar on the Grid

Pumped storage hydropower represents a whopping 95% of grid-scale energy storage in the United States. While this will change as battery storage grows, pumped storage remains an important energy resource that can be dispatched when output from solar or wind energy resources is lower.

Through the HydroWIRES initiative, researchers have developed new approaches to designing and configuring pumped-storage hydropower projects, while reducing costs and potential environmental impacts. One of these projects—Oak Ridge National Laboratory’s Ground-Level Integrated Diverse Energy Storage (GLIDES) project—involves low-cost, modular pumped storage that can be installed anywhere, potentially filling the gap between small-scale battery installations and large pumped-storage hydropower facilities.

PNNL Testing Campaign Verifies Fish Passage Performance of Natel Energy’s Restoration Hydro Turbine

PNNL testing campaign verifies fish passage performance of Natel Energy’s restoration hydro turbine.

3. Protecting Marine and River Environments

We have only begun to understand and implement strategies for harnessing the power of the ocean as a source of clean energy. The Triton initiative, which is led by Pacific Northwest National Laboratory’s Marine and Coastal Research Laboratory, explores technologies for more precise and cost-effective monitoring of acoustics, animal interactions, electromagnetic fields, and other impacts on the environment. The goal is to ensure that any marine energy development is done with minimal impact to surrounding ecosystems.

Other work WPTO supports focuses on river environments: The HydroPASSAGE project, for example, has developed tools to reduce fish injury and mortality, including monitoring of fish passage at Washington State's Ice Harbor Dam. Low-impact hydropower can help mitigate the ecological and cultural impact of hydropower by considering ecological flow, water quality, upstream and downstream fish passage, shoreline and watershed protection, endangered and threatened species, cultural and historical resources, and more.

4. Forging New Paths to Clean Water

Desalination is an important tool for providing access to clean drinking water. However, it can be energy intensive, and facilities tend to be stationary, which limits uses for disaster relief and remote coastal communities.

Supported by WPTO and National Renewable Energy Laboratory (NREL), the Waves to Water Prize is accelerating the development of small, modular, wave-powered desalination systems for such disaster relief and recovery scenarios, as well as in water-scarce coastal and island locations.

The five-stage, $3.3 million contest is currently in the CREATE Stage, and teams have 180 days to de-risk their technology by building prototypes and/or individual subsystems. They will also develop a plan to finalize and deliver their technologies for the final stage of the prize, DRINK. As part of the competition, the competitors will have a unique opportunity to collaborate with external organizations that are supporting their innovations.

5. Encouraging Future Innovators

Solving today's energy challenges with water involves tackling complex problems across a variety of disciplines. However, the marine energy and hydropower industries require new talent to support workforce needs and spur innovation.

Under the most aggressive scenario, the U.S. hydropower workforce could grow to 120,000 jobs by 2030 and 158,000 by 2050. To fuel this expansion in water power jobs, NREL has launched Science, Technology, Engineering, and Math (STEM) and workforce development portals for marine energy and hydropower.

WPTO also sponsors the Marine Energy Collegiate Competition (MECC), which launched in 2020 and engaged more than 100 students across diverse disciplines. Stay tuned for the results of this year's MECC, in which 17 teams will create market research-supported business plans for next-generation marine energy technologies.

6. Protecting Coastal Communities

Marine renewable energy can also be used to power ocean observing technologies. The Powering the Blue Economy™: Ocean Observing Prize, a joint prize between WPTO and the National Oceanic and Atmospheric Administration’s (NOAA’s) Integrated Ocean Observing System invites innovators to develop autonomous, wave-powered hurricane monitoring systems that can help protect coastal communities from dangerous storms. The DESIGN Contest phase of the competition recently concluded with 7 winners.

The winning DESIGN Contest teams submitted their concepts for self-charging autonomous vehicle systems that can patrol the seas and collect data that can help predict storm severity. The contenders now advance to the BUILD Contest, where they will develop a functioning prototype for tank testing. Winners of the BUILD Contest will advance to the final stage of the prize, SPLASH, where competitors will test their prototypes out at sea. Up to three grand prize winners will share a total prize pool of up to $1.5 million.

Verdant launch on the NYC East River.

In October 2020, Verdant Power installed three tidal power turbines with its new TriFrame mount at its Roosevelt Island Tidal Energy site in New York’s East River.

7. Pioneering U.S. Tidal Energy

In New York City’s East River, the first commercially licensed tidal power project in the United States is in the pilot phase. For the Roosevelt Island Tidal Energy (RITE) project, project manager Verdant Power has installed three hydropower turbines in the river’s East Channel, a tidal strait connecting the Long Island Sound with the Atlantic Ocean and the New York Harbor. The turbines can generate 105 kilowatts of grid-connected power, and over the first 180 days had 100% uptime and exceeded power predictions with over 160 megawatt hours generated. 

Part of ensuring the success of this milestone tidal energy project is to make sure the turbines can be maintained properly over its lifetime. In the spring, Verdant is conducting a “retrieve and replace” operation to demonstrate its maintenance strategy. The team will deploy a turbine rotor with three thermoplastic blades manufactured by NREL. NREL will be measuring the loads on the blades over a period of 6 months, after which they will be evaluated to investigate the effects of seawater on the blade materials.

Learn more about the Water Power Technologies Office and discover how the Powering the Blue Economy Initiative is helping meet the requirements of emerging coastal and maritime markets.