Buzz around renewables includes solar and wind power, energy storage, and sometimes green hydrogen and nuclear power. But there is a reliable older technology that is contributing to reducing our carbon footprint: hydropower.

Dams in the United States

Dam building was a 20th-century venture in the United States. Currently, there are over 90,000 dams in the United States, and only about 2500 of them generate power. They provide about 7 percent of electricity and 38 percent of the electricity from renewable resources. That means there is a lot of potential for retrofitting existing dams with hydroelectric power generators.

Not all dams are suited to generating power. Many don’t store enough water, or they are too remote to be a meaningful power source. According to a Department of Energy report, thousands could be retrofit and could add 12,000 megawatts of generation capacity. In addition, upgrading existing hydropower dams and retrofitting canals will also provide additional power.

Retrofitting Dams Has Support

Even though hydropower retrofits produce a smaller amount of energy, they still offer benefits to the power grid. According to Tim Welch, manager of the hydropower program at the DOE, small hydropower projects can help regulate the grid and make it more resilient.

Environmentalists support the move, as long as the dams being retrofit are not ones that should be removed to improve the ecosystem. Retrofitting existing dams has much less environmental impact compared to building new dams and conservation groups acknowledge hydropower’s role in mitigating climate change by decarbonizing the grid. There is also agreement that retrofits play a role in dam maintenance by providing an incentive to keep the dam in shape.

There is political support for retrofitting dams, and several federal bills include plans to overhaul the country’s dam infrastructure. These bills were shaped by an alliance between the hydropower industry and the environmental groups that are keeping an eye on them.  The bill’s aim of retrofitting, rehabilitating, and removing dams, called the 3Rs, is made more urgent by the drought in the western states. The funding for these projects and incentives is currently part of the overall infrastructure bill that is stuck in Congress.

Drought Impacts Hydroelectric Power

The drought in the western states impacts hydropower generation when water levels are too low to generate electricity, especially in California. Hydroelectric generation in the first four months of 2021 was 37% lower than in 2020, and 71% lower than in 2019. When hydropower is not available, it is replaced with natural gas power which is more expensive and adds to pollution.

While hydropower is less viable in some places, like the West coast, using it where the water is still flowing is one more piece of the renewable energy puzzle.