April 28, 2015 | By Barbara Vergetis Lundin

The U.S. Department of Energy (DOE) has released the first-ever report to quantify the current size, scope, and variability of hydropower supplies in the United States.

Credit: DOE

According to the report, hydropower provides approximately seven percent of the U.S. electricity supply -- enough to power more than 20 million homes -- and has experienced significant growth industry-wide. Within the last decade, the industry has supported more than 55,000 direct domestic jobs across the country, and helped offset 200 million metric tons of carbon emissions per year, equivalent to the emissions from more than 42 million passenger vehicles.

"This report outlines the diversity of our nation's hydropower fleet, shows its tremendous contribution to the U.S. clean energy mix, and points to promising future growth," said Assistant Secretary for Energy Efficiency and Renewable Energy David Danielson at the National Hydropower Association Annual Conference. "With an expanding industry and continued investment, hydropower remains one of our nation's most cost-effective and reliable sources of renewable energy and provides an important tool for boosting our clean energy supply."

Hydropower can be rapidly integrated with other renewable energy sources into the electric grid -- contributing to the administration's goal of doubling the nation's renewable energy supply again by 2020. The 2014 Hydropower Market Report highlights how, including a critical investment of more than $6 billion throughout the last decade to strengthen the existing hydropower fleet, as well as the economic benefits that have resulted from support of the industry. 

Today, the report says, the hydropower manufacturing supply chain spreads across 38 states, with more than 170 companies producing one or more of six major hydropower components: turbines, generators, transformers, penstocks, gates, and valves.

Aside from the hydropower that is benefitting the United States, there is more than 77 gigawatts (GW) of hydropower potential that remains untapped, the report notes. 

An assessment by the DOE's Oak Ridge National Laboratory (ORNL) assessed the ability of existing non-powered dams across the country to generate electricity. The 80,000+ non-powered facilities represent the vast majority of dams in the country; more than 90 percent of dams are used for services such as regulating water supply and controlling inland navigation, but lack electricity-generating equipment. The study found that the nation has more than 50,000 suitable non-powered dams with the technical potential to add about 12 GW of clean, renewable hydropower capacity. The 100 largest capacity facilities could provide 8 GW of power combined. Power stations can likely be added to many of these dams at a lower cost than creating new powered dam structures. Together, these facilities could power millions of households and avoid millions of metric tons of carbon dioxide emissions each year.

By making use of existing water resources and infrastructure, the vast majority of new hydropower projects built over the last decade have added electric generating equipment to dams that were previously not powered. The current hydropower development pipeline contains a diverse mixture of projects proposed at non-powered dams, conduits, and previously undeveloped rivers and streams, the report says.

Hydropower plays a key role in providing flexibility to the nation's power grids, allowing utility operators to quickly fulfill spikes in electrical demand -- such as those caused by summer heat waves -- making hydropower a vital asset to many states' energy portfolios. Further expanding this system flexibility, more than 50 pumped-storage hydropower projects, which function as large energy storage systems for other clean energy sources, are in the various stages of planning and development and will add strength and stability to our electric grids, according to the report.

For more:
- see the report

http://www.fierceenergy.com/story/report-first-quantify-us-hydropower-supplies/2015-04-28