Hydropower relies on the gravitational force of flowing water, usually from a dammed body of water, to spin a turbine and generate electricity. In addition to the low Co2 output, hydropower is consistent and efficient. Hydropower has become the most-used form of renewable energy, accounting for approximately 20 percent of the world’s electricity in 2006; hydro has no carbon emissions, and is both renewable and sustainable. See all Hydro Members
Hydropower Usage and History
According to the U.S. Department of Energy, hydropower facilities in the United States can generate enough power to supply 28 million households with electricity, the equivalent of nearly 500 million barrels of oil. The current total U.S. hydropower capacity, including pumped storage facilities, is about 95,000 megawatts. Researchers are working on advanced turbine technologies that will not only help maximize the use of hydropower, but also minimize adverse environmental effects.
The use of hydropower to generate mechanical energy dates back hundreds of years to early saw and grain mills. In the 1800′s many Vermont dams were built to harness water’s power for saw and grain mills, with settlement patterns following rivers for this reason. The late 1800’s saw new dams being built, and old ones converted to pair running water with electrical generators, as the first hydroelectric power plants came on line in Vermont and throughout America.
By 1920, 40 percent of U.S. electric needs were being met by hydroelectric sources. Then-gigantic projects like the 1,345 Megawatt Hoover Dam have since been dwarfed by global projects, the latest and largest being the Three Gorges Dam in China, with a production capacity of 22,500 Megawatts. Here in Vermont, most municipal utilities in the northern portion of our state were built around the creation of a hydropower plant in town. Many projects in Vermont are now more than 100 years old, requiring only refurbishment of the turbines and generators every 30 years.
Hydroelectric generation in Vermont
Presently Vermont has 84 operating hydroelectric plants. They are distributed throughout the state, and are owned by public and private utilities, electric co-ops, companies and individuals. The plants have a total generating capacity of 190 megawatts (MW), and produce on average 12 percent of Vermont’s KWH load.
In addition there are several large projects on the Connecticut River, presently owned by a Canadian firm, which sells the electricity to southern New England. These dams could provide an additional 6 percent of Vermont’s KWH load. Recently many Vermont utilities renewed a long-term contract to import hydropower from Hydro Quebec. This will provide about 25 percent of Vermont’s KWH load. Although the Hydro Quebec projects are quite large, with installed capacities of thousands of MW, it should be recognized that Quebec is our neighbor and part of our ecosystem.
Community Scale Hydropower
By and large all existing dam sites in Vermont have already been developed, with no new projects commissioned since 1993. Environmental concerns, a burdensome licensing process and difficult economics have been primarily responsible for the lack of new dams coming on line. There are, however, several dam sites that are working toward becoming operational in the next few years. There are also possibilities for Community Scale small projects, particularly at Municipal water supply systems, and lake outflows. Community scale hydro projects, especially “streaming,” or ‘run of the river’, hydropower (which allows rivers to run their natural course) are one alternative to the utility-scale dam projects. Streaming hydro also brings the production of electricity closer to consumers, reducing efficiency losses incurred during transmission across long-distance power lines.
Learn More About Hydropower
- Download REV’s Hydro Power Educational Factsheet (pdf)
- Union of Concerned Scientists Hydro page
- Why Hydro Power’s outline of hydropower
- Take a detailed hydropower tour
- Vermont Electric Power Producers, details of non-utility projects in Vermont
- Union of Concerned Scientist’s “How Hydroelectric Works” page
- US Department of Energy, Energy Efficiency & Renewable Energy, Wind & Water Program
Some people oppose dams because they change the flow of rivers and affect the migrating patterns of fish and other species, but aren’t they also a great renewable energy source?
Hydroelectric dams are among the greenest and most affordable electricity sources in the world — and by far the most widely used renewable energy sources — but they also take an environmental toll in the form of compromised landscapes, ecosystems and fisheries.
President Barack Obama has committed $32 million to modernize existing hydropower dams, increase efficiency and reduce environmental impacts.
“There’s no one solution to the energy crisis, but hydropower is clearly part of the solution and represents a major opportunity to create more clean energy jobs,” U.S. Secretary of Energy Steven Chu told reporters last year. “Investing in our existing hydropower infrastructure will strengthen our economy, reduce pollution and help us toward energy independence.” (E/The Environmental Magazine)