Energy Sources

Hydro

Facts

There are three broad classes of hydroelectric power generation: impoundment, diversion and pumped storage. Impoundment facilities typically involve storing river water in a dam. Diversion redirects the flow of all or a portion of a river through a desired location. A pumped storage facility pumps water from a low reservoir to a higher one to store potential energy when power prices are low or “off-peak.”

Source: "Fueling the Future- Better Ways to Use America’s Fuel Options," Consumer Energy Council of America, May 2006

Overview

Worldwide, hydropower plants have a combined installed capacity of 857 gigawatts and produce more than 3,119 terawatt-hours of electricity annually.

Source: EIA: http://tonto.eia.doe.gov/cfapps/ipdbproject/iedindex3.cfm?tid=2&pid=33&aid=7&cid=regions&syid=2008&eyid=2008&unit=MK

Use of hydropower currently provides the energy equivalent of 5 million barrels of oil per day, and only 33% of the world’s potential hydropower resources have been developed, with most remaining potential in developing countries. Hydropower currently offsets 2.1 billion tons of CO2 each year and could potentially offset 7 billion tons more if its remaining potential is tapped.

Source: International Hydropower Association

Source: “Hydropower’s contribution.” UNFCCC: http://unfccc.int/cop9/se/present/taylor.pdf

Hydroelectricity and other grid-connected renewable generation sources will be the fastest-growing source of electricity between now and 2030, although hydro is expected to grow at a slower pace than other renewables, such as solar and wind. By 2030 renewable sources of energy will account for 23% of electricity generation worldwide.

Source: "International Energy Outlook 2010," Energy Information Administration

Worldwide, hydropower accounts for 19% of generating capacity.

Source: “International Energy Outlook 2010.” Energy Information Administration

Around 99% of Norway’s electricity comes from hydroelectric sources, while Iceland obtains approximately 79%, Canada 69% and Austria 59% from hydroelectric sources. Brazil, the largest energy market in Central and South America, obtains approximately 87% of its electricity from hydro.

Source: Energy Information Administration; available: http://www.eia.doe.gov/emeu/cabs/Brazil/Electricity.html

Source: Orkuveita Reykjavikur; World Energy Council

Updates from EIA

China's Three Gorges Dam is about 1.4 miles (2.25 kilometers) long and 607 feet (185 meters) tall. It is five times larger and provides twenty times the power of the famous Hoover Dam in the US southwest.

Source: National Geographic News

Hydropower represents the largest proportion of renewable energy Clean Development Mechanism (CDM) projects, accounting for over a quarter of all CDM projects. The majority of the projects are in China, with China and India combining to account for three quarters of the world’s hydro CDM projects.

Source: International Hydro Association

The expansion of renewable energy, which includes hydro, is expected to increase from 9.9% of total delivered energy in 2007 to 13.3% in 2030 (or a 2.6% average annual percent rise), an amount greater than the percentage expansion of natural gas (1.3%) and coal use (1.6%). Much of the growth in renewable energy is expected to come from the completion of large hydroelectric facilities in non-OECD Asia.

Source: "International Energy Outlook 2010," Energy Information Administration

Because of environmental objections and regulatory and legal hurdles, new hydro facilities have become much more expensive and virtually impossible to set up in many developed countries. In the United States, most opportunities for installing hydropower are small, 85% are rated at less than 30 megawatts. However, small installations are subject to the same licensing procedures as large ones, meaning that investors get less energy per dollar in licensing and regulatory fees.

Source; “U.S. Looks to Hydropower as an Untapped Power Source”; San Francisco Chronicle; available: http://www.sfgate.com/cgi-bin/article.cgi?f=/g/a/2009/07/16/hearstmaggreen397387.DTL

There is no conclusive method for measuring GHG emissions from hydropower. Unlike thermal power plants, no GHG emissions are released from hydropower. However, the creation of freshwater reservoirs needed for hydropower plants generates land use changes that affect overall GHG levels. The UN is currently conducting a study that will allow for full monitoring and measurement of freshwater reservoirs so as to quantify the true emissions savings from these hydro plants.

Source: International Hydro Association

Hydro: Opportunities

Hydro is a clean, reliable alternative.

Wind and solar energy are intermittent sources of electricity, meaning that their output at any given time varies depending upon environmental factors. Hydroelectric dams, due to their storage capacity, provide a constant and relatively reliable source of power and could be the backbone of a cleaner and more renewable electric grid.

Hydroelectric power is cheap and clean.

Once facilities are built, hydroelectricity is less expensive and cleaner in comparison with electricity generated from oil or natural gas

Hydro: Challenges

Hydropower becomes unreliable during droughts

Most large rivers have already been harnessed for power in developed countries. Hence, there have been few large hydroelectric projects in recent years. Moreover, this power source is subject to droughts in places with variable precipitation.

Hydropower is untapped.

Although 30,000 megawatts of potential hydropower remains untapped in the US in the form of small existing plants and potential generation at 76,500 non-hydropower dams, it is extremely difficult to obtain approval for further development of hydropower. There is potential for 2,200 megawatts to be built by 2025, about the same as three nuclear power plants.

Source: “U.S. Looks to Hydropower as an Untapped Power Source”; San Francisco Chronicle; available: http://www.sfgate.com/cgi-bin/article.cgi?f=/g/a/2009/07/16/hearstmaggreen397387.DTL