CHARACTERISTICS

Most countries around the world have some existing hydropower capacity, and many countries rely heavily on hydropower for baseload electricity generation. Worldwide, hydropower supplies about one-fifth of the world's electricity; in countries or regions where hydro resources are plentiful, hydro supplies as much as 70% of electricity requirements.

Many hydro sites have been in use for several years. At many of these sites, modernizing and upgrading turbines and generators will increase their efficiency and/or electrical output. Also, many have not been designed to maximize the full capacity of the site. Additional equipment and/or equipment upgrades may be able to take advantage of this potential without requiring the construction of new dam capacity.

Maximizing hydropower generation, which is baseload generation, can divert the need for capacity from other, fossil baseload electricity sources, and thereby reduce greenhouse gas emissions overall. Also, in countries where existing facilities may be facing relicensing, some capacity may be lost due to new, stricter requirements. Maximizing capacity at other sites may help to offset potential adverse environmental impacts.

SIZE:
Upgrades to date have increased efficiency from 1-20%. (20% improvement was from a 1905-vintage machine). Adding generation capacity has increased size to as much as 165% of original design capacity.

FEATURES:
Operating efficiency is typically from 85-90%. Capacity factors vary from 20-90% depending on the variability in streamflow.

COST:
N/A because is too site-specific.

CURRENT USAGE:
As of 1993, 20% of global electricity was generated by hydro; It is estimated that increasing efficiency by 1% in the U.S. alone would result in an additional 3.3 billion kWh from hydropower.

POTENTIAL USAGE:
In the U.S., there is the potential for an additional 21.3 GW through increasing efficiency or generation of existing hydropower (existing U.S. capacity, including pumped storage, is almost 92 GW).

ISSUES ASSOCIATED WITH IMPLEMENTING ACTION

• Availability of resources is site specific and may not be located close to demand centers.
• Small incremental gains in capacity, efficiency, and energy production through modernization and upgrading of turbines and generators may not be enough to justify the cost of facility upgrades.
• Public may have misperceptions that increasing efficiency at existing sites may adversely impact aquatic life and habitat. Also, in some areas, the public has levied pressure on dam and reservoir operators to increase non-power flows. Public education programs highlighting energy, environmental and recreational benefits and implications of new operating conditions may be necessary.
• Regulatory uncertainty as to relicensing procedures and impact on capacity and costs during the processing period creates uncertainty for economic projections, which can jeopardize financing for improvement projects.
• Equipment changes may require amendment of the original license.

CLIMATE CHANGE IMPACT

EMISSION EFFECT:
    

CONDITIONS FOR EMISSIONS MITIGATION:

• Hydropower produces no GHG emissions. Environmental impact may occur due to land-use or siting issues.

EMISSION ESTIMATE:
Produces no greenhouse gas emissions. In the U.S., in 1997, hydropower generation avoided the release of 83 million metric tons of carbon equivalent.

COST-EFFECTIVENESS:
$25-38/ton of net CO₂ avoided

SECONDARY EFFECTS:
Produces no air pollutants.

RESOURCES

• A pump-turbine upgrade program undertaken at the jointly owned (Jersey Central Power & Light/Public Service Electric & Gas) Yards Creek Station consisted of replacement of the runners, wicket gates, and associated components, along with other modifications, to improve efficiency, capacity, performance, regulating capability, and longevity. Upgrade of the first unit increased its capacity by 20 MW and its cycle efficiency by 9%.
• Several U.S. utilities are increasing capacity and/or efficiency at existing sites including: Tennessee Valley Authority (Chickamauga and Nickajack reservoirs), New York Power Authority (Robert Moses Plant), American Electric Power, and others.

CONTACTS

U.S. Hydropower Council for International Development
Debby Stone
Director, Trade Promotion
Washington, DC
Tel: (202) 383-2550
Fax: (202) 383-2555

National Hydropower Association
Washington, DC
Tel: (202) 682-1700
Fax: (202) 682-9478
hydroinfo@hydro.org
http://www.hydro.org

U.S. Department of Energy
Paul Carrier
Office of Electricity and Generating Fuels Policy for Hydropower Policy and Regulation
Washington, DC
Tel: (202) 586-5659
http://www.doe.gov

U.S. Department of Energy
Ron Loose
Director for Hydropower R&D
Wind, Hydro, Ocean Technology
Washington, DC
Tel: (202) 586-8086
http://www.doe.gov