spacer.gif (883 bytes)
WIND ENERGY WEEKLY Vol. 18, #851, 10 June 1999


A recent study at the University of Wisconsin-Madison finds that wind farms have a high "energy payback" (ratio of energy produced compared to energy expended in construction and operation), and that wind's energy payback is higher than that of coal and nuclear. The study, sponsored and publicized by the Energy Center of Wisconsin and undertaken by a team of researchers at the University of Wisconsin-Madison, compared the energy payback and carbon dioxide (CO2) emissions of power generation for wind farms, coal plants and nuclear reactors. In the study, three Midwestern wind farms were found to generate between 17 and 39 times as much energy as is required for their construction and operation, while coal plants generate on average 11 and
nuclear plants 16 times as much. The study is the first to use one consistent payback calculation method in order to facilitate comparison between different methods of
power generation. The method used compares the amount of electricity that the plants are expected to generate with the total energy required over the plantís lifecycle. Among items included as energy required in production are: mining and transporting coal or enriching uranium fuel, fabricating power plant materials such as steel and concrete, building and operating the plants, dismantling the plants at the end of their
life spans, and storing hazardous waste. 

The study also compared CO2 emissions from the three energy sources.  Predictably, those from nuclear and wind power generation are minute compared to those from coal. Coal plants, the study said, emit approximately 974 tons of the gas per million kWh of electricity generated. Nuclear power plants indirectly emit about 15 tons per million kWh, primarily because of the fossil fuel energy needed to mine and enrich uranium fuel, while wind indirectly emits about 14 tons per million kWh because of the energy used in building and maintaining towers and turbines.

The study contributes new data, and a new method, to a growing body of research documenting the low costs and high benefits of wind energy compared to conventional sources of power generation. The Energy Center of Wisconsin is a non-profit organization that sponsors and undertakes research in efficient use and management of
energy, and makes that research available to Wisconsinís energy service consumers and providers. ECW members include Wisconsin electric and gas utilities, the Public Service Commission of Wisconsin, the University of Wisconsin, and public interest groups. More information about the study is available from the Centerís Web site at 

Wind Energy Weekly Archives | AWEA Home Page

© 1999 by the American Wind Energy Association.
May be freely distributed provided this notice is included.
All other rights reserved.