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Wind power is one of 47 ways in which America can reduce greenhouse gas emissions, according to a new US government report issued on Earth Day. "Technology Opportunities to reduce US Greenhouse Gas Emissions" pinpoints clean energy as a "pathway" or solution available in the near term, meaning over the next decade.

The report, by the directors of the US Department of Energy's 11 laboratories -- including the National Renewable Energy Laboratory -- is a response to President Clinton's 1997 demand that the country "invest more in the technologies of the future." It recommends a wide range of technologies for maximum flexibility and least risk. It also suggests the country start soon to aggressively develop the needed basic science and technologies -- including wind.

Apart from wind, the near-term "pathways" include electric hybrid vehicles, high efficiency lighting, super insulating windows, and passive solar heating and cooling of buildings. In the mid to longer term are fuel cells for transportation, broad use of biomass fuels, and hydrogen fuelled systems. Carbon-reducing technologies are grouped into three areas -- energy efficiency, clean energy and carbon sequestration (removing carbon from emissions and/or enhancing storage of carbon, in, for example, aquifers).

In the first decade, the report says there should be significant advances in energy efficiency -- and that carbon sequestration technology should begin to emerge. Beyond 2025, it says the impact of research based advances in clean energy technologies should begin to exceed the carbon reduction of end use efficiencies. And in the third decade, carbon sequestration would begin to add a serious third dimension to the package of solutions.

Major carbon offsets

Wind power systems are described as "very close" to cost competitive on a levelised basis of $0.04-$0.07/kWh. They are hampered though, as are other renewables, by uncertainties in electricity restructuring. Even so, major carbon offsets could be achieved in 34 of the 50 US states with high quality wind resources. Larger market penetrations in the mid to long term require an even lower cost and increased reliability. To achieve this a better understanding of wind flow, aerodynamics, structural dynamics and advanced power conversion devices is needed as well as development of durable and lightweight structural devices.

In the near term, up to one fifth of a region's electric supply could be from wind without adverse operating or economic effects. But greater penetration would need modification of systems operation, hybrids with other technologies, energy storage, transmission and infrastructure, and improved wind forecasting. Bird fatalities are negligible, it concludes, with proper siting in areas of fewer birds.