Survey of Energy Resources 2007
Wind Country Notes
United States of America
The Energy Information Administration (EIA) estimates that the raw wind resource potential of the US is in excess of 3 000 GW. This estimate excludes offshore areas, areas with poor wind potential (average annual wind speeds less than 7 m/s), areas with specific legal or technical restrictions on development for wind use (such as areas with high slope, environmentally restricted areas and urban areas), and areas greater than 20 miles from existing transmission lines. However, most of the land included in this estimate is likely to be precluded from wind development for economic reasons not explicitly accounted for in the estimate, such as high land costs, rough terrain, lack of site access, aesthetic or environmental limitations, the need to upgrade or expand existing transmission capacity in order to accommodate remote wind capacity, or the need to provide energy storage or back-up generation in order to maintain grid reliability.
The American wind power industry has shown remarkable progress, increasing by an average 29% each year between 2000 and 2005. By end-2005 capacity stood at 9 149 MW and by end-2006, the American Wind Energy Association estimates that it stood at 11 603 MW. Of the states that had installed capacity at end-2005, 15 possessed more than 100 MW each. New capacity added during the year represented about 52 projects in 22 states (averaging 1.5 MW per turbine). The Department of Energy's (DOE) Wind Powering America project aims, by 2010, to have at least 30 states with more than 100 MW.
The Advanced Energy Initiative launched in February 2006 is providing the stimulus to sustain and further the progress of the US wind power industry. Whilst wind power currently only supplies approximately 0.3% of total electricity generation, the Initiative states that 'areas of good wind resources have the potential to supply up to 20% of the electricity consumption in the United States'.
The Federal production tax credit (PTC) has had a significant role in the growth of wind power. There has been a distinct correlation between the years when the US$ 0.019/kWh credit (for the first 10 years of production) was applied and the expansion of capacity. In those years when the credit lapsed (2000, 2002 and 2004) there was only a small incremental amount of capacity. The 2005 Federal Energy Policy Act (EPAct) extended the PTC to end-2007 when it is due to expire again.
Other federal incentives (depreciation deductions, loans, grants, financial and technical assistance) and state programs (renewable energy purchase mandates, green pricing, tax and investment incentives, net metering etc.) are all designed to ensure the continued growth of the industry. Looking forward, the DOE's Wind Energy Program has three aspects to its R&D: it is studying firstly, low-wind-speed turbines for deployment in the vast areas of US territory that possess less than optimal wind speeds; secondly, the areas suitable for wind installations sited, initially in shallow offshore waters and then in deeper offshore waters. It has been estimated that the US has in excess of 1 000 GW offshore potential lying between 5 and 50 nautical miles from the coastlines (including the Great Lakes), with about 810 GW in waters that are 30 m or deeper; and thirdly, the launch (in 2006) of SeaCon. The SeaCon (sea-based concept studies) initiative will concentrate on innovative technologies such as combining wind turbines with electrolysers to produce hydrogen, combining wind and hydropower technologies and the use of wind energy to provide power for municipal water and wastewater operations.