A new study has found that the size of the nation’s wind resources may be up to three times more than previous estimates, meaning that the contiguous 48 states have the potential to generate up to 37 million gigawatt hours annually. The study, which was conducted by the National Renewable Energy Laboratory (NREL) and AWS Truewind, shows the total energy yield that could be generated using current wind turbine technology on the nation's windy lands. To put the study’s findings in perspective, the DOE points out that total U.S. electricity generation from all sources was roughly 4 million gigawatt hours in 2009.
The study reflects substantial advances in wind turbine technology that have occurred since the department’s last national wind resource assessments in 1993. For example, previous wind resource maps showed predicted average wind speeds at a height of 50 meters, which was the height of most wind turbine towers at the time. The new maps show predicted average wind speeds at the 80-meter height of today's turbines. Because wind speed generally increases with height, turbines built on taller towers can capture more energy and generate more electricity.
The new estimates also incorporate updated capacity factors, reflecting improvements in wind turbine design and performance, according to the DOE.
The updated numbers are relevant to the needs of the wind industry and lawmakers, says Michael Brower, AWS Truewind's chief technical officer: “We believe they will provide critical support to state and federal policy makers working to stimulate wind energy development in the United States.”
Although much of the country’s wind potential comes from the breezy central regions, many eastern and western states have substantial wind potential, and 35 states have 1,000 megawatts or greater potential, the study says. State-by-state estimates are available here.
Jennifer Goodman is Senior Editor, Online for EcoHome.