This blog entry was written by Allie Brown, former Clean Energy Advocacy Manager at SACE.Guest Blog | October 9, 2014
Today, SACE is releasing a new analysis, called Advanced Wind Technology: Elevated Opportunities for the South, showing that the South is the next frontier for wind energy. Our conclusion is based on analysis of new turbine technology, as well as several case studies of wind turbines that reveal a promising future for Southern wind farms.
New wind turbine technology is a game changer for wind energy opportunities in the South. In just five years, wind turbines have greatly evolved to be more suitable across the region. Wind turbine hub heights ranging from 360-460 feet (110-140 meters) are now available for wind developers. Taller turbines and longer blades are capable of capturing more wind, which results in harnessing more electricity and reducing costs. One modern 2 megawatt wind turbine can now power approximately 600 homes a year!
Modern wind turbines make wind energy economically feasible in more areas across the Southeast. Now with access to winds at greater heights, Louisiana, Mississippi and Tennessee each contain more than 25,000 megawatts (MW) of wind energy potential, and a total estimated 134,000 MW of wind potential now exists within the Southern region. To put that number into perspective, that’s about half as much of the total installed electric utility capacity in the Southeast!
This advancement in technology has led to lower costs for wind power. Wind energy is now one of the least expensive sources of new power generation in the country. Costs have declined by 39% over the past decade for wind speed areas averaging 6 meters per second (13.4 miles per hour), which applies to many areas in the Southeast.
Our analysis additionally shows that while the Southeast is now ready for wind energy development, popular wind speed maps do not always reflect this great potential. The coarse wind resource assessment maps that may be used to initially assess a site for wind farm development are often not accurate enough to identify ridge top wind resources. Particular sites that may be suitable for wind power development can be characterized as “low wind speed” areas according to resource assessment maps if they average the wind speed of surrounding, lower wind speed areas. Our new analysis looks at case studies of wind development projects that show actual performance much greater than one would assume based on coarse resource assessment maps.
One such case study that provides a great example of underestimated wind speed potential is the Southeast’s first and currently only wind farm, Buffalo Mountain. Located in Oak Ridge Tennessee, the modern portion of the Buffalo Mountain wind farm was constructed in 2004 and contains 15 wind turbines. The wind farm has been successful, producing enough electricity to power 3,400 homes a year. By looking at the the National Renewable Energy Laboratory (NREL) 80-meter wind speed map (below), it appears the Buffalo Mountain site would only achieve an annual average wind speed of 4.0-5.0 meters per second (8.9-11.2 miles per hour). While difficult to gauge, this is the most accurate prediction that can be made with this resource.
Yet, by using data from the wind farm, an accurate estimate of the average wind speed can be determined. Based on production of the wind farm, the annual average wind speed is approximately 6 meters per second (13.4 miles per hour). Actual output at the Buffalo Mountain Wind Farm is at least double what would be expected using the NREL map with the estimated wind speed. And, while Buffalo Mountain has performed to expectations, the addition of modern turbines with taller hub heights would greatly expand the wind farm’s electricity generation.
It’s important to understand that wind speed maps alone cannot predetermine the viability of a wind farm. In order to get accurate measurements, a meteorological tower or anemometer (a wind measurement device) needs to be installed to collect wind measurements for one to two years. There is still a strong need for updated resource assessment maps with taller hub heights that more accurately reflect wind energy opportunities in the region.
SACE’s full report, titled “Advanced Turbine Technology: Elevated Opportunities for the South,” can be viewed here.