Florida's Missing Winds -- New Evidence Supports the Viability of Harnessing Offshore Wind Energy in Florida
In 2010, a wind energy resource map produced by the National Renewable Energy Laboratory (NREL) showed no wind off of Florida, Alabama and Mississippi (Chart 1). The NREL report excluded sections offshore Florida, Alabama, and Mississippi due to insufficient pre-study data.
|Chart 1: U. S. Offshore Wind Energy Resource Map (NREL 2010). Florida, Alabama, and Mississippi are "blanked out" due to lack of prior study data.|
However, there are other promising reports for wind energy potential off the coast of these regions. In fact, offshore wind power will be an important component of a future renewable energy portfolio. Florida's coastal cities and broad shelf of shallow water offshore favor the development of an offshore wind energy industry.
A different 2008 National Renewable Energy Laboratory (NREL) publication depicts Florida contributing 5-10 gigawatts of wind power capacity by 2030, comprised of a small amount of onshore and a relatively large amount of offshore wind farms (Chart 2).
|Chart 2: State contributions to wind energy providing 20% of U.S. electrical power by 2030 (NREL 2008)|
The discrepancy between the two NREL studies bring to question why one report predicts Florida to supplying a significant share of wind power while another report lacks enough data for a wind resource map. The irregularity is based in the science of resource assessment. With modern wind turbines reaching heights of 85m and projected to increase to 100m over the next two decades, it is challenging to assess a resource where there are no consistent measurements. Most of the offshore wind measurements in the Gulf of Mexico and Florida's Atlantic coast are from widely scattered buoy and coastal platforms with wind measurement heights at 5-10 m with a few at 30-40 m; both well below the heights of modern offshore wind turbines. Furthermore, coastal sea breeze and pre- and post-frontal wind patterns can be complex, containing low-level wind jets that are not resolved by
the current network of surface observations. NREL's "20% Wind by 2030" estimate came from a climate "reanalysis" modeling study and Navigant's assessment came from a University of Delaware graduate student course project. A preliminary study of offshore buoy and tower data by FSU's Center for Ocean-Atmospheric Prediction Studies (COAPS) indicates that estimates of offshore winds at 100 m turbine levels are very close to the 7 m/s (15.5 mph) value considered economically viable by NREL, with capacity factors of 25-31%. An accurate evaluation of Florida's wind resource is critical before we can kick-start a wind energy industry in Florida. Georgia is already ahead of Florida in this regard, with the Georgia Institute of Technology investigating offshore wind energy potential with offshore measurement towers supported by the Southern company. A comprehensive wind resource assessment would incorporate remote sensing (e.g. Doppler Lidar to get near the 100 m level of wind turbines), marine wind measurements from tall towers, coupled ocean-atmosphere modeling techniques, and detailed flow models. Furthermore, since tropical cyclones are a risk factor, advanced hurricane risk modeling will be needed to help specify wind turbine engineering design factors related to wind loading.
Two other studies are support the 2008 NREL findings. A recent report by Oceana, an ocean conservation organization, estimates wind energy potential on Florida's offshore Atlantic coast as 10.3 gigawatts, enough to supply 16% of electrical generation. Consistent with this report is a study by Navigant Consulting, sponsored by the Florida Public Service Commission (PSC). The study suggests that although onshore winds tend to be weaker in Florida due to lack of terrain and open prairie spaces, Florida is surrounded by a robust offshore wind resource. Offshore wind is desirable since wind farms may be positioned in relatively shallow water offshore adjacent to coastal electrical load demand centers of major metropolitan areas, but far enough to be unseen from the coast.
Dr. Mark Powell, a NOAA scientist stationed at the Center for Ocean-Atmospheric Prediction Studies (COAPS) and IESES research partner, recently gave a seminar at FSUon the viability of offshore wind energy in Florida and the Gulf of Mexico region. The presentation included a discussion of current fuel sources, advantages and limitations of wind energy, preliminary indications of the offshore wind energy resource for Florida and the Gulf of Mexico, and research needed to support the development of a sustainable offshore wind energy industry in the U.S. Download the presentation. The Center for Ocean-Atmospheric Prediction Studies (COAPS) is a center of excellence performing interdisciplinary research in ocean-atmosphere-land-ice interactions to increase our understanding of the physical, social, and economic consequences of climate variability. See the COAPS fact sheet on Wind Power. Dr. Mark Powell is an IESES research partner.