Recognizing North Carolina’s wind-energy potential

Earlier this summer, the online retailer Amazon announced its plans for a large-scale wind energy facility in northeastern North Carolina. The $400 million project will include 104 wind turbines and generate the equivalent of electricity needed to power 61,000 homes annually. The project expects to be operational in late 2016 and represents the first of its kind in the state and the South.

For land-based wind projects, the future is clearly now. The project also illustrates the significant wind resources available in North Carolina – both on land and offshore. While an offshore wind farm may not be in the state’s immediate future, recent policy developments and ongoing research confirming the significant potential of offshore wind resources continue the momentum for offshore sites down the road.

Within the last year, the U.S. Department of Interior asked for the public to comment on the environmental effects of its plan to open up more than 300,000 acres off the North Carolina coast to wind energy development. The request for comments followed action by the agency in 2014 to designate three specific areas off of North Carolina for potential wind energy development – one area off the state’s northeastern coast and two near Wilmington.

The federal government’s designation increases the likelihood of wind energy projects off the N.C. coast. The designations also confirm what offshore wind energy experts have known for years: North Carolina has some of the best wind resources in all of the East Coast.

In 2009, at the request of state officials, University of North Carolina at Chapel Hill researchers evaluated the state’s offshore wind resources. Researchers spent nine months looking at wind resources, ecological risks and use conflicts, and existing transmission infrastructure. The study concluded that “because of a promising wind resource, large areas off the coast of North Carolina are well-suited for wind energy development and worthy of further investigation.”

Scientists have continued to refine the research to build on the findings of the 2009 report. Re-examination suggests that over the continental shelf, especially north of Cape Hatteras, wind resources are richer than previously thought. The explanation is a bit non-intuitive: Cool ocean waters in these areas lead to weakened winds right above the surface of the ocean where wind measurements are typically made, but they can produce significantly stronger winds at the height of wind turbines.

Further offshore, over the Gulf Stream where warm ocean water persists, the opposite occurs – winds near the ocean surface are noticeably enhanced, but wind speeds at turbine height are somewhat less than previously estimated. Because shallower waters are required for wind farms, these findings suggest the wind resource offshore of North Carolina, which already appears to be among the best on the Eastern Seaboard south of New England, deserves serious consideration.

In addition to evaluating the wind resource, scientists are examining the effect of wind turbines on the ocean bottom. Researchers at the UNC Institute of Marine Sciences have partnered with the National Oceanic and Atmospheric Administration to survey the natural hard-bottom habitat in one of the two areas designated for potential wind power development off Wilmington. Hard-bottom is considered essential fish habitat by fisheries scientists and regulators. Divers have been surveying the seafloor as a means of determining whether the base of a wind-turbine would enhance the abundance and production of valuable reef fishes like snapper and groupers.

Reassuringly, the research reveals that artificial hard-bottom habitat, such as artificial reefs and shipwrecks, is widely used by snappers and groupers in patterns that imply that reef fish production may be elevated by placing large rocks on the seafloor to dampen scour around wind turbine bases.

The planned development of the Amazon wind farm in Perquimans and Pasquotank counties represents a major step forward for the wind energy industry in North Carolina today. Recent policy developments and research findings also make clear that our state may see similar activity and plans for offshore wind energy projects soon.