Earlier this month, North Carolina Gov. Bev Perdue released a comprehensive study on the state's potential for offshore energy, including the pros and cons of developing offshore wind power.
The report, prepared by the governor's Scientific Advisory Panel on Offshore Energy, contains the findings of a 2009 feasibility study of developing commercial-scale wind power in the Pamlico and Albemarle Sounds and in the coastal ocean of North Carolina, and also includes updates from developments learned over the past few years.
Among the report's findings was that North Carolina has the best offshore wind resource on the U.S. East Coast, accounting for 26% of the total East Coast resource in an area of less than 30 meters of water. According to the National Renewable Energy Laboratory (NREL), if the entire resource were to be developed with a 42% average capacity factor, it would meet the annual electricity demand of every coastal state from Florida to Maine.
That estimate, however, does not take into account how much of that area can be developed, nor does it consider the many hurdles to developing wind power off North Carolina's coast.
According to the study, there are 506 developable federal lease blocks off the North Carolina continental shelf in waters with depths of less than 40 meters. Each of these lease blocks represents an approximately three-mile by three-mile area, which equates to 4,554 square miles available for wind power development.
The risks
The study identifies a number of areas in which offshore wind development off North Carolina could pose ecological and human-use conflicts.
Bird behavior, in particular, could be problematic, as passerine birds migrate at night. However, a study conducted by North Carolina-based utility Duke Energy showed that half of the bird species native to the area never flew as high off the water as the minimum height swept by a standard 3.6 MW wind turbine.
Notably, although water birds are abundant in the sounds, no endangered avian species would be affected by the addition of offshore wind turbines, the study says.
However, other species – such as sea turtles and humpback whales – that live in the potential development zones are listed as threatened or endangered under the federal Endangered Species Act, and could be affected by the noise and electromagnetic fields from offshore wind turbines.
Despite these potential conflicts, some synergies exist between offshore wind development and the area's ecosystem. For instance, wind turbines are typically secured to the seabed with an anti-scour apron made of rock, which, in turn, creates a habitat for rocky-reef fish.
Another mutual benefit, according to the report, is that the presence of a wind farm would cause ships to avoid certain areas in which species usually suffer from the harmful effects of ship traffic.
The panel's report also cites a study by the University of North Carolina that found that training flights, radar communications and submarine detection make large areas off the state – especially in Onslow Bay – incompatible with offshore wind energy development. Heavily fished areas where bottom dredging or trawling is practiced could also pose dangers to buried transmission cables, the study found.
Logistical and regulatory hurdles
Like in many other states, as well as at the federal level, red tape burdens North Carolina's potential for offshore wind development.
"Existing North Carolina law presents significant legal and regulatory barriers to permitting wind energy development in state coastal waters," the panel's report states. "The existing state-level statutory framework for the issuance of submerged-lands leases has gaps as they relate to wind energy projects, and various regulatory issues may impede development of wind energy in state waters."
Additionally, as with many other wind projects – both onshore and offshore – one major barrier to offshore wind development in North Carolina is the lack of adequate transmission to bring the energy produced by the generation facilities to end users.
Because North Carolina lacks the coastal population density of many other East Coast states, offshore wind farms would require significant transmission upgrades to deliver the power to customers.
According to the panel's study, Dominion North Carolina's transmission system would only be able to accommodate about 10 MW of offshore wind capacity without upgrades. Progress Energy Carolina's grid would be accommodate up to 250 MW of offshore wind energy generation at Morehead City or Wilmington without major upgrades; however, much of this area has been deemed undevelopable due to wildlife and human-use conflicts.
According to the report, the transmission upgrades necessary to accommodate 3 GW of offshore wind capacity would require an investment of between $525 million and $1.31 billion.
The rewards
Not taking into account the necessary transmission upgrades, however, North Carolina is the cheapest state in the nation in which to develop offshore wind energy, with costs estimated to be between 20% and 25% lower than in other East Coast states, according to a report from the Energy Information Administration.
The carbon-reduction potential for offshore wind development is substantial, including in North Carolina. According to the panel's study, a small inshore farm with 30 3.6 MW wind turbines would be equivalent to removing 550,000 vehicles off the road over the project's 20-year lifetime, and a large offshore farm with 450 3.6 MW turbines would be equivalent to displacing one year's emissions from 9 million cars or from 12 coal-fired power plants over a 20-year period.
Developing offshore wind farms would also benefit the state by adding job opportunities and workforce development programs for the wind energy supply chain, as well as by giving the state revenue obtained from offshore wind leases and wind-related tourism.
Furthermore, North Carolina's investor-owned utilities must comply with a renewable portfolio standard of 12.5% by 2021 – which may be difficult to achieve without offshore wind power.
The recommendations
In its report, the governor's panel made several recommendations for offshore wind development in the state. First, they said, North Carolina should streamline its regulatory procedures with the appropriate statutes, rules and regulations that "foster and encourage appropriate offshore wind development consistent with concerns for the coastal environment and communities."
The state should also facilitate the development of the transmission infrastructure necessary to interconnect offshore wind farms, they said.
The state – and the governor, in particular – also needs to "engage with the industry to attract to North Carolina a wide range of supply-chain facilities and jobs associated with the emerging wind energy industry," they added.
Furthermore, the panel recommended that the state create a program for research and data collection in order to ensure there is adequate information to evaluate the impacts of offshore energy exploration and energy development, and suggested that North Carolina engage in comprehensive ocean and coastal resource management to ensure the sustainable use of ocean and coastal resources.
All considered, the panel found that although there are still major challenges in the development of offshore wind farms off the North Carolina coast, the rewards trump the risks.
"The disadvantages associated with development of commercial wind farms off the coast of North Carolina do not outweigh the advantages," the panel concluded.
