MOREHEAD CITY – North Carolina has a lot of potential for offshore wind energy, according to a Sierra Club forum panel assembled Tuesday night at Carteret Community College.
The North Carolina chapter of the club held an offshore wind energy forum at the college, which drew a crowd of about 170 people. Steve Benbow, a Sierra Club volunteer, said offshore wind may not be the cure-all, fix-all for the state’s energy needs, but he believes it can be a viable source of renewable energy.
Each of the panelists gave a presentation on wind energy as it related to their individual fields of expertise. Brian O’Hara of the N.C. Offshore Wind Coalition, a nonprofit coalition advocating the offshore wind industry in the state, talked about the workings of wind energy turbines.
“Wind turbines work like a fan in reverse,” Mr. O’Hara said. “You have wind turning blades, turning a generator.”
Wind turbines are being actively used in Europe. Mr. O’Hara said as of June 2011, there were more than 4,000 of them installed there, and more are planned for the future.
“It’s clean energy, with nearly zero emissions,” he said. “Offshore wind energy provides well-paying, local jobs. It’s proven technology since 1991. It provides stable-priced energy, because wind is free.”
Globally, wind energy has been tapped into both onshore and off. Mr. O’Hara said compared to onshore wind, offshore is steadier, which means a more reliable stream of energy. He did say, however, that installation costs for offshore turbines run higher than onshore.
To get offshore wind energy to the mainland, cables are run through the seabed. Kristian Bergman, business development manager with ABB Inc., an international energy company, said wind turbines will use alternating current cables if the turbines are less than 50 kilometers (about 31.1 miles) from shore. If they’re more than 100 kilometers (over 62.2 miles), then direct current will be used, along with conversion substations to transform it back to AC, which is what’s used in power grids. If the distance is between those two, then the kind of cable used depends on individual circumstances for each project.
Mr. Bergman said when laying the cable, it’s important to survey the area. Offshore turbine cables are usually buried about 4-5 feet below the seabed, using a special plow that creates a narrow trench that naturally fills back in after the cable’s laid.
If offshore wind energy is developed in North Carolina, then it will be developed in leases in federal waters. Jen Banks, wind energy projects coordinator for the N.C. Solar Center, a clearinghouse for renewable energy programs and projects, said the federal waters start three miles offshore.
“The Bureau of Ocean Energy Management is the lead for leasing waters offshore,” she said. “There’s a bit of a race to be the first state with offshore wind.”
Ms. Banks said the BOEM forms state task forces to choose areas suitable for offshore wind energy. In North Carolina, the bureau has about 500 leasing blocks offshore.
Ms. Banks said there’s a lot of activity in North Carolina regarding offshore wind. Among the projects exploring offshore wind is the Governor’s Scientific Advisory Panel on Offshore Energy. Ms. Banks said the panel looked at the potential for offshore energy in 2011 and should be coming out with a report sometime soon this year.
UNC-Chapel Hill conducted a study on offshore wind energy in 2009 at the request of the General Assembly. The study showed 311 lease blocks with good offshore wind energy potential.
Dr. Pete Peterson, distinguished professor of marine sciences, ecology and biology at UNC Institute of Marine Sciences in Morehead City, was one of the lead scientists on that study. Dr. Peterson, who was also a panel member, said his team’s role in the study was to look at environmental and human use conflicts.
Dr. Peterson’s team studied the use of the coastal area in North Carolina by marine animals, including birds. People at past public meetings have raised concerns about the potential for birds to be hit by wind turbines.
Dr. Peterson said his team found the areas closer to land tended to be used by birds, as well as the capes off North Carolina. The Gulf Stream is an area of tremendous importance to marine life as well.
Dr. Peterson said his study showed that the bird density in the areas being looked at for wind turbines is much smaller than the typical density at working grassland wind farms. However, he said the fact that birds are typically actively flying offshore should also be taken into consideration.
“We need to get a turbine in the water to know for sure (the risk),” he said.
Dr. Peterson spoke favorably about developing wind energy off North Carolina. He said offshore wind energy produces no emissions, which would lead to reduced greenhouse gasses that cause climate change. While offshore oil and natural gas drilling is also being considered in North Carolina’s federal leases, Dr. Peterson said its risky.
“Drilling off North Carolina is in deep water on sloping ground,” he said. “North Carolina would benefit to wait and see how other states do drilling in similar conditions.”
Studies have shown some of the best areas for tapping into offshore wind are off the coast of Carteret County, and Morehead City makes a good potential hookup point to the state’s power grid. Glenn Carlson, chief commercial officer for business and economic development for the N.C. State Ports Authority, said the Morehead City Port is a prime location for turbine part delivery.
“Our single limitation is the need for a mobile heavy lift crane,” he said. “This investment would be justified by the jobs created.”
Mr. Carlson said the state ports are economic engines not just for the cities they’re in, but also the state as a whole. Morehead City’s port is a good delivery point due to its deep waters, open access to the ocean and lack of any overhanging features.