Offshore energy alternatives explored

www.luminanews.com
July 30, 2009

Under pressure to examine alternative energy sources the state's advisory subcommittee on offshore energy exploration, in an expanded scope of research, heard presentations to harness wave action and wind energy in lieu of drilling for oil or natural gas at a panel meeting held Tuesday, July 28 at the University of North Carolina Wilmington (UNCW).

Chaired by UNCW chancellor emeritus Dr. James Leutze and Environmental Defense Fund chief oceans scientist, Dr. Douglas Rader, the panel of scientists, engineers and policy makers convened to accelerate its agenda: making recommendations on these matters to the General Assembly to meet a preliminary deadline in mid-September.

The panelists heard from Steve Kopf, hydrokinetics expert who catalogued a sampling of wave and water devices designed to generate electricity. Some are suitable for deepwater, the nearshore surf zone and others for rock face, headland or jetty. One converts the heaving motion of wave swells into energy; another similar device, a moored buoy, floats mounted on a stable spar.

While an offshore buoy farm might appear on the surface to be suitable for the North Carolina coast the merits begin to diminish with the disruption of the bathymetric contour of the ocean's bottom and the natural rhythm of sediment transport that impacts sensitive coastal beach processes like erosion and the accretion of sand near inlets.

"Sediment transport is a big issue," Kopf said. "Anytime you're extracting energy the energy gets reflected and can actually reduce erosion where it is and cause erosion somewhere else." Most of the options Kopf introduced are still in the study stage. "There's this great promise but right now the reality is that it's very much in a test phase."

The possibility of threats to delicate marine animal and plant ecologies, impacts on commercial and recreational fisheries notwithstanding, plus the potential disruption of service during hurricane and tropical storm events, the transmission of power to shore via AC cable presents yet another challenge. While Kopf was able to deliver a flavor of the industry, it seemed apparent that hydrokinetic energy solutions were not a fit for North Carolina waters because the demand for more energy during the summer months does not match the highest wave activity which typically occurs during the winter months.

"One thing we're really trying to focus on is that resource in phase with demand. The East Coast has a moderate resource," Kopf said, "not that this part of the world won't ever see wave energy development it's just that developers, like early wind developers, are focusing on where the resource is the strongest."

Pete Peterson, UNC Chapel Hill marine science professor distilled that argument even further in his presentation on the appropriateness of harnessing offshore winds as an energy alternative. Peterson's wind study, commissioned by the North Carolina General Assembly, was given its first airing on Tuesday.

His evaluation of the state's wind resource, after considering ecological impacts—the risks to birds and bats, marine animals, sea turtles, fish and bottom dwellers; conflicts with commercial and recreational fisheries; navigational aids, like lighthouses; cultural artifacts, like shipwrecks; and the military's fly space, narrowed the target area to Raleigh Bay, south of Cape Hatteras and north of Cape Lookout with the possibility of bringing the energy transmission ashore into Morehead City. "Morehead is where we have a good nexus to get into the power system. That, folks, is the spot to focus on in North Carolina," Peterson said.

Ironically, that area is not far from the potential drilling field. Though without resolution of submerged land issues, private use of public resources, leasing agreements, strategic assessments, amended acts and appropriate permits in place Peterson said the solution would be dead on arrival without a government in place to act on it.