October 14, 2010, 9:31 PM — If wind is ever to be a significant part of the energy equation in this country we'll need to take it offshore -- into the deep oceans. Large offshore wind objects could harness about more than 4,000 GW of electricity according to a massive report on wind energy from the U.S. Department of Energy.
The DOE notes that while the United States has not built any offshore wind projects about 20 projects representing more than 2,000 MW of capacity are in the planning and permitting process. Most of these activities are in the Northeast and Mid-Atlantic regions, although projects are being considered along the Great Lakes, the Gulf of Mexico and the Pacific Coast. The deep waters off the West Coast, however, pose a technology challenge for the near term.
"Although Europe now has a decade of experience with offshore wind projects in shallow water, the technology essentially evolved from land-based wind energy systems. Significant opportunities remain for tailoring the technology to better address key differences in the offshore environment. These opportunities are multiplied when deepwater floating system technology is considered, which is now in the very early stages of development," the report states.
The challenges of offshore wind technologies are immense however. There are a number of issues including:
* Turbine blades can be much larger without land-based transportation and construction constraints; however, enabling technology is needed to allow the construction of a blade greater than 70 meters in length.
* The blades may also be allowed to rotate faster offshore, as blade noise is less likely to disturb human habitations. Faster rotors operate at lower torque, which means lighter, less costly drivetrain components.
* Challenges unique to the offshore environment include resistance to corrosive salt waters, resilience to tropical and extra-tropical storms and waves, and coexistence with marine life and activities