Wind generation on land is affected by several factors, such as the topography of the surrounding area, temperature, competing land uses, and human activity. Due to the unevenness and diversity of topographical areas in the U.S., certain areas are not able to harness large amounts of wind energy. Mountainous areas, as well as large ridges inhibit the movement of air, limiting the wind’s power. However, recent advancements in offshore wind technology offer the prospect of unlocking the massive energy potential of offshore wind.
Wind flows virtually uninterrupted over the ocean, without mountains, forests, or other obstacles to impede it. This means that the potential energy from offshore wind turbine farms have much higher power generation rates. In fact, due to the downward movement of air across the ocean’s surface being replaced at a higher rate than on land, offshore wind farms have a much higher energy capacity. The U.S. The Department of Energy estimates that offshore wind has the potential to generate at least 2,000 GW per year. Merely capturing a small percentage of this potential energy could pay huge dividends as the U.S. seeks to shift towards more renewable forms of energy.
Innovative technologies in both the U.S. and around the world have risen to the challenge of harnessing this massive amount of energy. The recently unveiled Haliade-X 12 MW offshore wind turbine solves both the scalability problem for harnessing offshore wind, as well as the low capacity factors of most land-based wind turbines. The Haliade-X possesses a 60 to 64 percent capacity factor, able to generate up to 40 percent more power than any current turbine in the U.S. wind industry. The state of Connecticut has also awarded a contract to the Park City wind energy project, an 804 MW project that is slated to go online in 2025 and provide 14 percent of Connecticut’s energy needs.
Other U.S. states have led the way in developing innovative solutions to the problem of anchoring turbines to the ocean floor. Anchored offshore wind turbines are usually confined to shallow seas, as the costs of building a turbine for depths greater than 16 feet are cost prohibitive. In the state of Maine, the Aqua Ventus utilizes floating turbines developed by the University of Maine that are attached to the bottom of the ocean by mooring lines secured to the seabed. These deepwater turbines allow for the harnessing of much stronger ocean winds far from the shore. An alternate current (AC) cable is used to join the turbines together, while an undersea power cable will carry the generated electricity to a mainland transfer point.
These innovations in energy capacity and adaptability have allowed wind energy to increase its share of the U.S. energy grid. However, as is the case with most renewable sources of energy, transportation of that energy to consumers has historically been an obstacle. Offshore wind generation provides a potential breakthrough. Nearly 80 percent of U.S. electricity demand occurs in coastal states or states surrounding the Great Lakes, which is also where most Americans reside. Furthermore, offshore wind turbines have the potential to account for land-based turbine weaknesses. Offshore winds are usually stronger during the day, coinciding with when energy demands are highest. At night, energy demands are lower, which would allow land-based turbines to provide adequate amounts of energy.
Continued innovation in offshore wind development may well position coastal states as major producers and beneficiaries of wind energy. Innovation for offshore turbines has continued to push capacities higher by scaling up turbine size, increasing power outputs by redesigning vertical axis turbines to capture more wind, and decreasing the amount of space turbines take up. The U.S. stands to continue to reap the rewards of innovative approaches to offshore wind energy and should continue to support public, private, and joint partnerships to further develop offshore wind energy projects.
Written by Roy Mathews, Public Policy Associate
The Alliance for Innovation and Infrastructure (Aii) is an independent, national research and educational organization. An innovative think tank, Aii explores the intersection of economics, law, and public policy in the areas of climate, damage prevention, energy, infrastructure, innovation, technology, and transportation.