A new study by Emerging Energy Research (EER), an analyst of renewable-energy markets, forecasts substantial growth during the next 10 years for global offshore wind. During the past eight years, offshore wind developed from approximately 70 megawatts (MW) installed to about 1.5 gigawatts (GW) today, but the study expects it to grow to nearly 45 GW by 2020. The study predicts short-term growth to come from European utilities, followed by stronger developments in North America and Asia.

“The global offshore market has been slow to take off due to cost and logistical challenges. Asia and North America are currently looking to Europe for technology and cost benchmarking. Between 2010 and 2020, these two regions will contribute nearly 25 percent of the total new offshore capacity installed worldwide,” said Eduard Sala de Vedruna, EER’s senior wind analyst.

Over the past decade, total global wind power—onshore, near-shore and offshore—has grown at an average annual rate of more than 30 percent. Another record had been set in 2008, with more than 27 GW of new installations, bringing today’s worldwide production to more than 120 GW.

Most current U.S. production is land-based because of rural land availability and strong wind characteristics in the Plains states and in the Great Lakes region. Building transmission infrastructure to get electricity generated by inland wind to coastal cities is expensive due to the distances involved and often a time-consuming, right-of-way quagmire.

Building offshore wind for U.S. coastal cities, however, offers significant advantages, if wind and water conditions are right. Offshore wind speeds tend to be higher and steadier for increased production, and larger turbines can be installed out of site from shore. And, while seabed transmission lines are expensive per mile as compared to land transmission, offshore farms can be built relatively short distances away from densely populated coastal areas.

Much U.S. coastline has potential for wind development, but turbine foundation costs increase rapidly in deeper water. One of the largest offshore areas in the U.S. with shallow water and strong wind is off Cape Cod, Mass. There, Energy Management Inc. has been trying to develop its Cape Wind Project, America’s first offshore wind farm to be built on Horseshoe Shoal in Nantucket Sound. Just miles from the nearest shore, 130 proposed wind turbines could produce up to 420 MW of renewable energy, enough to supply three-quarters of the electricity for Cape Cod and the islands Nantucket and Martha’s Vineyard.

While there has been considerable not-in-my-backyard and environmental opposition to the project, Congress granted the Minerals Management Service (MMS) the authority to review and approve offshore wind projects, including Cape Wind in the Energy Policy Act of 2005. MMS issued Cape Wind a favorable Draft Environmental Impact Statement in January 2008 and a favorable final EIS in January 2009. Cape Wind and American offshore wind developers await a final decision from MMS.