What is
Offshore Wind?

offshore-header.jpg

The Gulf of Maine has some of the strongest wind speeds in the world. Harnessing the steady, year-round winds of the Gulf of Maine could create a reliable and low-cost source of electricity for New Hampshire ratepayers. Offshore wind development in the Gulf of Maine could also reduce greenhouse gas emissions while creating clean jobs and economic opportunities for the local economy.

Learn more about how offshore wind energy works below.

Offshore wind turbines harness the wind to create electricity.

Offshore wind turbines and land-based wind turbines make electricity using the same basic principles. Wind causes the turbine’s blades to spin, powering a generator that produces electricity. Electricity that is produced by offshore wind turbines is brought to shore using underwater transmission cables. Once ashore, the electricity is added to the regional grid. Because almost 40% of the American population lives in a coastal county, offshore wind energy is an efficient way to supply electricity to areas with the highest electricity demand. Electricity may also be used at the site of turbines to generate hydrogen fuel for transport by pipeline or ship.

Offshore wind turbines are very large, usually much larger than wind turbines installed on shore. Larger wind turbines are more powerful and can harness the faster wind speeds that are available at greater heights. The world’s most powerful wind turbine is the Haliade-X model, produced by General Electric. A single rotation of the GE's Haliade-X turbine’s blades could power the average household for two whole days.

A variety of anchoring technologies are used to install turbines into the ocean. Turbines may have a fixed-bottom foundation or a floating foundation. Most fixed-bottom foundations require drilling into the sea-bed to anchor turbines, a process called pile driving. Floating foundations use cable moorings to anchor turbines in place. Cables may be fastened in place by drilling into the sea-bed or using weighted anchors.

turbine base.jpg

Local site conditions, including water depth and sea-bed geology, determine the most suitable turbine foundation for a project. Fixed-bottom technologies are used in shallower waters (<100 meters in depth) but deeper waters require floating turbines.

 

Because Gulf of Maine waters deepen to over 100 meters within a few miles from shore, floating turbines are best suited for the area. Floating turbine technologies are still being researched and developed. Some of that research is slated to take place in the Gulf of Maine as part of the State of Maine’s Floating Offshore Wind Research Array.

Offshore wind turbines can be placed miles off the coast.

Offshore wind turbines are typically sited miles from shore. Turbines placed at greater distances from shore can capture stronger available wind resources. They also create fewer visual impacts and are less disruptive to inshore fishing activities.

State sovereignty of ocean waters typically extends up to three nautical miles offshore. Beyond three miles, the federal government has jurisdiction of the United States exclusive economic zone, which extends 200 nautical miles from shore. Most offshore wind projects that are proposed for US waters are situated several miles off the coast in Federal waters. The State of New Hampshire has the authority to review federal activities affecting land use and natural resources in New Hampshire's coastal zone to ensure that they are conducted in a manner consistent with New Hampshire Coastal Program’s enforceable policies.

The visibility of offshore wind projects in the Gulf of Maine would be determined largely by the project’s siting and distance from shore. Offshore wind energy in the Gulf of Maine would likely occur up to 10 to 40 miles offshore, in federal waters rather than state waters. Many other factors, including lighting and atmospheric conditions, affect visibility over a landscape. Visual and cultural impacts of offshore wind projects are considered during the environmental review and permitting process.

0001.jpg

Offshore wind development on the Atlantic Outer Continental Shelf is a growing industry.

First developed in Europe over 30 years ago, the offshore wind industry is now in full development in the United States. Although there are only two operational offshore wind farms in US waters (the Block Island Wind Farm and the Coastal Virginia Offshore Wind Farm both owned and operated by Ørsted U.S. Offshore Wind), there are many proposed offshore wind projects that are currently being reviewed for development. These projects are at various stages of the federal permitting process. The map to the left shows active lease areas held by offshore wind energy developers on the Atlantic Outer Continental Shelf. Explore current offshore wind energy activities in US waters by state or by lease area on the Bureau of Ocean Energy Management's (BOEM) website.

Offshore wind projects undergo extensive State and Federal review before authorization.

The Bureau of Ocean Energy Management (BOEM) is the federal agency that regulates offshore wind development in federal waters. BOEM is responsible for identifying areas that may be suitable for offshore wind activity on the Outer Continental Shelf (OCS), conducting reviews of proposed offshore wind projects, and issuing leases and permits to energy developers. The review, leasing, and permit processes for offshore wind projects can take several years. Many other federal agencies are involved in the offshore wind development review process, including National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service (NMFS), United States Fish and Wildlife Service (USFWS), United States Department of Defense (DOD),  and United States Coast Guard (USCG). 

BOEM uses task forces to facilitate coordination between federal agencies and state, tribal, and local governments during the offshore wind development process. In 2019, BOEM established the Gulf of Maine Intergovernmental Task Force following a request made by Governor Sununu. The Gulf of Maine Intergovernmental Task Force is a regional task force with representation from New Hampshire, Massachusetts, Maine, and federally recognized Tribes. Task Force members are collaborating with BOEM and other federal agencies on renewable energy planning activities in the federal waters in Gulf of Maine. The Gulf of Maine Intergovernmental Task Force held its first meeting in December 2019.

Want to learn more about offshore wind?