More than 4,000 gigawatts of estimated gross offshore wind potential lies off the U.S. coastline – that’s more than four times the current generation capacity of the United States. With the coastal and Great Lakes states consuming nearly 80% of our nation’s electricity, offshore wind can play a major role in supplying energy to regions where electricity demand is at a premium. Offshore wind in the United States is just starting to take firm hold on the east coast with the installation of the Block Island Wind Farm in Rhode Island, but the Department of Energy’s (DOE) advanced offshore wind demonstration projects are not far behind. Fishermen’s Energy, in partnership with DOE, is looking to install turbines three miles off of Atlantic City, NJ, in water that’s about 35 feet deep. These turbines, with a rotor diameter bigger than a football field, will be installed on “twisted jacket” foundations developed by Keystone Engineering – a base set up where the legs are angled around a central column, making it easier to manufacture and install.
Offshore wind offers a large, untapped energy resource for the United States, one that can create thousands of manufacturing, construction and supply chain jobs across the country and drive billions of dollars in local economic investments. However, one challenge with offshore wind is that technicians can’t just hop in a truck to go perform maintenance. Whether it’s changing oil in a hydraulic system, performing regular visual inspections, or doing significant repairs on the turbine, technicians have to be able to access the turbine. After the boat ride out, an offshore worker has to account for the wind and the swell of the waves to make a perfectly-timed step off the boat onto the access ladder. Access ladders are connected to one of the sides of the foundation; in other countries, workers have to reach across a gap to grab onto the ladder hand rails, and step across that gap while the boat is still moving. U.S. regulations call for a narrower gap between the boat and the ladder, but stepping across a narrower gap can be more dangerous for the workers because of the unpredictable motion of the boat. So, with Energy Department provided funding, Fishermen’s Energy and Keystone Engineering, who went back to the drawing board and came up with an innovative and safer solution.
“Unlike traditional ladder access where the worker steps from the vessel forward across a gap to the ladder, our innovative ladder is rotated 90 degrees so that the vessel deck can be placed as close as possible to the ladder rail and allow the offshore worker to safely side step onto the ladder,” says Stan White, Program Director of Fishermen’s Energy. “If the offshore worker were to accidentally fall, the worker won’t be pinned between the vessel and the ladder but, instead, the worker would fall in a clear space protected by the fender system.”
A picture of this new ladder may be worth a thousand words, but Fishermen’s and Keystone wanted to demonstrate the safety improvements of this new ladder. So with the support of the Energy Department, they contracted Gulf Island Fabricators in Houma, Louisiana – the same fabrication yard that built the Block Island Wind Farm foundations – to build a full-scale mock-up of the new ladder for offshore technicians, engineers, and regulators to climb on and test out. They also built a full-scale mock-up of the conventional access ladder as a comparison. On August 13, representatives from the Bureau of Ocean Energy Management, Occupational Safety and Health Administration (OSHA), U.S. Coast Guard, American Bureau of Shipping, Siemens, and GE were invited to test out the new system first hand. Everyone was encouraged to step aboard the “boat” and compare the two different access ladders.
“The innovative side step access ladder for transferring workers between a vessel at sea to a fixed structure in U.S. waters satisfies current OSHA regulations while providing a safe worker space, as defined by OSHA, between the surrounding fender structural members and the vessel bumper,” says Rudolph Hall, P.E., Managing Principal of Keystone Engineering, showing that this innovation balances U.S. specific requirements and making sure that workers are safe at sea.
By demonstrating this U.S. innovation as part of the Energy Department’s advanced offshore wind demonstration projects, this access ladder could be adapted to projects around the world, improving the safety of offshore workers globally.
Through targeted investment in research, development, deployment, and market barrier removal, the Energy Department is working to promote the responsible development of a world-class offshore wind industry in the United States.
“Alstom is partnering with several DOE offshore wind projects,” says Andy Geissbuehler, General Manager of GE's Alstom Wind North America.
“These projects, as well as other DOE offshore wind efforts, are vital and highlight the significant potential of offshore wind in the United States. Deepwater Wind’s Block Island Wind Farm, the first commercial wind farm in the U.S., will feature GE’s Haliade 150 6-megawatt turbines. This historic project, as well as the Dominion demonstration project off Virginia Beach, exemplify the investment and innovation that are essential as we develop new technologies to power America’s clean energy future.”
The Wind Program has funded advanced technology demonstration projects with the aim of deploying demonstration-scale offshore wind projects in U.S. waters. These projects will establish key pathways and critical steps for future offshore wind developers, thereby reducing the costs of planning, constructing, and operating offshore wind plants in the United States. Watch this Energy 101 video to learn more about how wind turbines capture wind energy on land and offshore.
Photos courtesy Petersen Studios, Houma, LA