Sustainable design for sustainable energy

The United States has set a goal of generating 54 gigawatts of offshore wind energy by 2030 — enough to power tens of millions of American homes. But in order to reach that goal, experts must first overcome a variety of limitations, including the vulnerabilities of wind farms in hurricanes.

Andrew Myers, an assistant professor of civil and environmental engineering at Northeastern University, has been awarded a $325,000 grant from the National Science Foundation to develop a series of structural models that can predict how vulnerable wind farms are to hurricanes. Hurricane frequency, intensity and their effect on the environment will all be factored into the models.

Jerry Hajjar, chair of Northeastern’s Depart­ment of Civil and Envi­ron­mental Engi­neering, and Sanjay Arwade, an associate professor of engineering at the University of Massachusetts at Amherst, will serve as the grant’s co-principal investigators.

The U.S., said Myers, does not currently have any offshore wind farms. This deficiency is in stark contrast to our European neighbors, who have thousands of turbines decorating their coastlines.

But the environment off the coast of Europe is significantly different from that off the Atlantic coast, where hurricanes pose a major concern. “Insurance companies need to know the risk to these structures to give them a better idea for how to price risk appropriately,” said Myers, who has conducted similar research on onshore turbines with respect to earthquake vulnerability.

Myers will focus his research on the variety of support structures that can be used in the offshore setting. These include monopile supports, in which the turbine shaft burrows into the ground below the water; jacketed and tripod supports, which include a truss leg structure around the turbine shaft; and floating turbines, which are tethered to the ground with steel cables.

Each of these designs can borrow from the extensive technical experience of the oil and gas industry, but, Myers said, “both the dynamics of offshore wind turbines and the environment are different, as most of the oil and gas structures are located in the Gulf of Mexico.”

The Atlantic Coast will likely be the site of the nation’s first offshore wind farm, Myers said, because of “shallow water, good wind resources and proximity to population centers.” This, he noted, means that we need to understand the intricacies of the wind farm’s environment before realizing the 54-gigawatt goal.

Myers hopes his research will inform design guidelines specific to the North American environment. “One of the major issues is that the international design standard does not explicitly consider hurricanes,” he said. “They simply say that this situation deserves special consideration.”

“Wind energy is more expensive than it has to be because of the uncertainty in the financial risk,” he added. “I see this as an unnecessary barrier to renewable energy.”

Myers’ study of the vulnerabilities of nontraditional, renewable energy structures aligns with Northeastern’s focus on use-inspired research that solves global challenges in health, security and sustainability.