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Sustainable design for sustainable energy

Sustainable design for sustainable energy

8/10/12

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.