As offshore wind farms become more common — from the world’s largest wind farm, which opened this summer, to the coming Cape Wind project — a new study suggests that manufacturers should consider changing their designs. New methods can make offshore wind farms as much as 100 percent more efficient in terms of “energy payback,” according to the Cambridge University study.

Energy payback considers how much energy goes into producing a device, and compares that with output. When wind turbines are designed for use on land, the blades that capture wind and the mechanisms that produce electricity typically account for most of the energy used to manufacture the turbines. The tower and foundation, which support the turbine, usually uses only a third of the energy in production.

Offshore wind turbines are different: The towers and foundations must be much taller, heavier and larger. The steel and concrete used in these structures takes much more energy in manufacturing. Steel can also corrode, shortening its lifespan.

The researchers suggest that using different materials can help solve these problems. Composite materials, which are currently used to make some wind turbine blades, can also be used for towers. These materials are corrosion-free, lighter, stronger and more resilient than steel, according to the researchers. They’re also less expensive.

Using “guyed” towers, which are held in place with steel cables rather than free-standing, can also help reduce the amount of energy used in manufacturing, and the researchers say it can be an important first step before manufacturers are able to change materials. Eventually, they will be able to save significant cost and energy, doubling energy payback ratios.

Main image credit: C.G.P. Grey/Flickr