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Cheap Offshore Wind Turbines on the Horizon

Researchers from the University of Wollongong are developing technologies for offshore wind turbines that are one-third the price, 1000 times more efficient and could be installed off the coast of Australia in the next 5 years.

Materials scientist Dr Shahriar Hossain said current conventional offshore wind turbines cost $15 million each to build, are extremely heavy and difficult to ship out to their location, and require a lot of maintenance thanks to a complicated gear box. “In our design there is no gear box, which right away reduces the size and weight by 40%,” Hossain said.

“We are developing a magnesium diboride superconducting coil to replace the gear box. This will capture the wind energy and convert it into electricity without any power loss, and will reduce manufacturing and maintenance costs by two-thirds.”

Superconductors are a new class of materials that carry electricity with no loss of energy because they have no electrical resistance.

When an electric current is sent into a conduction loop made of conventional copper wire, about 7–10% of this energy is lost due to resistance. The wire heats up and decays quickly. However, if a superconducting material is used, the current will circulate indefinitely even after the power is turned off.

Hossain is developing a magnesium diboride superconducting coil made from magnesium and boron, which is very cheap and easy to manufacture.

Up to 200 km of coil is needed to generate electricity in wind turbines, which would cost $3–5million to manufacture using current technologies. However, the same length of magnesium diboride superconducting coil costs $180,000, and this could reduce dramatically as magnesium diboride becomes less expensive.

In the UK more than $2.5 billion has been invested in offshore wind farms that provide around 8 TWh of electricity annually – the equivalent to the electricity consumption of around two million homes.

Hossain says that Australia needs to start investing in renewable energy sources like wind if it is to achieve its target of an 80% reduction in greenhouse gas emissions by 2050.

“Wind is cheap, clean, and we can get it on rainy and sunny days. And considering Australia has more than 35,000 km of coastline, there is ample room for offshore wind farms. With industry support, we could install superconducting offshore wind turbines off the coast of Australia in 5 years, no problem.”