Last week we reported on Scotland giving the nod to the Scotland’s first – and the world’s largest – floating wind farm based on Statoil’s unique Hywind floating wind turbine technology.
That project will enable wind turbines to be positioned 25km from the coast in depths of over 100-metres, generally considered beyond the reach of conventional offshore turbines.
Now researchers from the Department of Civil and Environmental Engineering of the Universitat Politècnica de Catalunya (UPC) in Spain have designed and patented a durable floating platform for offshore turbines modelled on deep sea oil rigs which could go far deeper, and lower the cost of offshore wind power by 12 euro cents per kilowatt hour (kWh).
Called WindCrete, the prototype is a long pole-like structure with a heavy ballast base and floating top to ensure it remains stable in rough seas and high winds. Researchers Climent Molins and Alexis Campos from Barcelona’s School of Civil Engineering said the important innovations of their design were making the cylindrical float one seamless monolithic structure, along with using concrete for construction instead of costly steel.
“By using concrete instead of the more expensive steel that has been used previously, the construction cost is reduced by 60%. In addition, concrete is more resistant in the marine environment, so the structure has fewer maintenance requirements and a life of about 50 years,” a UPC release states.
The WindCrete platform is designed to carry a 5MW wind turbine, but the concept is compatible with turbine capacities of up to 15 MW with a minimum increase in the cost; making it far more economical the researchers say.
The floating system requires minimum depths of around 90-metres, deeper than the vast majority of current offshore wind sites, but has almost no technical maximum depth. Oil platforms in the Gulf of Mexico are currently anchored at depths of up to 2,300-metres.
“The new system reduces the cost of wind energy to 12 cents per kilowatt hour (kWh). This is half the price per kWh of this type of energy (about 24 cents) in the Canary Islands, one of the regions where wind power is to be promoted,” according to UPC.
The WindCrete prototype was included among 18 other designs in the same UK Carbon Trust report that nominated floating wind turbine technologies like Hywind Scotland as lowering wind generating costs by £85-£95 (AUD $182- AUD $ 204) per MWh.
