Wind farms installed at sea reportedly generate 40% more energy than those on land, and with that in mind, Siemens is currently constructing the world’s largest wind turbines blades in order to help Dong Energy generate as much wind power as possible. As part of the project, Siemens will install 300 gearless, new-generation 6 MW wind turbines off Britain’s coast which are expected to supply about 1.8 million households with environmentally friendly electricity by the year 2017.
The new mega-turbines—that will have a total capacity of 1,800 megawatts—are expected to set new standards in efficiency and cost-effectiveness, however it is the massive B75 rotor blades that are the key. Just shy of the wingspan of an Airbus 380, the massive blades have a length of 75 meters, making them the world’s largest. The facts and figures get even more mind-boggling when you take into account the diameter of 154 meters, which means in a single rotation, they sweep across an area of 18,000 square meters—that’s equivalent to 2.5 soccer fields!
For their size, the B75 rotor blades are also incredibly light. Sure, they weight 25 tons, but in comparison to standard turbine blades, they are 10-20% lighter. All of this helps to reduce construction costs for foundations embedded in the seafloor. Siemens have managed to achieve this light weight design by using their patented “IntegralBlade” process, which means the blade features no seams or bonding points. The engineering firm make the blades from a single fibreglass mould making it the largest fibreglass component ever manufactured whilst providing maximum yield, maximum strength, and minimum weight.
The B75 blades will first be installed on the second prototype of the 6 MW Siemens offshore wind turbine being built in the Danish Østerild this summer – once Siemens work out how they are going to transport the massive blades!
Images: Siemens, Martin Pettitt