Spanish industrial engineering firm M Torres has installed its prototype 1.5 MW variable speed wind turbine after extensive test bed trials at the company's Pamplona factory. Apart from representing the first foray into multipole generator technology by a Spanish manufacturer, the company is also capitalising on its aeronautical experience with a lightweight rotor using carbon fibre. The prototype has glass fibre blades, but the M Torres is aiming to have a second machine up with its own blades by the end of the year, says the company's José Sancho. An automated production process makes the choice of carbon fibre competitive, says Sancho. A carbon fibre central beam, or cone, will run the length of the blade, while the blade shells and surface are to be made of glass fibre. Experiments with carbon fibre shells proved them to be too costly, but the carbon fibre cone offers better tolerance to fatigue and greatly improved rigidity thus allowing weight savings. "A standard 72-metre glass fibre rotor would weigh in at about 5500 kilos while our blades would reduce this to 2500 kilos," he says. Reduced weight is important in Spain where many of the country's best wind sites are in the mountains. M Torres blades will be made in sections that can be transported separately.