Engineers have managed to increase the rotor diameter of wind turbines a staggering 40 per cent by trimming and augmenting their blades using traditional surgical techniques.

Increasing the size of wind power turbines has been a key imperative for renewable energy engineers over recent decades, given that larger rotors are capable of harnessing the wind’s energy far much heightened efficiency.

Increasing the size of rotors enables turbines to better harvest the power of the wind, yet does not translate into corresponding gains of a proportional nature in the mass of the rotors themselves or their supporting towers.

According to a recent survey by Environmental Science & Technology, the dimensions of the average commercial wind turbine have increased tenfold over the past three decades, from around 15 metres in 1980 to over 150 metres today.

Engineers from GE’s wind unit have now developed a method for increasing turbine sizes which is akin to a surgical procedure, and involves the dismemberment of existing blades to augment their length via the insertion of custom-manufactured extensions.

Mark Johnson, engineering leader at GE Renewable Energy, led a team of researchers in successfully performing augmentation surgery on a standard 37-metre long wind blade.

The blade is first secured into a fixture before being cut down the centre and divided into two separate halves. A seven-metre extension piece with suction side inserts is then placed in between the dismembered sections, and attached to both of them via the addition of pressure side inserts, in a process which bears an uncanny resemblance to surgical limb repair.

According to GE engineers, the new method is capable of increasing rotor diameter by 40 per cent and can boost the power production of wind turbines by over 20 per cent by allowing them to harvest energy from winds moving at slower speeds.

The research project has already obtained a slew of 16 patent applications, while the augmented blades have managed to pass the barrage of stringent tests set by the International Electrotechnical Commission. These include static strength tests, and fatigue tests involving over 6 million cycles.