WIND turbines that do not need big cranes sounds like the lifting industry’s worst nightmare, given the amount of business crane rental companies are currently getting from the growth of wind power.
So lucrative is the market proving that Demag introduced a special Sideways Superlift boom attachment at Bauma this year aimed directly at wind turbine erectors.
A US company called Valmont is seeking to put a dent in the crane industry, however, having developed a self-erecting wind turbine which needs no major cranage.
The so-called Valmont Wind Energy Structure, with patents pending, incorporates a self-erecting structure with a mobile turbine lifting platform that operates like a giant elevator, raising the turbine and rotors to the top of the structure.
Valmont, an established manufacturer of utility poles, claims that its system offers cost savings in both construction and shipping, since the structure is modular and composed of sections described as being ‘of manageable size’. It claims that an experienced crew of six can erect a 63m structure in two days using the Valmont Structure Lifting Device.
According to Valmont, the system is cost-effective for structures up to 120m high with turbines up to 2.5MW.
First customer to be signed up is Omaha Public Power District. Installation of a working turbine on a 63m prototype structure is scheduled for later this year. The tower has a 1.6m uniform shaft diameter with 12.7mm to 16.9mm wall thickness.
The system can also be used offshore, again without large cranes, says Valmont.
