Vestas unveils large diameter tower

Danish turbine maker Vestas is about to launch a new large diameter tower designed to lift 3MW machines up into the richer wind stream above 140 metres.

The concept, called the Large Diameter Steel Tower (LDST), is calculated to have the potential of boosting annual production from low-wind sites by as much as 8%.

"Vestas’ product development strategy is to continue to optimise our technology in order to lower the cost of energy for our customers,” states chief technology officer Anders Vedel. “The LDST is the most cost efficient solution in the industry to meet the demanded increased tower height for the 3MW turbines.”

On a project site with a mean wind speed of 6.5m/s, the LDST is estimated to push up output by up to 8% at a hub height of 137 metres for the V126-3.3MW, compared to a hub height of 117 metres for the conventional steel tower.

The LDST, which will have base diameter of 6.3 metres where the existing tower is 4.2 metres, will be available in 137 metres for the V126-3.3 MW and 141.5 metres for the V117-3.3MW.

The wider diameter of the tower presents "a challenge in terms of transportation", Vedel admits.

"We have solved this by delivering the bottom tower section in three lengthways segments. These can easily and cost effectively be transported on a flatbed truck and reassembled on site using vertical flanges to ensure strength."

A prototype for the V112-3.3 MW was delivered in Germany in 2013.

Vestas says it has already received "firm orders" for over 50 turbines using the LDST tower.