German engineering firm TimberTower seeks to revolutionize the design of conventional wind power plants, making its turbine towers from wood. The construction reaches new dimensions in height and cost-efficiency.
This revolutionary wind-turbine mast construction is still incomplete. The structure, which will one day support a conventional wind turbine, so far stands 60 meters (196 feet) tall - just over half its eventual height.
And the gray plastic skin covering the half-finished construction also doesn't make one think that something revolutionary is going on.
However, a closer look inside the tower quickly betrays what makes it so unusual. Behind the plastic skin, the mast has a timber frame covered in wooden cladding.
The skin is only necessary to protect the timber from bad weather, Holger Giebel, the Chief Executive of German start-up company TimberTower told DW.
Eventually, the wooden tower the engineers are currently erecting will be 100 meters tall and will carry a conventional 1.5 megawatt wind turbine.
TimberTower plans to sell its masts to big equipment manufacturers specialized in the construction of entire wind power plants.
Giebel says wind towers made of wood have various advantages over those made of steel.
"Onshore steel masts can only reach a maximum height of about 110 meters," he told DW. That's because the base of a 110 meter mast has to be 4.2 meters in diameter, and that's the maximum size that can pass under road bridges in Germany and elsewhere.
That doesn't apply to a mast made of wood, which is assembled on the construction site, thus saving in addition enormous transportation costs.
Giebel said that a new tower with a height of 140 meters was currently being planned by the firm for a project near Hanover. The extra height should allow the turbine to generate between 30 and 40 percent more electricity than on a conventional mast, while construction cost would be 20 percent lower.
TimberTower hopes to reduce the cost of wind power generation to just 5 euro cents per kilowatt, which would make it almost as cheap as electricity generated from nuclear power plants.
Homemade building material
Edwin Kohl, who owns a pharmaceutical import firm situated near Saarbrücken, is the company's main investor. He's sunk a double-digit million euro sum into TimberTower and holds 80 percent of the shares.
He's convinced by the sums, but he told DW that it was the environmental aspect of the product that made him share in the endeavor.
"Local access to wood as the building material was important for me because it shows that the energy produced here is really green energy," he said.
Kohl noted that conventional steel towers were made in an unsustainable way as the steel was produced in India with coal mined in Australia before it was built into wind towers in Europe.
"Such a supply chain doesn't really make environmental sense," he added.
TimberTower, which is based in Hanover, doesn't want to disclose revenue figures as yet. But they have set their sights firmly on the world market, in which more than 30,000 wind turbines go online every year.
And in the not too distant future, at least a thousand of them should be resting on towers made of wood.