A tree as a wind turbine

The Wind Tree in the French Parc du Radôme

The Wind Tree is an unusual construction: a wind turbine in form of a tree with leaf modules that turn in the wind and supply energy. The concept stems from a French company; the frame is provided by Tecpoles. In early 2014 the energy-supplying Wind Tree is ‘planted’ in Brittany.

An idea takes shape

In the year 2013 Jérôme Michaud-Larivière has an idea. The founder of the French energy start-up NewWind not only wants to bank on renewable energies, but to package them in an aesthetic form and also offer them in a small-scale version available to everyone. He develops the Wind Tree: a construction in the form of a tree equipped with micro-turbines that turn in the wind and produce electricity. He has the necessary know-how in the energy sector, but he needs a company that will supply the frame. He travels to the French branch of Tecpoles in Lille with a miniature sample of the Wind Tree in his suitcase. ‘Can you make this in large?’ is his question.

Dynamic challenge

Despite nearly 40,000 special designs a year, this is still an unusual request for Tecpoles. The challenge is not the material, the form of the tree framework or the production of individual parts, but rather the dynamics: poles are usually static elements, but the Wind Tree is a structure that is intended to and has to move constantly. Completely different conditions prevail and various questions arise: Can the model be reproduced in the required size? Is the Wind Tree structurally feasible? And especially: Can our construction continuously withstand the Breton wind?

Developing a stable support structure

A team of young, innovative fresh graduates along with experienced technicians design and calculate – and then decide to try it. ‘It tied up quite a bit of capacity,’ recalls Stephanie Eberhardt from Foreign Sales for the Lighting business unit. The task reads: create a support structure about eight metres high with a diameter of five metres which looks like a tree and can hold about 70 energy-supplying turbines.

Precision is called for

In September 2013 the conceptual planning for the project begins. Before the frame can be produced, an elaborate 3D model must be realised. It will be tested by the client with the laser measuring device – because in the setup all rotors must be positioned exactly vertically in order to catch the wind optimally.

‘Pinpointed welding required a great deal of care,’ says Stefan Gönczi, the technician in charge from Tecpoles. In addition the Wind Tree did not involve a frame made out of a single piece. Around 60 individual parts, from the tree trunk to three main branches and a total of seven levels of branching small parts, had to be precisely adapted and coordinated with each other. ‘It was like an oversized puzzle made from steel,’ recalls Gönczi. Every single tube was labelled with a welded letter on the inside on each end before being coated white. ‘After coating at above 450 °C any other lettering would have disappeared,’ explains the head of the technical team.

A tree grows in two days

A further challenge is the transport of the large quantity of specially-bent single parts to France. In March 2014 Stefan Gönczi and another technician from Tecpoles accompany the cargo to the French community of Pleumeur Bodou. With the help of the French colleagues, the tree is erected in the Parc du Radôme theme park.

First the tree trunk frame is wired and the ‘leaves’ – the green electricity-producing micro-turbines – are mounted on the steel branches and twigs. With the help of an aerial work platform, the single parts are then mounted on the appropriate branches by means of flange connections. After two days the tree is ready to start producing energy.

Technical details


Project duration

Autumn 2013 to spring 2014


Items included in delivery

one frame in the form of a tree


Details

  • Height: 8 m
  • Diameter: 5.5 m
  • Weight: 1300 kg
  • Tree trunk framework: 3 trunks arranged conically 120° apart; cylindrical branches and twigs, coated white
  • Trunk diameter: 200 mm (at base) / 100 mm (at crown)
  • Wall thickness: 6 mm
  • Equipment: 72 wind electricity generators
  • Weight of each micro-turbine: 15 kg
  • Power output in wind conditions: 3 kW

Further information

Project participants

New World Wind

Parc du Radôme

Lighting poles