These wooden wind turbines can be completely recycled

Rotor blades made of wood are being tested in Germany for the first time. They are said to be more sustainable than conventional ones made of glass or carbon fibre.

Voodin Blade Technology is a German company based near Kassel. The start-up has taken on something unusual: It manufactures rotor blades from wood. These are now being tested for the first time on an existing wind turbine under real conditions.

A major problem with wind power to date is that conventional rotor blades made of glass or carbon fibre are difficult to recycle. If they are made of wood instead, this could have a favourable effect on the sustainability balance.

Pilot test with existing wind turbine
Voodin is now testing its first prototype. Almost 20 metre-long wooden rotor blades have been attached to an existing wind turbine, as the Ingenieur portal reports. The start-up is also currently developing 2 further, larger rotor blades. These include one that is 60 metres long and a second that is 80 metres long.

For its rotor blades, Voodin uses laminated veneer lumber, which consists of many glued layers of solid wood. In the construction industry, it is often used for highly stressed components such as beams or rafters. For this reason, it is also well suited for the rotor blades.


Rotor blades are currently barely recyclable
According to the US National Renewable Energy Laboratory, up to 90 per cent of a wind turbine can in principle be recycled. However, rotor blades are an exception because they are made of glass and carbon fibres bonded with an epoxy resin. This combination makes recycling difficult and costly. Often these parts simply end up in landfill sites. Voodin claims that its wooden rotor blades are 100 per cent recyclable.

According to Voodin, the wooden rotors would also last longer than those made of fibreglass, as laboratory tests have shown. They should wear less and withstand various weather conditions that prevail in onshore wind farms.

Production with CNC milling
The wooden parts are produced in workshops using CNC milling machines - this is how complex 3D moulds are created. These machines can be used to produce any shape. Production with CNC milling machines should be efficient and cheap. Local production also reduces transport costs and emissions.

Last year, it was announced that the German energy giant RWE had entered into a co-operation with the Swedish company Modvion, which intends to use wooden towers for wind turbines. RWE argued that wood is even stronger than steel if you look at it in proportion to its weight.



Source: futurezone.at