A Powerplant made from Hemp
In order to be free from dependency on fossil fuels such as coal, gas or crude oil, the energy industries have high hopes on wind power because it is sustainable and available in plenty. However, there is one hitch: Although the wind power plant generates renewable, green energy the plant is made from eco-unfriendly materials. The rotor blades of wind turbines are generally made from glass fiber reinforced plastics. After 20 to 25 years of service, the plant reaches its end of life cycle and in this context the disposal of the fiber- reinforced plastics is problematic.
One possible solution to this problem might be the substitution of eco-unfriendly materials by materials from renewable resources. Currently in the project "Green2Green” funded by the Ministry of Technology (BMVIT) industrial hemp plants will be utilized as sole “green” resource of raw material to develop the structural components of a small wind turbines which in turn generates “green” energy. The partners involved in this consortium project are Kompetenzzentrum Holz GmbH, C6 GmbH, Differences Kunststoffproduktions GmbH, R&D Consulting GmbH & Co KG, Waldland Naturstoffe GmbH and Department of Polymer Engineering at Montanuniversität Leoben.
Hemp has several useful properties: The plant is robust and can be harvested annually. Both the fibers and the extracted oil from the seed of the plant are suitable for technical purposes. Unlike rapeseed or sunflower oil further use of hemp seed oil is not competing with the food production.
The hemp for the “Green2Green” wind power project is grown in Friedersbach, Lower Austria. The plant doesn’t need to be fertilized and can be grown in places even where traditional agriculture is not possible, for example, on brownfields and in water protection zones. For the Green2Green project, two hectares of hemp plant are cultivated annually of which 1600 kg of hemp seeds and 3 tons of straw are harvested in autumn.
From the hemp seeds, the oil is extracted and the oil is converted into a bio-based epoxy resin. The harvested hemp straw has been used as natural fiber reinforcement. The hemp fibers from the straw are spun into yarns which are further processed into technical textiles that can withstand high mechanical loads. Team leader Günter Wuzella: “We want to offer a green alternative to conventional materials. Wind power plants which produce green energy should also be consequently made from green materials”. At present, the developed hemp-based material is optimized. In the upcoming year a small wind power plant will be equipped with rotor-blades made from the hemp-based material.