Number

289-EN

Section

General Section

Use

Abstract

A project showed promising results concerning the substitution of glass fibre/epoxy composite with bamboo/biobased glue composite.

Substituted substances

Alternative Substances

Hazard Assessment

Substances to be substituted: Epoxy, polyester and glass fibres have no harmonised classification according to CLP regulation ( Annex VI of regulation (EC) No 1272/2008), but are related to long term occupational and environmental health hazards. SUBSPORTplus has no information on specific Cas numbers used. Alternative substance: Bamboo fibres are natural plant fibres that do not pose a hazard.

Description of Substitution

The Department of Composites and Materials Mechanics (KOM), DTU Wind Energy at the Risoe Campus is part of the Technical University in Denmark. In the KOM group for several years researchers have worked with the possibilities of using natural fibres like flax and hemp as substitutes for glass fibres in the materials used in the production of blades for wind turbines. Today blades are made of a composite based on around 60% glass fibre and 40% epoxy or polyester resin. In a joint venture between the KOM group and the International Centre for Bamboo and Rattan in China, the possibility of substituting the glass fibre laminates with a bamboo based composite with an epoxy resin was studied. In the Chinese project it has been demonstrated that blades up to 30-40 meters long can possibly be produced from a composite consisting of 90% bamboo and 10% epoxy, hereby reducing the amount of epoxy used in blades considerably. Research and technical tests also showed that for small blades (up to 15 meters long), it should be possible to produce wings based on bamboo or other natural fibres and a biobased resin without epoxy. The technology used in the production process is the same as for glass fibre blades. A life cycle assessment has been performed by a group of students at Roskilde University Centre in Denmark. The report concludes, that "bamboo material fulfilled the requirement of constructing a turbine blade and has a high performance associated with sustainable development". The test results were very promising, but a production depends on a reliable source of bamboo delivery, and this is where the project stopped. It was not possible to reach an agreement concerning deliveries from the Chinese bamboo forests. DTU Wind Energy has tried to get bamboo from other countries – e.g. Ecuador – but has not succeeded yet. Another limiting factor is that until now the biobased resins has been more expensive than the epoxy resin, and cost reduction is a crucial business driver for the wind turbine manufacturers. The results obtained up to now are promising, and should be the onset of initiatives in innovative companies to start producing prototypes of the blades based on natural composite materials. As far as DTU Wind Energy is informed this has not been initiated yet.

Case/substitution evaluation

Epoxy, polyester and glass fibres used in the traditional blades are related to long term occupational and environmental health risks. Substitution with bamboo fibres and a biobased resin can reduce these risks.

State of implementation

Pilot study

Date and place of implementation

2011

Availability ofAlternative

Bamboo fibers are available, but for to start a production a reliable source of delivery need to be established

Type of information supplier

Research

Contact

Danish Technological University https://www.dtu.dk/EN

Further information

Yinyao Qin, Jie Xu, Yu Zhang: Bamboo as a potential material used for Windmill Turbine Blades - a Life Cycle Analysis with sustainable perspective. Roskilde University Centre, December 2009.

Date, reviewed

November 26, 2021