Embodied Energy

The energy consumed by the production of FRP materials, also referred to as material-embodied energy, can vary significantly according to the type of the fibres and the manufacturing processes.

While carbon fibre gives greater weight savings, the environmental impact of carbon fibre reinforcement is much higher (approx. 10 times) than that of glass fibre, because manufacture of carbon fibre precursors and the fibres themselves is very energy intensive. Use of carbon fibre from recycled sources can reduce this impact. Recycled carbon fibres are now available as short chopped fibres and as non-woven mats, though use in primary structural applications is limited by lack of alignment. In the future, carbon fibre from plants where renewable energy is used and from bio-based precursors may further reduce impact.

In glass fibre reinforced polymers, the polymer resin has the highest material impact. Use of bio-based or partially bio-based resins may reduce this.

Values quoted for embodied energies vary widely. The list (Song, et al, 2009) in the table below is a useful guide showing a range for common constituent materials for FRP, derived from various sources.

Material Energy Content (MJ/Kg)
Carbon Fibre 183-286
Glass Fibre 13-32
Polyester resin 63-78
Epoxy resin 76-80

Download our technical sheet on Environmental Impact and Embodied Energy

Download the Noorland bridge environmental impact and embodied energy case study