Life Cycle Assessments
The use of life cycle assessments is a preferred method for comparing the environmental impact of one solution vs. another. The following LCAs or environmental reviews provide insight to the impact of composite material use vs. alternative materials and when compared against other composites.
NREL maintains a large database of LCI information on their website, which can be accessed at:
The ACMA also provides an LCI tool to its members, which can be found here:
Life-Cycle Assessment of Carbon Fiber Reinforced Polymer Composites in Commercial Aircraft
See http://link.springer.com/article/10.1007%2Fs11367-014-0824-0 for an abstract of this 2014 British study by the Universities of Sheffield, Cambridge, and University College London, which compares the environmental performance of composite aircraft such as the Boeing 787 or Airbus 350 to traditional aluminum airliners.
The authors concluded the following:
- Due to the lower lifetime fuel consumption of the light composite plane, its overall environmental impact using a single life cycle assessment score is lower (note: lower score = better). Most of the impact reduction is due to lower CO2 emissions.
- By 2050, estimated CO2 emissions from a global fleet of composite planes would be 14-15% lower than from a fleet of aluminum-based aircraft.
Monterey Bay Aquarium Tank LCA: FRP vs Concrete
See this link for this LCA study, conducted in 2008 as a student research project by Evrydiki Feeka, Forest Flagler, Nick Frieden, Tom Mercer, and Sarah Russell-Smith, under the guidance of Michael D. Lepech, PhD, Assistant Professor, Department of Civil & Environmental Engineering at Stanford University. The subject is a large holding tank to be installed at the Monterey Bay Aquarium Research Institute (MBARI). The LCA compares a tank designed by Kreysler and Associates with FRP walls on a base of reinforced concrete with a tank constructed entirely of reinforced concrete. The study covered impacts from raw material production through disposal at end of the 20 year service life, and included life cycle cost data not normally considered during environmental LCAs. The authors concluded the following:
- The FRP tank had a $300,000 lower cost of ownership across the service life of the tank.
- The FRP tank was more sustainable, outperforming the concrete tank in terms of the most critical environmental attributes: embedded energy, greenhouse gas emissions, solid waste, and acidification.
- For both materials of construction, primary impacts were in the raw material production phase, resin for FRP and cement for concrete.
Life-Cycle Evaluation of Aluminum and Composite Intensive Vehicles
See this link for this 1999 study by the University of Tennessee Center for Clean Products and Technologies comparing a 1994 Chrysler Intrepid sedan against two concept New Generation Vehicles (NGVs) employing advanced materials and drivetrains. Both NGVs were diesel-electric hybrids, one relying heavily on aluminum and the other on thermoplastic composites for weight reduction. Due to the design of the study, it is difficult to draw conclusions on the relative importance of material vs drivetrain. However, the authors conclude that for composite body panels, molded-in color and recycling would both significantly improve environmental performance.
Comparative LCA of Composite Wind Turbine Blades
See this link for this 1997 Dutch study by O.M. DeVagt and W.G. Haije, which compared functionally equivalent wind turbine blades made of glass-fiber reinforced polyester (GFRP), flax-fiber reinforced epoxy (FFRE), and carbon-fiber reinforced epoxy (CFRE). For each, an Eco-Indicator 95 score was calculated to aggregate life cycle impacts across all impact categories. Among study conclusions were the following:
- Per turbine blade, the best (lowest Eco-Indicator score) was FFRE (1.85) vs CCRE (2.40) and GFRP (2.47). These differences are considered “slight.”
- However, per cubic meter of composite alone, the best was GFRP (3.4) vs FFRE (6.6) and CCRE (11.8).
- The marked difference in relative performance of GFRP between these two function unit scenarios is attributed to the greater amount of steel needed to attach the blades to the hub.
Comparative LCA of Sheet Molding Compound Reinforced by Natural Fiber vs. Glass Fiber
See this link for this 2012 study by Jinwu Wang (Washington State University), Sheldon Shi, and Kaiwen Liang (both University of North Texas). The functional unit compared was the mass of sheet molding compound (SMC) that would achieve equal stiffness and stability for production of interior automobile parts. Three composites were considered: traditional glass-fiber reinforced polyester (GFRP), kenaf-fiber reinforced polyester (KFRP), and kenaf-fiber reinforced 20% soy resin (KFSP). Study conclusions:
- Environmental performance was best (lowest impact) for KFRP, followed by KFSP and GFRP.
- Differences between the two kenaf SMCs were slight. Environmental performance of SMC was largely improved by substitution of renewable kenaf for glass as reinforcement.
Comparison of the Environmental Impacts from Utility Poles of Different Materials
See this link for this 2011 LCA study, conducted by Martin Erlandsson of the Swedish Environmental Research Institute, comparing (over the lifetime of 50 years) utility poles made of FRP with a polyethylene shell to those made of 50% recycled steel with a concrete base, creosoted wood, and steel-reinforced concrete.
The authors concluded the following:
- Wood poles are "most competitive" based on all environmental aspects considered, followed by FRP and concrete poles.
- FRP poles had the lowest contribution to human toxicity and ecotoxicity; steel poles the highest
Life-Cycle Assessment of Polymers in an Automotive Assist Step
See this link for this 2012 study by PE International for the American Chemistry Council, which compares (over a service life of 150,000 miles) a standard steel/plastic running board-assist step to a one-piece glass fiber reinforced polypropylene composite alternative, which is 51% lighter.
The authors concluded that the composite assist step outperformed (was better than) the standard version for global warming potential and primary energy demand, but was worse for acidification.