A comparative human health, ecotoxicity, and product environmental assessment on the production of organic and silicon solar cells

Abstract

A life cycle assessment case study involving organic photovoltaic technology using phenyl-C₆₁-butyric acid methyl ester and poly(3-hexylthiophene) is presented. Although solar technology converts freely available solar radiation into more useful forms of energy, potential environmental impacts can occur during the life cycle of the product. A cradle-to-gate life cycle assessment is completed, comparing organic solar cells with traditional silicon-based cells across 18 multiple criteria. The functional unit is defined as the production of 1 watt-peak of electricity produced. The inventory is based on prospective organic solar cell technology and two traditional silicon technologies. The results demonstrate that from a life cycle perspective, organic solar cells can outperform conventional silicon solar cells with impacts reduced by 93%. The energy payback time for the default organic photovoltaic cell was 0.21 years (75 days) compared with multicrystalline silicon and amorphous silicon's 2.7 and 2.2 years, respectively. The minimum required lifetime of the organic cells, so that their impacts were no worse than amorphous silicon's over 25 years, was measured between 1.2 and 8.9 years. Results of the sensitivity analysis demonstrate that consideration of manufacturing routes (e.g., fullerene or solar cell production) can be targeted using life cycle assessment for further improvements in the environmental, human health, and ecotoxicity profile of organic solar cells. Copyright © 2015 John Wiley & Sons, Ltd.