Life-cycle analysis of product integrated polymer solar cells Nieves Espinosa, * a Rafael Garc  ıa-Valverde a and Frederik C. Krebs b Received 4th February 2011, Accepted 8th February 2011 DOI: 10.1039/c1ee01127h A life cycle analysis (LCA) on a product integrated polymer solar module is carried out in this study. These assessments are well-known to be useful in developmental stages of a product in order to identify the bottlenecks for the up-scaling in its production phase for several aspects spanning from economics through design to functionality. An LCA study was performed to quantify the energy use and greenhouse gas (GHG) emissions from electricity use in the manufacture of a light-weight lamp based on a plastic foil, a lithium-polymer battery, a polymer solar cell, printed circuitry, blocking diode, switch and a white light emitting semiconductor diode. The polymer solar cell employed in this prototype presents a power conversion efficiency in the range of 2 to 3% yielding energy payback times (EPBT) in the range of 1.3–2 years. Based on this it is worthwhile to undertake a life-cycle study on the complete product integrated polymer solar cell. We have compared this portable lighting system with other lighting solutions, namely: a kerosene lamp in a remote rural area in Africa (Ethiopia), as a replacement of a silicon PV based lamp, in place of a torch with non-rechargeable lead-acid battery and instead of a battery charging station. The analysis reveals that the OPV lamp has a significant advantage provided that some of the challenges facing this novel technology are efficiently met such that it can enter the market of portable lighting devices. 1. Introduction Polymer solar cells are a technology that has been touted as the only inherently low cost photovoltaic technology 1–4 for which there are no known limitations in the abundance of the elements in the materials. Of the inorganic photovoltaic technologies only silicon (crystalline, microcrystalline and amorphous) has no identified material shortage problems while many of the poten- tially low cost inorganic photovoltaics are not scalable to multi- GW production volumes due to the low natural abundance for some of the elements that enter as active components in those solar cells (e.g. CdTe, CIGS). 5,6 Polymer solar cells have been shown recently to yield energy pay-back times of 1–2 years and very low CO 2 equivalent emission figures of less than 40 g per kW h el . 7–9 The polymer solar cell technology was thus found to be very similar to other PV technologies in its current form and has the potential to outperform all other known PV technologies through process and technology development. Recently a new record beyond 8% in efficiency was reached. 10 The vision of polymer solar cells is their a Departamento de Electr  onica, Tecnolog ıa de Computadoras y Proyectos, Universidad Polit ecnica de Cartagena, Campus Muralla del Mar. C/Doctor Fleming s/n, 30202 Cartagena, Spain. E-mail: nieves. espinosa@upct.es b Risø National Laboratory for Sustainable Energy, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde, Denmark Broader context Polymer solar cells have been researched broadly in the past decade and are progressing towards large scale manufacture, commercialization and product integration. Most reports present somewhat unrealistic views on the capacity of the technology which must be viewed as marginal compared to existing solar cell technologies. In contrast to most other solar cell technologies polymer solar cells ideally do not present an abundance problem and it is currently the only solar cell technology with manufacturing schemes fast enough to reach production levels of a gigawatt-a-day. Recent efforts have analyzed the impact that polymer solar cell production has on the environment through life cycle analysis. Of the few reports available only one report was based on real production data showing energy payback times similar to the 2 year service life. In this work we address the impact on the energy payback time when this inferior but highly adaptable technology is integrated into products in the form of lighting solutions for developing countries and find energy payback times on the order of 10 years which is significantly longer than the service life. When exchanging existing lighting solutions with the polymer solar cell based lighting solutions energy payback times on the order of 1–2 months are obtained. This journal is ª The Royal Society of Chemistry 2011 Energy Environ. Sci., 2011, 4, 1547–1557 | 1547 Dynamic Article Links C < Energy & Environmental Science Cite this: Energy Environ. Sci., 2011, 4, 1547 www.rsc.org/ees ANALYSIS Downloaded by DTU Library on 27 June 2011 Published on 21 March 2011 on http://pubs.rsc.org | doi:10.1039/C1EE01127H View Online