2020-09-16, Schmidt, Felix, Lenz, Markus, Schaeffer, Andreas, Zimmermann, Yannick, Alves dos Reis Benatto, Gisele, Kolvenbach, Boris, Krebs, Frederik

The low environmental impact of electricity generation using solar cells crucially depends on high energy-conversion efficiencies, long lifetimes and a minimal energy and material demand during production. Emerging thin-film photovoltaics such as perovskites on plastic substrates could hold promise to fulfil all these requirements. Under real-world operating conditions photovoltaic operation is challenged by biological stressors, which have not been incorporated for evaluation in any test. Such stressors cause biodeterioration, which impairs diverse, apparently inert materials such as rock, glass and steel and therefore could significantly affect the function and stability of plastic-based solar cells. Given that different photovoltaic technologies commonly use similar materials, the biodeterioration mechanisms reviewed here may possibly affect the efficiency and lifetimes of several technologies, if they occur sufficiently fast (during the expected lifetime of photovoltaics). Once the physical integrity of uppermost module layers is challenged by biofilm growth microbially mediated dissolution and precipitation reactions of photovoltaic functional materials are very likely to occur. The biodeterioration of substrates and seals also represents emission points for the release of potentially harmful photovoltaic constituents to the environment

2016, Sondergaard, Roar R., Zimmermann, Yannick, Lenz, Markus, Krebs, Frederik, Martinez Espinosa, Nieves

Recovery of silver from the electrodes of roll-​to-​roll processed org. solar cells after incineration has been performed quant. by extn. with nitric acid. This procedure is more than 10 times faster than previous reports and the amt. of acid needed for the extn. is reduced by a factor of 100-​150. LCA studies show that the resulting environmental impacts from silver extn. of incinerated ashes are more favorable on almost all std. factors compared to extn. from shredded org. solar cells. The so lessened environmental impacts by efficient recovery fully justify the use of Ag as an electrode in scaled prodn. of org. solar cells.

2016, Martinez Espinosa, Nieves, Zimmermann, Yannick, dos Reis Benatto, Gisele A., Lenz, Markus, Krebs, Frederik

The emission of silver and zinc to the aq. environment (rain, fog, dew) from polymer solar cells installed outdoors is presented. Studies included pristine solar cells and solar cells subjected to mech. damage under natural weather conditions in Denmark. We find the emission of silver and zinc to the environment through pptd. water for damaged solar cells, and also obsd. failure and emission from an initially undamaged device in an expt. that endured for 6 mo. In the case of the damaged cells, we found that the drinking water limits for Ag were only exceeded on a few single days. We also progressed our studies to include end-​of-​life management. To assess the implications of improper practices (uncontrolled disposal, landfilling) at the end-​of-​life, we buried different OPV types in intact and damaged forms in soil columns. In the case of high Ag emission (shredded cells)​, the potential for migration was confirmed, even though the soil was found to exhibit sequestration of silver. We conclude that recycling of Ag at the end-​of-​life is mandatory from an environmental point of view.