New insights into the environmental performanceof perovskite on silicon tandem solar cells a life cycle assessment of industrially manufactured modules

LCA studies of perovskite on silicon tandem PST cells have so far been heavily reliant on laboratory data and process data from test facilities to project environmental impacts, producing results that differ significantly from one another. This paper reports on potential environmental impacts of an industrially manufactured PST module. Based on process data from a volume manufacturing line in Brandenburg, Germany, a comprehensive life cycle assessment LCA was performed using the ReCiPe 2016 v1.1 method. The production of one module was estimated with a global warming potential GWP of 434 kg CO2 eq., terrestrial ecotoxicity potential of 598 kg 1,4 DB eq., freshwater consumption FWC of 14 m3, and fossil and metal depletion potential FDP and MDP of 164 kg oil eq. and 2034 g Cu eq., respectively. In line with other studies, the environmental performance of the PST module was largely influenced by the amount of energy consumed in the course of production, making the silicon wafer production the determining process step in most impact categories considered. Exceptions were found with the metal depletion potential MDP and terrestrial ecotoxicity potential TETP , where copper, aluminum and float glass implemented in the cell manufacturing and module production process decisively determined the impacts of production. The built in lead, on the other hand, had no significant influence on the result of the toxicity specific impact categories in ReCiPe, even if complete lead emission was assumed. The results were also analysed and compared to those of a silicon hetero junction solar cell SHJ module, modelled analogously to the PST production process. While we found the overall environmental impact of the PST module per piece to be higher than that of the SHJ module in most impact categories up to 7 due to the additional process steps, a comparison made on the basis of kW h produced shows advantages for the PST module with 6 18 across all impact categories, as a higher efficiency overcompensates the higher environmental burden of production, assuming the same lifetime for both module

Pig manure treatment with housefly (Musca domestica) rearing – an environmental life cycle assessment

The largest portion of a product’s environmental impacts and costs of manufacturing and use results from decisions taken in the conceptual design phase long before its market entry. To foster sustainable production patterns, applying life cycle assessment in the early product development stage is gaining importance. Following recent scientific studies on using dipteran fly species for waste management, this paper presents an assessment of two insect-based manure treatment systems. Considering the necessity of manure treatment in regions with concentrated animal operations, reducing excess manure volumes with the means of insects presents a potentially convenient method to combine waste reduction and nutrient recovery. An analytical comparison of rearing houseflies on fresh and pre-treated pig manure is reported with reference to agricultural land occupation, water and fossil depletion potential. Based on ex-ante modelled industrial scale rearing systems, the driving factors of performance and environmentally sensitive aspects of the rearing process have been assessed. Expressed per kg manure dry matter reduction, the estimated agricultural land occupation varied between 1.4 and 2.7 m2yr, fossil depletion potential ranged from 1.9 to 3.4 kgoil eq and the obtained water depletion potential was calculated from 36.4 to 65.6 m3. System improvement potential was identified for heating related energy usage and water consumption. The geographical context and the utility of the co-products, i.e. residue substrates and insect products, were determined as influential variables to the application potential of this novel manure treatment concept. The results of this study, applied at the earliest stages of the design of the process, assist evaluation of the feasibility of such a system and provide guidance for future research and development activities.The research leading to these results has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 312084 (PROteINSECT)

Implementing Insect Production in Agricultural Value Chains - An ex-ante life cycle evaluation

An ever-growing demand for animal based food products is affecting the productivity of global food production systems, and urgently needed measures to curb further environmental degradation promise similar effects. Whether future demand scenarios can be met sustainably, depends not least on whether it is possible to significantly reduce the environmental impact of aquaculture and livestock production. Recent research suggests that the use of insect based feeds (IBFs) could make a significant contribution in this regard, and in fact valid arguments are put forward to support this conjecture. Fly larvae, like those of houseflies (Musca domestica) or black soldier flies (Hermetia illucens), are able to source nutrients from a wide range of different organic resources, including those unsuitable for human consumption. This creates the opportunity to convert (and significantly reduce) low-value organic wastes, such as manure or animal blood, into high-quality proteins and dietary energy, proven to be suitable for feeding different aquaculture fish and monogastric livestock. Although the IBF concept promises great benefits and has demonstrated its technical feasibility, there are as of yet no established systems by which conjectured sustainability benefits could be tested. In this thesis we tried to overcome this shortcoming by modelling such systems. Our central objective was to identify the aspects influencing the application potential of IBFs in different geographical contexts and delineate optimization pathways for a sustainable implementation. Drawing on experimental data gathered from rearing trials in Europe (Spain and Slovakia) and West Africa (Ghana and Mali), we formulated the design of a set of up-scaled system versions rearing M. domestica and H. illucens on different low-value organic substrates. The generic production models served as a basis for an ex-ante life cycle analysis, in which we explored the systems' performances using environmental life cycle assessments (LCAs) and life cycle costing (LCC). The LCC and LCA analysis showed that the environmental and economic performance of IBFs are largely a function of the systems' conversion efficiency, the organisation of the production process (i.e., input of labour and technological equipment), and the geographical context. The combination of these factors provided advantages for the simplistic setups used in the production of M. domestica under conditions of natural oviposition (i.e., substrate inoculation through naturally occurring flies) in tropical West Africa. Artificial inoculation (i.e., substrate inoculation through nurtured larvae from a captive adult colony), driving the production of H. illucens in West Africa and M. domestica in Southern Spain, facilitated a high conversion efficiency but raised environmental impacts and costs, as the complex system setup and labour intensive process organisation substantially increased inputs of labour and production infrastructure. A benchmark comparison with conventional protein-rich feeds pointed towards environmental and economic disadvantages of current IBF production designs, especially in reference to plant based feeds (e.g., soybean meal). The disparities between IBF and conventional feeds mirror the systems' sub-standard capacity utilisation (insufficient economy of scale effect), as well as the loss of energy and biomass along the trophic chain (autotroph producers vs. heterotroph consumers). These findings raise legitimate doubts as to whether an implementation of insects in present agricultural value chains offers any sustainability benefits compared to conventional feeds. Commercial success greatly depends on the site-specific wage level, the prices of rearing substrates and how markets rate the multiple functions insects are capable to deliver. As it concerns the environmental performance, our results lead us to conclude that the production of IBFs offers no advantages over conventional feeds. The assessment of yet hypothetical production systems involved a fair amount of assumptions and approximations. Given these multiple sources of uncertainty, and taking into account that only a limited number of possible system designs are considered, statements on the application potential of IBF hold no universal validity and should be interpreted with caution. However, our findings contribute to a better understanding of the factors influencing the application potential of insect production systems and serve as a valuable point of reference for scientific discussions and future research and development activities aiming for sustainable food production patterns. While our research offers no support for conjectured environmental or economic advantages of using insects as feed, it might be that their use as food for direct human consumption (i.e., as a possible substitute for fish and meat products) provides a sustainable solution to current and future food problems. We therefore advise future research to focus on techniques enabling the exploitation of insects as food.status: publishe

Life Cycle Inventory Analysis of Prospective Insect Based Feed Production in West Africa

© 2017 by the authors. While the concept of insect based feeds (IBFs) promises great potential, especially in developing countries, the sustainability performance of IBF production remains widely underexplored. Drawing on experimental data from rearing trials in West Africa, three different insect production systems were modelled ex-ante. The generic models served as a basis to analyse and compare the process performances of different IBF production systems using Musca domestica and Hermetia illucens reared on different substrates. The results show that the input efficiency in the production of IBF is largely determined by the quality of rearing substrates, the larval development time and the employed inoculation practises, i.e., the method by which eggs or larvae are added to rearing substrates. The H. illucens system ranked highest for conversion efficiency (substrate input per IBF output), but showed substantially higher inputs in labour, fossil energy and output of wastewater. M. domestica systems operated at lower conversion efficiencies, which resulted in higher outputs of residue substrates, together with higher emissions, land requirements, built infrastructure and water. By offering full disclosure of generic inventory data, this study provides data and inspiration for prospect research and development activities and offers a reference to future life cycle assessments (LCAs) on IBF.status: publishe