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Publikation Organic photovoltaics: Potential fate and effects in the environment(Elsevier, 2012) Zimmermann, Yannick-Serge; Schäffer, Andreas; Hugi, Christoph; Fent, Karl; Corvini, Philippe; Lenz, MarkusIn times of dwindling fossil fuels it is particularly crucial to develop novel “green” technologies in order to cover the increasing worldwide demand for energy. Organic photovoltaic solar cells (OPVs) are promising as a renewable energy source due to low energy requirement for production, low resource extraction, and no emission of greenhouse gasses during use. In contrast to silicium-based solar cells, OPVs offer the advantages of light-weight, semi-transparency and mechanical flexibility. As to a possible forthcoming large-scale production, the environmental impact of such OPVs should be assessed and compared to currently best available technologies. For the first time, this review compiles the existing knowledge and identifies gaps regarding the environmental impact of such OPVs in a systematic manner. In this regard, we discuss the components of a typical OPV layer by layer. We discuss the probability of enhanced release of OPV-borne components into the environment during use-phase (e.g. UV- and biodegradation) and end-of-life phase (e.g. incineration and waste disposal). For this purpose, we compiled available data on bioavailability, bioaccumulation, biodegradation, and ecotoxicity. Whereas considerable research has already been carried out concerning the ecotoxicity of certain OPV components (e.g. nanoparticles and fullerenes), others have not been investigated at all so far. In conclusion, there is a general lack of information about fate, behavior as well as potential ecotoxicity of most of the main OPV components and their degradation/transformation products. So far, there is no evidence for a worrying threat coming from OPVs, but since at present, no policy and procedures regarding recycling of OPVs are in action, in particular improper disposal upon end-of-life might result in an adverse effect of OPVs in the environment when applied in large-scale.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Opciones para el aprovechamiento energético de residuos en la gestión de residuos sólidos urbanos. Guía para los responsables de la toma de decisiones en países en vías de desarrollo y emergentes(Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, 2017) Mutz, Dieter; Hengevoss, Dirk; Hugi, Christoph; Gross, Thomas05 - Forschungs- oder ArbeitsberichtPublikation Anaerobic digestion of biowastes in India: Opportunities, challenges and research needs(Elsevier, 15.04.2019) Breitenmoser, Lena; Gross, Thomas; Huesch, Ragini; Rau, Julius; Hugi, Christoph; Wintgens, ThomasThe quest for improved living conditions in rapidly growing Indian communities puts pressure on natural resources and produces emissions which harm the environment, society and the economy. Current municipal solid waste (MSW) practices are an important example, as most waste remains untreated and is often deposited on unsafe dumpsites or burned on open fires. Anaerobic digestion (AD) is an option to treat the large biodegradable fraction ('biowaste'). In rural parts of India, the technology to supply energy from biogas has been promoted for 30 years. Biowaste treatment in urban MSW management and organic fertilizer ('digestate') production for agriculture via AD have more recently gained attention but with limited success so far. Recent environmental policies in waste, energy, agricultural and other sectors have, however, set important cornerstones for a broader diffusion in the coming years. On the basis of peer-reviewed literature and governmental reports, we identify barriers and enabling factors along the AD chain (biowaste to technology to product utilization), and analyse relevant boundary conditions for the new multi-sector policies. We show that AD implementation has repeatedly failed due to unrealistic assumptions on biowaste quantity and quality, underestimation of the complex biowaste supply chain, unsuitable AD designs and overestimation of economic returns from biogas and digestate. Local knowledge and capacities for planning and process control are lacking in many places and resources required for operation and maintenance in the long run have often been ignored. We found that the multi-facetted value propositions of AD - including biowaste treatment, energy and fertilizer products - have only been partially tapped due to the exclusive focus on biogas. The new sector policies provide important enabling factors for change. Decentralized AD plants operating on a few tons biowaste per day from reliable and manageable sources (e.g. fruit and vegetable markets) could be a more promising step forward than large-scale investments which rely on large biowaste volumes from various sources. The parallel development of biowaste management, planning tools for municipalities, standardized digestate monitoring protocols and studies on simple, low-cost optimization measures for methane recovery from a wide range of biowastes and innovative high-solid AD digester designs will be prerequisites for the long-term future of AD projects.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Poseidon—Decision Support Tool for Water Reuse(Elsevier, 2019) Oertlé, Emmanuel; Hugi, Christoph; Wintgens, Thomas01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Umweltnutzen eines Hausmanagers (Custom Energy Manager) im progressiven Energieszenario 2035 der Fachhochschule Nordwestschweiz(2019) Hengevoss, Dirk; Hugi, Christoph; Kunz, Dominique04A - Beitrag SammelbandPublikation Environmental potential analysis of co-processing waste in cement kilns(Kharkiv State Academy of Physical Culture, 2019) Kleshchov, Anton; Hengevoss, Dirk; Hugi, Christoph01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Modular Pico-hydropower System for Remote Himalayan Villages(Springer, 01/2018) Zahnd, Alex; Stambaugh, Mark; Jackson, Derek; Gross, Thomas; Hugi, Christoph; Sturdivant, Rick; Yeh, James; Sharma, Subodh; Sajigh, AliRemote, high-altitude villages in the Nepalese Himalayas belong to the poorest and most underdeveloped communities in Nepal, with many still years/decades away from access to electricity. It is common that first-time electrification of these villages is through a 15–50 kW micro-hydropower (MHP) system, subsidized by the Nepal government. The majority of the so far installed MHP systems in the region are however within 3–12 months after they have been commissioned either inoperable due to premature equipment breakage, inappropriate operation, and absent maintenance or do not provide the expected power output. No mechanism is put in place to build an operating and maintenance fund, further putting the longevity of the system at risk. The “dreams” of villagers, promised by such development projects, remain unfulfilled and most often shattered. This paper describes a modular pico-hydropower (PHP) system (1–5 kW) being pursued in the village of Moharigaun in the Jumla district of Nepal whose capacity can be expanded as the village’s power demand, population, and ability to operate and maintain the system grow. This modular PHP system provides reliability through redundancy and the elimination of some of the more maintenance-prone components. The turbine water and electricity delivery infrastructure are buried to protect them from the elements and potential mischief. Most importantly, a prepayment system with remote disconnect capability ensures households pay into an operations and maintenance fund. The whole village community is actively involved in each step of the project (planning, implementation stages, and training), so they will develop a strong ownership for their PHP system. Further, local people, chosen by the community, will be trained to properly operate, administer, and maintain the PHP system.04A - Beitrag SammelbandPublikation Methane potential from municipal biowaste: Insights from six communities in Maharashtra, India(Elsevier, 04/2018) Breitenmoser, Lena; Dhar, Hiya; Gross, Thomas; Bakre, Milan; Huesch, Ragini; Hugi, Christoph; Wintgens, Thomas; Kumar, Rakesh; Kumar, SunilAnaerobic digestion (AD) of biowaste can generate biogas with methane (CH4) as energy source and contribute to sustainable municipal solid waste management in India. Characteristic municipal biowastes sampled seasonally from household, fruit and vegetable market and agricultural waste collection points in villages, towns and cities in Maharashtra were analysed to assess the potential as substrate for AD. The mean biochemical methane potential (BMP, at 37 °C) across seasons and community sizes was between 200-260, 175-240 and 101-286 NLCH4 kgvs-1 for household, market and agricultural biowaste, respectively. CH4 yields were comparable in villages, towns and cities. Seasonal variations in CH4 yields were observed for market and agricultural biowaste with highest values during pre-monsoon season. Results underpin that municipal biowaste is a suitable substrate for AD in India. However, low purity of available biowaste resulted in lower CH4 yields compared to recent studies using source-segregated biowaste.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Re-using bauxite residues: benefits beyond (critical raw) material recovery(Wiley, 2018) Ujaczki, Eva; Feigl, Victoria; Molnar, Monika; Cusack, Patricia; Curtin, Teresa; Courtney, Ronan; Ronan, Lisa; Davris, Panagiotis; Hugi, Christoph; Evangelou, Michael; Balomenos, Efthymios; Lenz, MarkusSince the world economy has been confronted with an increasing risk of supply shortages of critical raw materials (CRMs), there has been a major interest in identifying alternative secondary sources of CRMs. Bauxite residues from alumina production are available at a multi-million tonnes scale worldwide. So far, attempts have been made to find alternative re-use applications for bauxite residues, for instance in cement / pig iron production. However, bauxite residues also constitute an untapped secondary source of CRMs. Depending on their geological origin and processing protocol, bauxite residues can contain considerable amounts of valuable elements. The obvious primary consideration for CRM recovery from such residues is the economic value of the materials contained. However, there are further benefits from re-use of bauxite residues in general, and from CRM recovery in particular. These go beyond monetary values (e.g. reduced investment / operational costs resulting from savings in disposal). For instance, benefits for the environment and health can be achieved by abatement of tailing storage as well as by reduction of emissions from conventional primary mining. Whereas certain tools (e.g. life-cycle analysis) can be used to quantify the latter, other benefits (in particular sustained social and technological development) are harder to quantify. This review evaluates strategies of bauxite residue re-use / recycling and identifies associated benefits beyond elemental recovery. Furthermore, methodologies to translate risks and benefits into quantifiable data are discussed. Ultimately, such quantitative data are a prerequisite for facilitating decision-making regarding bauxite residue re-use / recycling and a stepping stone towards developing a zero-waste alumina production process.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Potential of biogas production to reduce firewood consumption in remote high-elevation Himalayan communities in Nepal(EDP Sciences, 25.08.2017) Gross, Thomas; Zahnd, Alex; Adhikari, Suman; Kaphre, Abhishek; Sharma, Subodh; Baral, Bivek; Kumar, Sunil; Hugi, ChristophRemote communities in the Nepalese mountains above 2500 m a.s.l. belong to the most precarious in the world. Inhabitants struggle for the minimum in terms of safe drinking water, food and sanitation. Reliable, affordable and clean energy for cooking, room heating and warm water for personal hygiene is often lacking and dependency on firewood very high. The remoteness and unlikeliness of electric grid connection in the coming decades make a diversified energy supply from renewable local resources crucial. Small-scale anaerobic digestion (AD) of organic substrates has been used for long in rural areas of developing countries to produce biogas as energy source and recover residue as organic fertilizer. AD is challenging at high elevations due to year around lower ambient temperatures and lower annual biomass production per area compared to lowlands. Nevertheless, examples of operational household AD exist even above 3000 m a.s.l. in the Andes. Here we compare firewood consumption with biogas potential from organic substrates in a community with 39 households at 3150 m a.s.l. in Jumla District, Nepal. In five households with varying numbers of members and animals kept, mean firewood use and its energy content per capita (cap) and day (d) were 2.1 kg or ca. 25 MJ in spring and 2.3 kg or ca. 28 MJ in winter. Easily available substrates include cow, sheep and horse dung from overnight shelters and human excrements from pit latrines, amounting on average to 1.7 kg wet weight (kgww) cap−1 d−1 in spring and 2.2 kgww cap−1 d−1 in winter. Adjusted to normal conditions (Nm3 at 0 °C, 1013.15 hPa), these substrates yielded on average 0.08 Nm3 cap−1 d−1 biogas in spring and 0.12 Nm3 cap−1 d−1 in winter (35–60% methane content) in biochemical methane potential (BMPs) tests at 36 °C. This could provide up to 60% of basic cooking needs on average and up to 75% in a “typical” household in terms of members and animals kept. Of the overall thermal energy needs including also room heating ca. 10–20% could be covered, substituting 0.1–0.4 (mean: 0.2) kg firewood cap−1 d−1. If only animal dung and human excrements are considered, no competition for resources arises as residues can still be used as organic fertilizer. This study supports the design and introduction of planned pilot digesters integrated into on-going community development including pit latrines for substrate availability, greenhouses as possible way of thermal insulation, and planned pico-hydropower plants to use excess electricity during the night for digester heating.01A - Beitrag in wissenschaftlicher Zeitschrift