Cu(InGa)Se 2 THIN-FILM SOLAR CELLS: COMPARATIVE LIFE-CYCLE ANALYSIS OF BUFFER LAYERS

ABSTRACT: A motivation for replacing the current CdS buffer layer in CIGS PV is to avoid potential environmental-and human-health risks related to cadmium compounds. However, to gain a full perspective, such risks should be evaluated throughout the entire life cycle of the CdS, and also of alternative buffer layers. Based on data from the National Renewable Energy Laboratory and Global Solar Energy, we examined the life-cycle Cd emissions during materials production and the deposition processes for CdS and ZnS buffers. We found that the Cd emissions from the buffer layers are minimal compared to the upstream emissions from fossil-fuel-based electricity that the electricity generated from CIGS PV will replace. Accordingly, assuring a higher efficiency of CIGS PV is the best strategy to minimize Cd emissions to the environment In addition, the production of ZnS (and InS) entails some Cd emissions as Cd is present in Zn ores. Based on the current efficiencies of alternative cell designs, CIGS/CdS will create a smaller amount of net Cd emissions than the CIGS/ZnS or CIGS/InS-based alternatives

What are the energy and environmental impacts of adding battery storage to photovoltaics? A generalized life cycle assessment

Renewable electricity generation is intermittent and its large‐scale deployment will require some degree of energy storage. Although best assessed at grid level, the incremental energy and environmental impacts of adding the required energy storage capacity may also be calculated specifically for each individual technology. This paper deals with the latter issue for the case of photovoltaics (PV) complemented by lithium‐ion battery (LIB) storage. A life cycle assessment (LCA) of a 100MW ground‐mounted PV system with 60MW of (lithium‐manganese oxide) LIB, under a range of irradiation and storage scenarios, show that energy pay‐back time and life‐cycle global warming potential increase by 7% to 30% (depending on storage duration scenarios), with respect to those of PV without storage. Thus the benefits of PV when displacing conventional thermal electricity (in terms of carbon emissions and energy renewability) are only marginally affected by the addition of energy storage

A Comprehensive Guide to Solar Energy Systems With Special Focus on Photovoltaic Systems

This book, the most advanced and research focused text on all aspects of solar energy engineering, is a must have edition on the present state of solar technology, integration and worldwide distribution. In addition, the book provides a high-level assessment of the growth trends in photovoltaics and how investment, planning and economic infrastructure can support those innovations. Each chapter includes a research overview with a detailed analysis and new case studies that look at how recent research developments can be applied. Written by some of the most forward-thinking professionals, this book is an invaluable reference for engineers. Key Features Contains analysis of the latest high-level research and explores real world application potential in relation to developments Uses system international (SI) units and imperial units throughout to appeal to global engineers Offers measurable data written by a world expert in the field on the latest developments in this fast moving and vital subject Readership Energy engineers, researchers, graduate students, professors and lecturers in Engineering, scientists and engineers working in energy, industrialists and engineers working in future energy development

Pathways for minimal and zero liquid discharge with enhanced reverse osmosis technologies: Module-scale modeling and techno-economic assessment

While mechanical vapor compression is typically applied for the concentration of brine, new approaches that are less costly and less energy intensive are needed to facilitate minimal and zero liquid discharge. Several variations of reverse osmosis for high-salinity desalination and increasing recovery rates beyond the pressure limitation of conventional RO have been proposed in the literature. The promise of these enhanced RO approaches entails a reduction in energy consumption when compared with thermal desalination methods. In this paper, low-salt rejection reverse osmosis (LSRRO), cascading osmotically mediated reverse osmosis (COMRO), and osmotically assisted reverse osmosis (OARO) were comparatively assessed via module-scale, cost optimization models to gain an accurate perspective of the performance differences between each of these configurations. We quantified the optimal levelized cost of water (LCOW) of each technology for the case of desalinating feedwater at 70 g/L at 75% recovery, which would result in a brine concentration near 250 g/L, a level that allows further treatment with crystallizers. For baseline scenarios, LCOW results for LSRRO, COMRO, and OARO were 6.63, 7.90, and 5.14 $/m3 of product water, respectively, while the corresponding specific energy consumption (SEC) values were 28.9, 12.8, and 10.3 kWh/m3. A sensitivity analysis is also presented

Life cycle impact analysis of cadmium in CdTe PV production

This paper describes the material flows and emissions in all the life stages of CdTe PV modules, from extracting refining and purifying raw materials through the production, use, and disposal or recycling of the modules. The prime focus is on cadmium flows and cadmium emissions into the environment. This assessment also compares the cadmium environmental inventories in CdTe PV modules with those of Ni-Cd batteries and of coal fuel in power plants. Previous studies are reviewed and their findings assessed in light of new data.Cadmium emissions Photovoltaics Solar cells Cadmium telluride Life cycle analysis Emissions allocation