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We quantified the environmental and energy life-cycle impacts of a mechanically-stacked perovskite-silicon tandem (Pk/Si) photovoltaic systems – under development by Tandem PV, Palo Alto, California – in comparison with commercial PV systems. It was found that the considered systems would be less energy demanding and would produce less carbon and toxic emissions than crystalline-based and CIGS systems, if they reach the same 30-year life as conventional PV systems. Sensitivity analysis on lifetimes shows that even when they last 20 years their energy and environmental performances are comparable to those of single-junction c-Si and CIGS systems. The Energy Pay Back Times (EPBT) of Pk/Si tandem systems were estimated to range from 5 months (installations at 1,800 kWh/m2/yr) to 4 months (installations at 2,300 kWh/m2/yr).

Lead halide perovskites (LHP) are an emerging class of photovoltaic (PV) materials that have drawn intense interest due to their power conversion efficiencies above 23% and their potential for low-cost fabrication. However, the toxicity of lead causes concern about its use in LHP-PV at large scales. Here, we quantified lead intensity and toxicity potential of LHP-PV in potential commercial production. Lead intensity in LHP-PV life cycles can be 4 times lower and potential toxic emissions can be 20 times lower than those in representative U.S. electricity mixes, assuming that PV operational lifetimes reach 20 years. We introduce the metric “toxicity potential payback time”, accounting for toxic emissions in the life cycle of energy cycles, and showed that it is

Chile is one of the fastest-growing economies in Latin America, with a mainly fossil fuelled electricity demand and a population projected to surpass 20 million by 2035. Chile is undergoing a transition to renewable energies due to ambitious national targets, namely to generate 60% of its electricity from local renewable energy by 2035, and to achieve a 45%renewable energy share for all new electric installed capacity. In this work, we present a comprehensive energy analysis of the electricity generation technologies currently deployed in Chile. Then, we analyse potential future scenarios, considering a large deployment of RE, mainly PV and wind, to replace coal-fired electricity. The life cycle assessment (LCA) and net energy analysis (NEA) methods are applied in parallel to provide complementary indicators, respectively nr-CED and EROI, and identify weak spots and future opportunities. Special focus is given to the effect on EROI of transporting fossil fuels to Chile. Results show that a large deployment of PV and wind can significantly improve the overall net energy performance of electricity generation in Chile, while leading to an electricity supply mix that is >60% less reliant on non-renewable energy.

The increasing contribution of renewable energies to electricity grids in order to address impending environmental challenges implies a reduction in non-renewable resource use and an alignment with a global transition toward a low-carbon electric sector. In this paper, four future UK grid mix scenarios with increased photovoltaic (PV) installed capacity are assessed and compared to a benchmark “Low PV” scenario, from 2016 to 2035. The complexity of the issue requires a multi-disciplinary approach to evaluate the availability of net energy, environmental aspects and technical performance. Hence, the comparison between scenarios includes short-term and long-term energy metrics as well as greenhouse gas (GHG) and technical metrics. Also, the paper considers the viewpoints offered by both an “integrative” and a “dynamic” approach to net energy analysis. Results for all five analysed scenarios indicate that increased PV deployment will not be detrimental to the UK grid performance from the points of view of a wide range of system-level technical (% renewable energy curtailment to ensure grid stability), energy (energy return on investment and non-renewable cumulative energy demand) and environmental (greenhouse gas emissions) metrics.

This paper investigates the most commonly proposed organic-inorganic lead halide perovskite solar cell (PSC) architectures in terms of their potential life-cycle environmental impacts. We critically review the validity of assumptions and the results of previously published studies. As great challenges remain in scaling up devices from laboratory scale to large-area module manufacturing, we focus this investigation on materials and processes that have a good scalability potential and minimum possible environmental footprints. Thus, we calculate and compare PSC prospective environmental life-cycle impacts in terms of global warming potential (GWP) and acidification potential (AP) while assessing the scalability of associated manufacturing processes.

We performed a comprehensive and internally consistent assessment of the energy performance of the full range of electricity production technologies in the United Kingdom, integrating the viewpoints offered by net energy analysis (NEA) and life cycle assessment (LCA). Specifically, the energy return on investment (EROI), net-to-gross energy output ratio (NTG) and non-renewable cumulative energy demand (nr-CED) indicators were calculated for coal, oil, gas, biomass, nuclear, hydro, wind and PV electricity. Results point to wind, and to a lesser extent PV, as the most recommendable technologies overall in order to foster a transition towards an improved electricity grid mix in the UK, from both points of view of short-term effectiveness at providing a net energy gain to support the multiple societal energy consumption patterns, and long-term energy sustainability (the latter being inversely proportional to the reliance on non-renewable primary energy sources). The importance to maintain a sufficient installed capacity of readily-dispatchable gas-fired electricity is also recognised.

For new technologies, such as perovskite solar cells (PSC), life cycle analysis (LCA) offers a fundamental framework for examining potential environmental, energy and health impacts and mitigation options before large-scale commercialization and for guiding improvements in development and production that further reduce their environmental footprint. However, credible LCA studies require actual process-based material, energy and emissions data, which may not exist before the technologies are commercially produced. Thus, the perovskite LCA literature is based on linear extrapolations of laboratory data. In this paper we critically reviewed the PSC LCA literature, explain the reasoning for a wide divergence of results, and determined which data apply to scalable industrial production, materials and processes. Our investigation probed into the formulation of each layer of a PSC device, and its potential for industrial scale fabrication. We found that electricity use is the main contributor to reported LCA results, explaining the large difference, ranging from 7.78 kWh to 1,460 kWh/m2, among various studies. Subsequently, we identified and discuss methodological errors in some of these estimates. In terms of life-cycle toxicity most of the reviewed LCA studies do not attribute any major overall toxicity impact to the presence of lead in the PSC devices. We also reviewed and critiqued studies describing "worst-case" scenarios of accidental release of lead into the environment, and, in spite of statements in those studies, we found them to be inconclusive. Finally, we discussed end-of-life (EoL) management options for resource recovery and for minimizing environmental impacts.

This paper investigates the implications of transitioning to more renewable electricity generation in Chile. The ongoing aggressive penetration of renewable energies in Chile reflects the large availability of solar, and to a lesser extent, wind-resources, and is a product of the ambitious national target to generate 60% of Chilean electricity from renewable sources by 2035. In addition, the electricity demand in Chile is expected to keep increasing over the next decades, and there are concerns about security of energy supply. We applied Net Energy Analysis (NEA) from a dynamic perspective, using a new metric, referred to as Power Return on Investment (PROI), which complements the information provided by the conventional Energy Return on Investment (EROI). We illustrated the methodological differences between these two indicators in terms of the direct electricity output, and equivalent primary energy. Results focus on photovoltaics (PV), and indicate significant opportunities for their large deployment, up to 40% of total electricity generation in the Chilean electric grids in 2035. Specifically, the PROI PE-eq trends of PVs, which quantify the year-by-year “energy cost” associated to the renewable energy transition, improve significantly over the course of less than two decades in both our future scenarios (respectively, 10-fold in the “best case”-and 6fold in the “worst case”).

Solar photovoltaic (PV) electricity has the potential to be a major energy solution, sustainably suitable for urban areas of the future. However, although PV technology has been projected as one of the most promising candidates to replace conventional fossil based power plants, the potential disadvantages of the PV panels end-of-life (EoL) have not been thoroughly evaluated. The current challenge concerning PV technology resides in making it more efficient and competitive in comparison with traditional fossil powered plants, without neglecting the appraisal of EoL impacts. Indeed, considering the fast growth of the photovoltaic market, started 30 years ago, the amount of PV waste to be handled and disposed of is expected to grow drastically. Therefore, there is a real need to develop effective and sustainable processes to address the needed recycle of the growing number of decommissioned PV panels. Many laboratory-scale or pilot industrial processes have been developed globally during the years by private companies and public research institutes to demonstrate the real potential offered by the recycling of PV panels. One of the tested up lab-scale recycling processes – for the crystalline silicon technology – is the thermal treatment, aiming at separating PV cells from the glass, through the removal of the EVA (Ethylene Vinyl Acetate) layer. Of course, this treatment may entail that some hazardous components, such as Cd, Pb, and Cr, are released to the environment, therefore calling for very accurate handling. To this aim, the sustainability of a recovery process for EoL crystalline silicon PV panels was investigated by means of Life Cycle Assessment (LCA) indicators. The overall goal of this paper was to compare two different EoL scenarios, by evaluating the environmental advantages of replacing virgin materials with recovered materials with a special focus on the steps and/or components that can be further improved. The results demonstrate that the recovery process has a positive effect in all the analyzed impact categories, in particular in freshwater eutrophication, human toxicity, terrestrial acidification and fossil depletion indicators. The main environmental benefits arise from the recovery of aluminum and silicon. In particular, the recovered silicon from PV waste panels would decrease the need for raw silicon extraction and refining in so lowering the manufacturing costs, and end-of-life management of PV panels. Moreover, the amount of the recovered materials (silicon, aluminum and copper, among others) suggests a potential benefit also under an economic point of view, based on present market prices.

Given photovoltaics’ (PVs) constant improvements in terms of material usage and energy efficiency, this paper provides a timely update on their life-cycle energy and environmental performance. Single-crystalline Si (sc-Si), multi-crystalline Si (mc-Si), cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS) systems are analysed, considering the actual country of production and adapting the input electricity mix accordingly. Energy pay-back time (EPBT) results for fixed-tilt ground mounted installations range from 0.5 years for CdTe PV at high-irradiation (2300 kWh/(m2·yr)) to 2.8 years for sc-Si PV at low-irradiation (1000 kWh/(m2·yr)), with corresponding quality-adjusted energy return on investment (EROIPE-eq) values ranging from over 60 to ~10. Global warming potential (GWP) per kWhel averages out at ~30 g(CO2-eq), with lower values (down to ~10 g) for CdTe PV at high irradiation, and up to ~80 g for Chinese sc-Si PV at low irradiation. In general, results point to CdTe PV as the best performing technology from an environmental life-cycle perspective, also showing a remarkable improvement for current production modules in comparison with previous generations. Finally, we determined that one-axis tracking installations can improve the environmental profile of PV systems by approximately 10% for most impact metrics.