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Leccisi, Enrica

Publications and source records attributed to Leccisi, Enrica.

8 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Updated sustainability status of cadmium telluride thin‐film photovoltaic systems and projections

This paper provides a comprehensive assessment of the up-to-date life-cycle sustainability status of cadmium-telluride based photovoltaic (PV) systems. Current production modules (Series 6 and Series 7) are analyzed in terms of their energy performance and environmental footprint and compared with the older series 4 module production and current single-crystalline Silicon (sc-Si) module production. For fixed-tilt systems with Series 6 modules operating under average US irradiation of 1800 kWh/m 2 /year, the global warming potential (GWP) is reduced from 16 g CO 2eq /kWh in Series 4 systems to 10 CO 2 eq /kWh in Series 6 systems. For operation in US-SW irradiation of 2300 kWh/m 2 /year, the GWP is reduced from 11 to 8 CO 2eq /kWh and for 1-axis tracking systems operating in Phoenix, Arizona, with point-of array irradiation of 3051 kWh/m 2 /year the GWP is reduced to 6.5 CO 2eq /kWh. Similar reductions have happened in all environmental indicators. Energy payback times (EPBT) of currently installed systems range from 0.6 years for fixed–tilt ground–mounted installations at average US irradiation at latitude tilt installations to 0.3 years for one-axis trackers at high US-SW irradiation, considering average fossil-fuel dominated electricity grids with fuel to electricity conversion efficiency of 0.3. The resulting energy return on energy investment (EROI) also depends on the conversion efficiency of the electricity grid and on the operation life expectance. For a 30-year operational life and grid conversion efficiency of 0.3, EROI ranges from 50 (at US average irradiation) to 70 for US-SW irradiation. The EROI declines with increased grid conversion efficiency; for CdTe PV operating in south California with grid conversion efficiency of 49%, the EROI is about 50 and is projected to fall to 30 when the state's 2030 target of 80% renewable energy penetration materializes. Material alternatives that show a potential of further reductions in degradation rates and materials for enhanced encapsulation that would enable longer operation lives have also been investigated. A degradation rate of 0.3%/year, which has been verified by accelerated testing, is assumed in 30-year scenarios; this is projected to be reduced to 0.2%/year in the near-term and potentially to 0.1%/year in the longer term. With such low degradation rates and enhanced edge-sealing, modules can last 40- to 50-years. Consequently, all impact indicators will be proportionally reduced while EROI will increase. This detailed LCA was conducted according to ISO standards and IEA PVPS Task 12 guidelines. Furthermore, the study revealed that the choices of system models, methods and temporal system boundaries can significantly impact the results and points out to the need to include assumptions regarding these choices in the “transparency in reporting” requirements listed in the IEA PVPS Task 12 Guidelines.

14 SOLAR ENERGY↗
DOE OSTI2023

Life-Cycle Analysis of Potentially Longer Life Expectancy CdTe PV Modules

Research on PV module longevity shows that with lower degradation rates and better encapsulation, PV modules can significantly outlast their current life expectancy of 25-30 years. The focus of this study is on alternative CdTe PV module back-contact and encapsulation materials that show the potential of increasing module operation lives from 30 to 40 and 50 years. Life-cycle-analyis shows that some alternative materials may slightly increase cradle-to-gate environmental impacts per m2 of module, but increased operational life more than counterbalances such impacts. The life-cycle carbn footprint of systems operating under average US insolation conditions of 1800 kWh/m2/yr is reduced from 10 gCO2eq/kWh to 6 gCO2eq/kWh when the operation life increases from 30 to 50 yrs. Similar reductions are noted for all life-cycle impact indicators, whereas the EROI of the considered system increases from 67 to 177 as life increases from 30 to 50 yrs.

14 SOLAR ENERGY↗
DOE OSTI2021

Life cycle energy demand and carbon emissions of scalable single-junction and tandem perovskite PV

Perovskite photovoltaics reached record efficiencies in the laboratory and, if sustainably commercialized, they would accelerate a green energy transition. Here, this article presents the development of life-cycle inventory material and energy databases of most promising four single-junction and three tandem scalable perovskite systems with assumptions regarding scalable production validated by industry experts. We conducted comprehensive “ex ante” Life Cycle Analysis (LCA) and Net Energy Analysis, analyzing their cumulative energy demand, global warming potential profiles, energy payback times and energy return on investment (EROI). LCA contribution analysis elucidates the most impactful material and process choices. It shows that solution-based perovskite manufacturing would have lower environmental impact than vapor-based methods, and that roll-to-roll (RtR) printing offers the lowest impact. Among material choices, MoOx/Al has lower impact than Ag, and fluorine-tin-oxide lower than indium-tin-oxide. Furthermore, we compare perovskites with commercial crystalline-silicon and thin-film PV, accounting for the most recent developments in crystalline-Si wafer production and differences in life expectancies and efficiencies. It is shown that perovskite systems produced with RtR manufacturing could reach in only 12 years of life the same EROI as that of single-crystalline-Si PV lasting 30-years. This work lays a foundation for sustainability investigations of perovskite large-scale deployment.

14 SOLAR ENERGY↗
DOE OSTI2020

Life-cycle environmental impacts of single-junction and tandem perovskite PVs: a critical review and future perspectives

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/m –2 , 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. Lastly, we discussed end-of-life (EoL) management options for resource recovery and for minimizing environmental impacts.

14 SOLAR ENERGY↗
DOE OSTI2019

Life Cycle Review of Scalable Perovskite Solar Cell Pathways

This paper presents estimations of life-cycle energy burden and potential environmental and health impacts of emerging scalable single-junction and tandem perovskite solar cells (PSC). Life cycle analysis (LCA) is the primary framework for assessing potential environmental impacts of new technologies, such as perovskites, and we expect that it would be used to guide improvements in industrial production in order to reduce life-cycle energy burden and environmental and health impacts. Thus, we identified the most promising single-junction and tandem PSC architectures, developing life-cycle inventories (LCIs) that include only materials and energy processes that can be scaled up from the lab- to industrial-scale production. Subsequently, LCA is applied to characterize, quantify and compare the resulting life-cycle impacts and comparisons are made with previously published results.

perovskites, Life Cycle Analysis, single-junction,↗
DOE OSTI2017

Energy Return on Energy Invested (ERoEI) for photovoltaic solar systems in regions of moderate insolation: A comprehensive response

A recent paper by Ferroni and Hopkirk (2016) asserts that the ERoEI (also referred to as EROI) of photovoltaic (PV) systems is so low that they actually act as net energy sinks, rather than delivering energy to society. Such claim, if accurate, would call into question many energy investment decisions. In the same paper, a comparison is also drawn between PV and nuclear electricity. We have carefully analysed this paper, and found methodological inconsistencies and calculation errors that, in combination, render its conclusions not scientifically sound. Ferroni and Hopkirk adopt 'extended' boundaries for their analysis of PV without acknowledging that such choice of boundaries makes their results incompatible with those for all other technologies that have been analysed using more conventional boundaries, including nuclear energy with which the authors engage in multiple inconsistent comparisons. In addition, they use out-dated information, make invalid assumptions on PV specifications and other key parameters, and conduct calculation errors, including double counting. Here in this paper, we provide revised EROI calculations for PV electricity in Switzerland, adopting both conventional and 'extended' system boundaries, to contrast with their results, which points to an order-of-magnitude underestimate of the EROI of PV in Switzerland by Ferroni and Hopkirk.

14 SOLAR ENERGY↗
DOE OSTI2016

The Energy and Environmental Performance of Ground-Mounted Photovoltaic Systems—A Timely Update

Given photovoltaics’ (PVs) constant improvements in terms of material usage and energy efficiency, this work 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/(m 2 ·yr)) to 2.8 years for sc-Si PV at low-irradiation (1000 kWh/(m 2 ·yr)), with corresponding quality-adjusted energy return on investment (EROI PE-eq ) values ranging from over 60 to ~10. Global warming potential (GWP) per kWh el averages out at ~30 g(CO 2 -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.

14 SOLAR ENERGY↗