This paper provides a comprehensive assessment of the current life-cycle sustainability status of crystalline-based photovoltaic (PV) systems. Specifically, single-crystalline Si (sc-Si) and multicrystalline Si (mc-Si) PV systems are analyzed in terms of their environmental and energy performance, providing breakdown contributions and comparisons with estimates published 6 years ago. Results clearly show the significant environmental improvement in the sc-Si PV system production—mainly at the wafer stage—for which the impacts have been reduced by up to 50% in terms of carbon emissions and 42% in terms of acid gas emissions. The life-cycle cumulative energy demand is estimated to be approximately 48% lower (for sc-Si) and 24% lower (for mc-Si) than previously reported estimates. Energy payback times of currently installed systems range from 1.3 (for c-Si PV) and 1.5 years (mc-Si PV) for fixed-tilt ground-mounted installations at low irradiation (1000 kWh/m²/year), to 0.6 years at high irradiation (2300 kWh/m²/year). The resulting energy returns on investment—expressed in terms of primary energy—range from 22 (at low irradiation) to 52 (at high irradiation) for sc-Si PV systems and from 21 to 47 for mc-Si PV systems. Furthermore, we examine the effects of cleaner electricity grids and grid efficiency improvements on these environmental and energy indicators.

中文翻译：

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基于晶体硅的光伏系统的更新可持续性状态：生命周期能源和减少环境影响的趋势

本文对基于晶体的光伏 (PV) 系统当前的生命周期可持续性状态进行了全面评估。具体而言，我们分析了单晶硅 (sc-Si) 和多晶硅 (mc-Si) PV 系统的环境和能源性能，提供击穿贡献并与 6 年前发布的估计值进行比较。结果清楚地表明，sc-Si 光伏系统生产中的环境显着改善（主要是在晶圆阶段），碳排放的影响减少了 50%，酸性气体排放的影响减少了 42%。生命周期累积能源需求估计比先前报告的估计值低约 48%（对于 sc-Si）和 24%（对于 mc-Si）。当前安装的系统的能源回收时间范围为 1。² /年），在高辐照（2300 kWh/m ² /年）下为 0.6 年。由此产生的投资回报——以一次能源表示——范围从 22（低辐照）到 52（高辐照），对于 sc-Si PV 系统，从 21 到 47，对于 mc-Si PV 系统。此外，我们还研究了更清洁的电网和提高电网效率对这些环境和能源指标的影响。