Comparative Life Cycle Assessment of Inorganic and Organic PCM-Based Thermal Management in Photovoltaic Systems: A Case Study in Lebanon

PV panel overheating reduces their performance, and through the incorporation of phase change materials (PCMs) in passive cooling, the temperature impact is being reduced. This paper performs a comparative life cycle analysis (LCA) of four PCMs, i.e., sodium sulfate decahydrate, sodium phosphate dodecahydrate, decanoic acid, and calcium chloride hexahydrate, used in a PV cooling module. A cradle-to-grave life cycle assessment is carried out, taking one PCM-based cooling system that regulates one PV panel over 20 years of lifespan in Lebanon as the functional unit. The ReCiPe 2016 approach to estimate climate change ($\mathbf{k g ~ C O} \mathbf{C O}_{2}-\mathbf{e q}$), non-renewable energy (MJ), and water ($\mathrm{m}^{3}$) use was used. The results show that Sodium sulfate decahydrate yield the lowest impacts in the global warming potential, GWP ($0.643 \mathrm{~kg} \mathrm{CO}_{2}$-eq), while Sodium phosphate dodecahydrate yields the highest $(2.13 \mathrm{~kg}$ CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>-eq, $\sim 3 \times$ higher). Non-renewable energy demands and water usage were also compared. A study of uncertainty (1000-run Monte Carlo) confirms these rankings and discusses how differences in raw material availability and processing lead to these results and consider the implications for PV cooling in Lebanon. Overall, the readily available salt based PCMs (sodium sulfate and calcium chloride) offer a more sustainable cooling solution for PV panels, adding least carbon footprint to the PV panel among studied PCM but improving its performance. Conversely, bio-based organic PCMs carry higher burdens that may outweigh their benefits.