Component Service Life Governs the Environmental Performance of Off-Grid Solar LED Street Lighting: A Scenario-Based Life Cycle Assessment

Autonomous photovoltaic (PV) LED street lighting is deployed worldwide as a low-carbon substitute for grid-connected lighting, and its environmental case is usually made on greenhouse gas emissions alone. This paper reports a component-resolved life cycle assessment of a complete off-grid lighting point, comprising a 300 Wp multicrystalline silicon module, a 9.25 kg lithium-ion pack and an LED luminaire, modelled in SimaPro with ecoinvent inventories and characterized with ReCiPe 2016, using a southern Mediterranean deployment as case study. Four scenarios test the variables available to a purchaser: supply-chain origin, manufacturing electricity mix, system configuration and component service life. Within the module, solar-grade silicon production alone contributes 52% of the endpoint score. Supply-chain origin is immaterial, since a six-fold difference in transport work alters the total by 1.5%, whereas a low-carbon manufacturing mix reduces it by 35%. Relative to a grid-connected luminaire the off-grid system lowers global warming by 62% and fossil resource scarcity by 76%, but raises mineral resource scarcity by 89%, terrestrial acidification by 106% and human non-carcinogenic toxicity by 73%, reducing the aggregate benefit to 15.5%. Once replacement over a 20-year infrastructure life is included, storage overtakes the module and becomes the largest contributor at 41%. Service life, not nominal efficiency or sourcing proximity, is the governing design variable.