Experimental life cycle assessment of container-based vertical farming of chili pepper under two light intensities and three energy supply scenarios

Vertical indoor farming (VIF) is recognized as a resilient production method, however, its environmental performance is significantly limited by electricity demand. To provide experimentally validated evidence for fruiting crops, this study combines cultivation data from chili pepper grown at two photosynthetic photon flux densities (250 and 500 μmol m -2 s -1 ) in a VIF container with a life cycle assessment of three distinct energy supply scenarios. Doubling the light intensity raised annual dry yield by 57% to 3.1 kg DW m -2 a -1 but decreased light-use efficiency by 27%. System-level energy and water use remained similar across treatments at 922 kWh kg DW -1 and 14 L kg DW -1 respectively. With a fossil-based electricity mix, climate impact reached 74 kg CO 2 -eq kg FW -1 , primarily due to lighting and cooling. Adjusting the light intensity or expanding the cultivation area within the VIF container only marginally reduced this impact. In contrast, utilizing renewable electricity with industrial waste-heat cooling reduced the impact to 3.9 kg CO 2 -eq kg FW -1 , comparable to upper range values reported for tomato high-tech greenhouse systems. These findings demonstrate that the environmental performance of fruiting-crop vertical farms is mainly determined by the energy source rather than cultivation intensity or layout, underscoring the importance of integrating energy systems to improve sustainability outcomes. • Dwarf pepper as fruiting crop in container vertical farming • LCA based on experimental data gained in container vertical farm • Energy sourcing drives climate impacts in container vertical farming • Higher light intensity boosts yield, but emission cuts remain marginal • Renewable electricity and waste-heat cooling cut carbon footprint by up to 94%.