Modelling Environmental Burdens of Indoor-Grown Vegetables and Herbs as Affected by Red and Blue LED Lighting

Notwithstanding that indoor farming is claimed to reduce the environmental pressures of food systems, electricity needs are elevated and mainly associated with lighting. To date, however, no studies have quantified the environmental and economic profile of Light Emitting Diodes (LED) lighting in indoor farming systems. The goal of this study is to quantify the effect of varying the red (R) and blue (B) LED spectral components (RB ratios of 0.5, 1, 2, 3 and 4) on the eco-effciency of indoor production of lettuce, chicory, rocket and sweet basil from a life cycle perspective. The functional unit of the assessment was 1 kg of harvested fresh plant edible product, and the International Reference Life Cycle Data System (ILCD) method was employed for impact assessment. Even though most of the materials of the LED lamp and electronic elements were imported from long distances (14,400 km), electricity consumption was the largest contributor to the environmental impacts (with the LED lamps being the main electricity consumers, approximately 70%), apart from the resources use indicator, where the materials of the lamps and the mineral nutrients were also relevant. RB0.5 was the most energy-effcient light treatment but had the lowest eco-effciency scores due to the lower crop yields. This project received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 708672. The elaboration of the manuscript was also supported by a grant from the Fundacion Séneca (reference 20555/IV/18, Call for Fellowships for Guest Researcher Stays at Universities and OPIS of the Region of Murcia) awarded to Francesco Orsini.