Energy consumption as the main challenge faced by indoor farming to shorten supply chains

Abstract

Controlled environment agriculture is developing rapidly to shorten supply chains and reduce the energy and greenhouse gas intensity of products transportation to consumers. However, compared to conventional value chains, these benefits are counter-acted by a higher energy consumption at the farm stage. Few studies have addressed this trade-off because of the novelty of controlled environment systems and the lack of suitable data to assess them. Benchmarking this new industry against its current counterfactuals is nevertheless critical and may point to potential options to mitigate its impacts.

This study aimed to bridge this gap by evaluating the environmental performance of an urban vertical, indoor farm through life-cycle assessment. The farm, located near Paris, France, uses aeroponic towers to grow plants usually sourced from tropical countries for use in high-added-value cosmetic products. The analysis covered the whole production cycle up to the processing plant gate and involved three species: Ocimum sanctum, Centella asiatica and Coleus forskohlii.

Climate change impacts amounted 9.7 kg CO₂-eq./kg of plant biomass, as averaged across all crops, with large differences between species. These emissions were 4-fold larger than those of the air-imported, conventional chain for Centella Asiatica. On-farm electricity consumption contributed 60% of the carbon footprint. Sensitivity analysis showed that optimal farming processes could significantly reduce environmental impacts. Other beneficial trade-offs associated with local production, such as national employment, easier supply chain management, and quality of active ingredients, should be factored in for a comprehensive assessment of indoor farms.