Beyond yield: integrating energy, water, cost, and carbon to benchmark indoor vertical farming viability

Urban Farm DB summary

Filling a gap left by studies that assessed vertical-farming energy use and cost-effectiveness with simplified models, this paper isolates how individual input parameters drive efficiency, sustainability and economic viability using a detailed modelling framework with sensitivity and correlation analyses. It evaluates 162 scenarios combining three levels of temperature, photosynthetic photon flux density (PPFD) and CO2 concentration across the socio-environmentally distinct Trondheim, Shanghai and Dubai regions, at two insulation thicknesses. Because of HVAC and dehumidification, crop productivity stays optimal regardless of insulation or external climate. PPFD dominates growth (correlation 0.85), ahead of CO2 (0.36) and temperature (0.22), and also drives energy consumption (0.73). Lowest specific energy consumption coincides with lowest productivity (55 kg/m2), and the cheapest levelized cost of lettuce came at 24 degC, 250 umol/m2s PPFD, 1400 ppm CO2 with insulation (102 kg/m2). Only decarbonised energy systems can support vertical farming without raising CO2 emissions relative to imported lettuce.