Optimizing Plant Factory Performance for Local Requirements

Abstract

Abstract Trends in food, innovations in the food supply chain, and the resulting opportunities for a profitable vertical farming business are rather region-specific. For example, while in the United States and Canada the focus is mostly on the local perspective (local-for-local), in Europe there is a focus on optimizing yield and quality, and in Japan the focus is predominantly on food safety and maturing the production technology. In this overview, we will outline the main reasons for these differences and the opportunities for plant factories to further optimize their operations by focusing on the most critical factors to grow efficiently. To improve the efficiency and the economic viability of plant factories, it helps, as a community, to use a set of shared key performance indicators (KPIs). Examples of such KPIs are the lighting system efficiency, the light utilization in terms of the fraction of light generated that is actually absorbed by the plants, and the light-use-efficiency (i.e., the growth efficiency as expressed in grams of biomass production per mole of light offered to the plants (g\xa0mol–1)). In this overview, we present a set of KPIs, their status, how they can be improved, and to what level they can be expected to improve. We show how some KPIs can be improved by an optimal lighting design, a crop transplanting strategy, and choice of crop variety. We present a model to estimate the theoretical maximum g\xa0mol–1 achievable. We illustrate our approach with specific examples of what we achieved for lettuce growth and the growth of several types of herbs.