Electric Energy Demand Analysis and Energy Management Indices of Solar Light Plant Factories

Abstract

We analyzed the electric energy consumption characteristics of two solar light plant factories set up in Kanto, which cultivated tomatoes using air-source heat pumps, and proposed energy management indices. More than 85 % of the energy consumption was attributed to heat pumps and it highly correlated with outside temperature. The index, “monthly electric energy consumption per unit surface area of cultivation facility” was effective throughout the year, and the management standard value of index was obtained based on outside temperature. For stable production period with heating, “monthly electric energy consumption per unit surface area/monthly yield per unit floor area” was effective. To improve the index, measures from energy conservation and cultivation were thought necessary.