Applying data envelopment analysis (DEA) to improve energy efficiency of apple fruit, focusing on cumulative energy demand

Abstract

Analysis of energy consumption provides useful information for planners and policymakers to improve the efficiency of energy consumption. Given the energy crisis which caused by the consumption of non-renewable resources in agriculture sector, a lot of attempts have been made to reduce the energy consumption of inputs as much as possible. The goal of this study is to evaluate the energy efficiency and determine the optimal pattern of input consumption and improve the efficiency in apple orchards. Based on the simple random sampling method and Cochran equation, sample size was determined as 30. Based on the results, inputs energy and output were obtained as 73092 and 59537 MJ ha-1, respectively and electricity was identified as major contributor to total energy consumption with the share of 37.91% (277707 MJ ha-1). Energy efficiency (ER), energy productivity (EP) and specific energy (SE) were determined as 0.82, 0.43 kg MJ-1 and 2.36 MJ kg-1, respectively. Results showed that the total amount of cumulative energy demand is 32159.92 MJ tonne-1 for five environmental impact categories, of which non-renewable fossil resources had highest contribution to total cumulative energy demand (98%). Based on data envelopment analysis (DEA) results and using constant returns to scale (CRS), 9233 MJ ha-1 of energy could be saved, means that applying DEA can mitigate energy consumption up to 12.6% in apple orchards. Also after optimization of energy flow in orchards, energy ratio and energy productivity were improved as 12.76% and 14%, respectively.