Analysis of energy conservation by roof shade installations in refrigerated container areas

The gap between research and application is a challenge for port decision makers, as studies on empirical findings on energy saving and decarbonization measures for ports, especially for reefer containers, which account for a large share of energy consumption, are scarce. In this study, we focus on the roof shades for reefer containers as an energy-saving measure, and develop a versatile simulation method predicting the surface temperature of container walls using computational fluid dynamics, and examine the feasibility of introducing roof shades based on an economic analysis. Consequently, the effectiveness of the simulation method was confirmed by comparison with experimental results from Hakata Port, Japan, and it was estimated that the percentage of energy saved by installing roof shades was 13–20% and the power consumption charges would decrease by approximately 4.82%. However, it was also revealed that introducing the roof shade system was challenging because of the high installation cost compared to the profit from energy conservation, thereby necessitating government support in social implementation. The results of this study are expected to provide powerful tools for decision makers in ports for preliminary evaluation of roof shade implementation, thereby contributing to the energy conservation and decarbonization of ports around the world. •A simulation model was developed to verify the effect of introducing roof shades to reefer areas.•The percentage of energy saved by roof shades is estimated to be 13–20%.•Energy savings by roof shades are higher in winter and lower in summer.•The power consumption charges decrease by approximately 4.82%.•Government support is needed because of the small cost-benefit ratio of roof shade systems.