Field measurements and analyses for a hybrid system for snow storage/melting and air conditioning by using renewable energy

Abstract

This paper aims to propose a hybrid system for snow storage/melting and air conditioning by using renewable energy-resources, and clarify the effects of an actual realized application. First, the outline of the system installed at an office building, which was completed in Sapporo, Japan in 2001, is shown. The hybrid system is composed of an underground thermal utility for snow melting by using vertical earth heat-exchangers and space cooling through seasonal cold storage of snow-and-ice cryogenic energy. Second, at the comparatively severe climatic conditions (the lowest outside air-temperature −9.2 °C and the amount of daily snowfall 8.1 cm), it was found that the underground thermal utilization system contributes to preventing freezing of a road surface, and that the road-surface exposure rate was approximately 90%. The effectiveness of this system on energy conservation, environmental protection and cost was verified through numerical analyses. Also, as a result of measuring snow-storage characteristics and space-cooling performance, the effective amount of snow stored on the first day of the space-cooling period was approximately 74%, which gave comparatively good agreement with the predicted value.