This paper aims to contribute to the introduction and promotion of the snow and ice energy in cold and heavy snowfall regions in the future. To achieve this goal, we have developed a new concept for improvement of the performance of a snow and ice energy system. We propose the high-density snow storage (HSS) system and the urban cold spring (UCS) for the purpose of efficient energy use and cost saving. The snow density of conventional snow storage systems is 450-550 kg/m(3). The high construction cost of these systems has been caused by a large space for the snow storage. The snow density is heightened to 750-800 kg/m(3) for the HSS system. UCS is the large HSS system for cities and communities. In 2002, HSS was applied to an actual office building in Oshu, Japan. The mass of stored snow was approximately 450 tonnes. The thermal insulation of snow storage room is 100-200 mm in thickness. Melt water is gathered in the cool water tank and is pumped to the heat exchanger. In 2003, space cooling was operated by using this HSS system. We evaluated the efficiency of storing snow and space cooling. (C) 2009 Elsevier B.V. All rights reserved.