3:47 PM - 4:02 PM
[MZZ47-03] Assessment of snow and ice cryogenic energy potential in Hokkaido: a case study in Niseko Town
Keywords:snow and ice cryogenic energy, endowment, import snow, carbon dioxide, full cost
With the frequent occurrence of extreme weather events and disasters on a global scale due to global warming, there is a need to reduce greenhouse gas (GHG) and achieve a decarbonized society. In September 2018, the people of Hokkaido, Japan experienced a power outage throughout Hokkaido due to the Hokkaido Eastern Iburi Earthquake. Therefore, in an emergency, the centralized power supply system is considered to be vulnerable, and it is recognized that research and development for the utilization of locally produced and locally consumed energy distributed in each region and the promotion of energy mix are important. The purpose of this study is to evaluate the effective utilization of snow and ice cryogenic energy, which is characteristic regional energy of Hokkaido. As a case study, we focused on Niseko Town, which is selected as "Environmental Future City" and "SDGs Future City".
In this study, the electric storage facilities operated mainly by fossil fuel sources and the snow storage facilities using snow and ice cryogenic energy were compared in terms of both environmental and economic aspects. GHG emissions were regarded as an environmental index, and life cycle assessment (LCA) was applied to assess the environmental aspect. The Japanese version of the damage calculation type impact assessment method (LIME2), which is one of the life cycle impact assessment (LCIA) methods, was used for quantitative evaluation of the environmental impacts. Moreover, the total cost (economic / environmental cost) was regarded as an economic index, and the full cost accounting (FCA) was used as the evaluation method. The internal and external cost was calculated using the life cycle cost (LCC) and LCIA, and these were added up to evaluate the total cost. The LCA calculation software MiLCA 2.2.1.0 (2019) and the LCI database IDEA v2 (2019) were used for the calculation.
The total GHG emissions associated with the construction, use and disposal of snow storage facilities were estimated to be 130t-CO2eq per year. Assuming that the environmental cost associated with CO2 emissions is 2.33 (yen / kg-CO2), the cost of damage to the environment is estimated to be 303,000 yen / year. As a result of the interview survey, the construction cost and operation cost of the snow storage facility were calculated to be 180 million yen and 3.25 million yen, respectively. In addition, the cost of disposing the facility was estimated to be 60 million yen based on the market price of the demolition cost of steel-framed reinforced concrete buildings in Hokkaido (about 21,000 yen per m2). These values were divided by the useful life span of the snow storage facility (21 years) to calculate each cost per year. The construction cost of snow storage facility accounts for 60% of the total costs, and therefore, the economic efficiency is considered to be highly dependent upon the amount of initial investment.
This study suggests that there is an advantage in utilizing snow and ice cryogenic energy in the heavy snowfall areas, because the amount of GHG emissions and the transportation costs in the process of collection and delivery can be suppressed substantially. On the other hand, considering that half of the total GHG emissions and total costs of using the snow storage facility are caused by the construction process of the facility , it is suggested that further innovation in constructing the snow storage facility is necessary to sufficient reduction of both CO2 emission and costs.
In this study, the electric storage facilities operated mainly by fossil fuel sources and the snow storage facilities using snow and ice cryogenic energy were compared in terms of both environmental and economic aspects. GHG emissions were regarded as an environmental index, and life cycle assessment (LCA) was applied to assess the environmental aspect. The Japanese version of the damage calculation type impact assessment method (LIME2), which is one of the life cycle impact assessment (LCIA) methods, was used for quantitative evaluation of the environmental impacts. Moreover, the total cost (economic / environmental cost) was regarded as an economic index, and the full cost accounting (FCA) was used as the evaluation method. The internal and external cost was calculated using the life cycle cost (LCC) and LCIA, and these were added up to evaluate the total cost. The LCA calculation software MiLCA 2.2.1.0 (2019) and the LCI database IDEA v2 (2019) were used for the calculation.
The total GHG emissions associated with the construction, use and disposal of snow storage facilities were estimated to be 130t-CO2eq per year. Assuming that the environmental cost associated with CO2 emissions is 2.33 (yen / kg-CO2), the cost of damage to the environment is estimated to be 303,000 yen / year. As a result of the interview survey, the construction cost and operation cost of the snow storage facility were calculated to be 180 million yen and 3.25 million yen, respectively. In addition, the cost of disposing the facility was estimated to be 60 million yen based on the market price of the demolition cost of steel-framed reinforced concrete buildings in Hokkaido (about 21,000 yen per m2). These values were divided by the useful life span of the snow storage facility (21 years) to calculate each cost per year. The construction cost of snow storage facility accounts for 60% of the total costs, and therefore, the economic efficiency is considered to be highly dependent upon the amount of initial investment.
This study suggests that there is an advantage in utilizing snow and ice cryogenic energy in the heavy snowfall areas, because the amount of GHG emissions and the transportation costs in the process of collection and delivery can be suppressed substantially. On the other hand, considering that half of the total GHG emissions and total costs of using the snow storage facility are caused by the construction process of the facility , it is suggested that further innovation in constructing the snow storage facility is necessary to sufficient reduction of both CO2 emission and costs.