Simplified method of regional resources and introduction potential assessments of geothermal heat pumps with borehole heat exchangers based on natural and social conditions is developed to compare resources and introduction potential among the regions and those of the other renewable energies. Natural condition is geological distribution, and social ones are the distribution of land use and heat demands. Resources are defined as heat energy extracted by borehole heat exchangers with 100 m length and 6m interval from all land area. Available resources are defined as heat energy extracted from building site area. The following three scenarios are established to calculate the introduction potential (hereinafter referred to as “potential”); scenario 1 is that 5% of the available resources can be extracted, scenario 2 is 20% and scenario 3 is 100%. The potential of three scenarios in each 1 km mesh is heat demands of residential and business districts or extractable resources, whichever is smaller.
Resources, available resources and potential are estimated in Akita, Saitama, Chiba, Tokyo, Kanagawa, Gifu, Aichi and Mie areas. Results show that available resources are greater in plain areas and smaller in mountain areas, although resources are greater in mountain areas and smaller in plain areas. Estimated potential of scenario 1 is in the range of 1.7×10⁴ to 6.1×10⁴ TJ/year in all areas. That of scenario 2 is 1.1×10⁵ to 1.6×10⁵ TJ/year in Saitama, Chiba, Tokyo, Kanagawa and Aichi, suggesting that the potential of scenario 2 greatly increases relative to that of scenario 1 in the areas with the big cities. The potential of scenario 3 is 3.0×10⁵ TJ/year in Tokyo, indicating that the distribution of potential of scenario 3 is strongly related to that of heat demands. The distribution pattern of the potential of scenario 3 is similar to that of the solar thermal energy.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract