Heretofore, in a dispersed energy supplying system, the unit cost of energy generated in houses and the unit rate of energy bought from an electric power company, etc. have been compared, but consideration has never been made of environmental burden.
There are provided a controlling portion 11 of controlling the operation of a fuel cell, a switch 30 of selectively supplying the electric power of the fuel cell or an external electric power into an electric power load, an electric power generation unit cost calculating portion 13 of calculating the electric power generation cost of the fuel cell, an electric rate system storing portion 14 of calculating the cost of a power plant 50 and a dispersed electric power generating apparatus 51, an LCA data storing portion 16 of storing LCA data of the fuel cell, the power plant 50 and the dispersed electric power generating apparatus 51, and a user interface portion 20 of presenting electric power generation cost, external electric power cost and LCA data and allowing the user to determine the controlling operation of the aforementioned controlling portion 11 and/or the selecting operation of the switch 11.