2012 年 78 巻 787 号 p. 680-685
Micro grid system is attracting attention from the viewpoint of reduction of CO2 emission. Micro grid is composed of uncontrollable fluctuating power generation (e.g. photovoltaics and wind power generation) and controllable power generation (e.g. fuel-cell cogeneration system and gas engine cogeneration system). Micro grid can complement the variation in power from photovoltaics. And micro grid can raise the operating rate of co-generation system because of transmitting electricity between consumers mutually. However, operating rate of co-generation system is cut when photovoltaics are installed on micro grid system on a large scale. Hence we installed heat pump water heater on micro grid to adjust the electricity demands. We used a simulation to determine the reduction of CO2 emission at micro grid. In the simulation, we changed conditions: number of co-generation system, heat pump water heater and capacity of photovoltaics. We observed that micro grid has the optimal component ratio of cogeneration system and heat pump water heater.