In this study, the LCS database has been used to construct quantitative technology scenarios and a multi-region optimal power generation model considering stability. The target is to reduce 2013 CO₂ emissions from electricity power systems by 80% in 2050. In the scenario analysis, low cost renewable energy technological developments, energy conservation technologies and knowledge of stabilization of the electricity system were taken into account. The following results were obtained. Because of cost reduction of renewable energy technologies, CO₂ emission can be reduced by 80% in 2050 without additional cost. For this purpose, it is particularly important to develop technologies related to photovoltaic power generation, storage batteries and hot dry rock geothermal systems. In addition, energy saving also contributes to reducing power generation costs and improving system stability. Regarding future power grid system stability, it is thus extremely important to evaluate the technical issues of the low carbon electricity system.