A Study on Buying Price of Photovoltaic Electricity under Carbon Tax Regime

Abstract

Assuming that photovoltaic (PV) systems are prevailing in residential houses under carbon tax regime, an economic performance of PV systems is investigated from standpoint of an electric utility. The economic performance is estimated with a buying price of PV electricity and a PV economic index which is defined by ratio of the buying price to the cost of generation of the electric utility. Because these values depends on electric power development and operation, the best mix and the operation of power plants are obtained by the linear programming under restrictions on power generation. Then, the buying price of PV electricity is calculated from the total cost of the electric utility. The buying price means the upper limit under which the electric utility never suffers a loss. Moreover, the buying price is compared with the power generation cost. Parameters are the prevalence attainment ratio of PV system (0_??_00%), the upper limit of newly-developed nuclear power plant (0_??_4 GW/10y) and the generated energy ratio of coal thermal plant (0_??_15%). Chubu Electric Power Company, Inc. is adopted as the electric utility. The calculation results show that the buying price of PV electricity increases linearly with increasing of the carbon tax rate and its values are 9 and 11.5 yen/kWh when the carbon tax rate are 0 and 25 thousand yen /t-C, respectively, which does not affected with the prevalence attainment ratio of PV system and the upper limit of newly-developed nuclear power plant. It is not the carbon tax rate but the newly-developed nuclear power plant that influences on the PV economic index. The values of the PV economic index are 1.35_??_1.45 and 1.50_??_1.60 when the newly-developed nuclear power plant are 0 and 4 GW/10y, respectively. These results show that the economic performance of PV system is increased by developing the nuclear power plant at a certain rate and introducing the carbon tax.