An Impact Evaluation of Introducing a CO₂ Reduction Surcharge and Storage Battery System on the Availability of Coal-fired Power Generation and CO₂ Emissions

Abstract

As the Japan’s feed-in tariff scheme, a renewable energy surcharge is charged in proportion to the grid power consumption. Authors proposed to replace this with a “CO₂ reduction surcharge” which is charged in proportion to CO₂ emissions. This paper evaluates nationwide effects of introducing this surcharge and storage battery when renewable energy is largely introduced. By optimizing hourly thermal power generation output of each type, PV/wind energy curtailment, charge/discharge amount and tie line power flow, the annual thermal power cost in Japan is minimized with linear programming methods. Then the CO₂ emissions and costs are evaluated. Results show the introduction of storage battery decreases PV/wind energy curtailment, but CO₂ emissions are not decreased because the energy share of coal-fired power generation is increased. When the surcharge unit price is increased, the availability and capacity of lower efficiency coal-fired power generation are decreased. Results also show that CO₂ emission intensity can be decreased to 0.2kg-CO₂/kWh when most of coal-fired plants are abolished, but then more capacity of LNG combined cycle power generation and more fuel costs are required.