An evaluation of CO₂emission reduction by EV and FCV introduction considering stable and economical power system operation

To reduce CO₂emissions in transport sector, it is a hopeful way to replace gasoline vehicles (GV) by electric vehicles (EV) and fuel cell vehicles (FCV). However, the reduction is largely affected by CO₂emission intensity of power system and the way to make hydrogen. Authors simulate a power system in 2030 where a large amount of PV is implemented and 16% of PV generated energy must be curtailed. The annual cost is minimized by optimizing the hourly output of coal fired and LNGCC plants, when the 16% of passenger GV mileage is replaced by EV charged at midnight and/or daytime. In FCV case, the capacity of water electrolysis and hydrogen tank, and the hourly electrolysis output as well as thermal power output are optimized. Results show CO₂emissions decrease particularly when EVs are charged at daytime using a part of surplus PV energy and the charging power is controlled to contribute frequency stability. The electrolysis demand decreases the PV energy curtailment but increases the CO₂emission because of the lower energy converting efficiency and higher facility cost. Constraint conditions of the minimum ratio of non-synchronous generation and frequency control ability affect the results too.