Evaluation of Electric Vehicles based on Long-term Travel Activity Data of Passenger Cars

This study aimed to clarify whether currently available electric vehicles (EVs) could feasibly match the performance of gasoline-powered passenger cars with respect to the actual travel activity data collected for 18 gasoline-powered cars over the years 2006 and 2007 in Tsukuba in Japan. We examined 3 types of EV of different vehicle size and battery capacity, and calculated the running energy of each based on the vehicle specifications and actual speed pattern data. Auxiliary energy consumption such as that required for headlights at nighttime and air-conditioning on hot or cold days was added to the running energy. Supposing charging ability of 100V and 8A at home, when the energy consumed during a day did not exceed the initial available energy of the battery, we determined that the EV could replace a gasolinepowered vehicle for that day. Our calculations showed that an EV with a 9 kWh battery could completely replace only 1 of the 18 cars, and EVs with a 16 or 24 kWh battery could completely replace only 3 more. However, we found that an EV with a 16 or 24 kWh battery could replace 17 out of the 18 cars if we accept that we may not be able to use the EV or may need to use fast charging 2 days a month. Simply increasing the battery capacity is not sufficient because the larger the EV’s battery the bigger and heavier the vehicle and the longer the charging time needed. Though it is necessary to improve the charging ability at home, it might be a good policy that we think the use of other transportation rather than making an EV perfect so as to match the long-range travel needs one or two days a month.