Impact of Electric Vehicle Charging on the Nairobi Aerial Distribution Network

Abstract

Kenya has a strong interest in electric vehicles (EVs), which are quickly being deployed in key cities such as Nairobi. The problem with the increasing number of EVs in the country is that they will lead to an increase in electrical power demand and excessive power losses. This paper seeks to analyze the impact of the large adoption of electric vehicles on the Nairobi aerial distribution network, with a focus on the Juja section. The methodology in this work assumes that 50% of the households in the study area own EVs. Two types of chargers to service the EVs are considered; Level 1 chargers and Level 2 chargers. Levels 1 chargers are installed at homes and are used to charge the EVs at night when the owners are back home, while Level 2 chargers are installed at commercial parking lots and are used to charge the EVs during the day when the EV owners are at work. A 24 hours Time Domain Analysis is performed using ETAP software considering two scenarios; the first being that all the EVs are charged at night from 9 pm to 6 am the next day using Level 1 chargers, and the second being that all the EVs are charged during the day from 10 am to 2 pm using Level 2 chargers. Simulation results show that charging all the EVs at night leads to an increase in the total daily active power loss in the study network from 0.57MW with no EVs to 190.36MW, while charging the EVs during the day using Level 2 chargers leads to an active power loss of 271.616MW. From this study, it is recommended that appropriate charging schemes must be put in place as the number of EVs keeps growing in Nairobi, and other parts of Kenya. Keywords—Electric vehicles, Charging stations, Nairobi, Power losses