Impact of replacing ICE bus fleet with electric bus fleet in Africa: A lifetime assessment

Highlights

• Lifetime cost of ICE bus fleet is higher than Electric bus fleet by at least 38% in Africa.

• Lifetime cost of ICE bus fleet higher than hybrid-electric bus fleet by at least 27% in Africa.

• Carbon dioxide emission of ICE bus is 3.46 times that of a similar electric bus charged from the national grid in Africa.

• Carbon dioxide emission of ICE bus is 329 times a similar electric bus charged by solar electricity in Africa.

• ICE bus emission is 1.9 times HEV bus charged from national grid and 5.3 times HEV charged from solar electricity in Africa.

Abstract

It is globally agreed that electrification of the transportation fleet will be a significant step in reducing greenhouse gas emissions. This study assesses the impact of replacing internal combustion engine bus with electric bus fleets in African countries. The assessment includes the impact of solar charging of an electric bus fleet. Emission factors based on the energy mix in the various African countries were used to determine greenhouse gas emissions from electricity generation. Data from a standard public bus fleet was used as a comparison for the internal combustion engine (ICE) fleet. Lifetime costs favor operating an electric bus by 62% and hybrid-electric bus by 50% when charging is done from the national grid. Solar charging has the potential to further reduce lifetime costs by at least 19% and at most 47%. ICE bus emits 3.46 times the emissions of an electric bus. If charging is done by solar, then ICE bus emits 329 times more. Since there is a significant tariff reduction for fuel compared to electricity in African countries, a recommendation is made to reverse this to promote the use of electric vehicles. It is recommended that government fleet transition to electric vehicles.

Introduction

In Ghana and Morocco, above 40% of the energy emissions are attributed solely to the transportation sector [1]. Africa’s energy-related emission in 2018 was 1215 Mt CO₂ [2]. North African countries contributed 40% (490 Mt CO₂) of Africa’s emissions while South Africa alone emitted 34% (420 Mt CO₂). We have estimated that there are at least 55 million vehicles in Africa. Together, South Africa, Nigeria, Egypt, Algeria, and Morocco account for 70%. In providing solution to transport challenges, one of the key elements is zero-pollution modes of public transport that will reduce environmental impacts. Internal combustion engine (ICE) buses generate 25% of the black carbon emission in the transportation sector in the world [3]. This is expected to increase to 50% by 2030 resulting in extra 26,000 tons of black carbon and causing an increase in premature death [3]. Sustainable city transport initiatives in Africa should be geared towards electric buses to reduce its effect on climate change. Europe’s forecast estimate that by 2025, 32% of buses to be purchased in Europe will be electric [4]. Already there are many commercially available electric buses as shown in Table 1. On 20 February 2020 it was announced that BYD Europe is to supply 29 pure electric buses namely the BYD Enviro400EV to London’s bus services route 94 [5]. The BYD k9M buses are part of the battery electric vehicles deployed at many international airports such as Atlanta and Glasgow airports [6,7]. For these reasons BYD C9 electric bus was chosen for our studies. Comparisons were made with State Transport Corporation ICE buses in Ghana made of Scania Marcopolo buses. For comparison with a hybrid-electric bus, Volvo 7900 Hybrid was chosen for this work. A rare insight has been given into the energy emissions, energy situation, price regime, and state of electric vehicle penetration on the continent. Also considering that a number of governmental bodies in Africa recommend the carbon dioxide mitigation benefits and lifecycle cost benefits of electric buses, this work will be of great benefit to them. Many African countries are either considering or are at pilot stages of introducing electric buses but are yet to consider the lifetime cost and possible emissions savings [4]. This research contributes in helping to answer these questions.