The Energy Demand And Fulfilment Thereof For Electric Minibus Taxis In Sub-Saharan Africa
| dc.contributor.advisor | Booysen, M. J. | en_ZA |
| dc.contributor.author | Giliomee, Johannes Human | en_ZA |
| dc.contributor.other | Stellenbosch University. Faculty of Engineering. Dept. of Electrical & Electronic Engineering. | en_ZA |
| dc.date.accessioned | 2025-02-04T13:36:19Z | |
| dc.date.available | 2025-02-04T13:36:19Z | |
| dc.date.issued | 2024-12 | |
| dc.description.abstract | The need to electrify the paratransit industry in sub-Saharan Africa (SSA) is urgent, with emissions from transport being detriment to both planet- and human-health. The dominant vehicle mode in this industry is the minibus taxi, with millions operating every day across the continent. Targeting the electrification of this vehicle will thus have impactful consequences. However, considering the relatively unknown nature of their operations, the limited range of electric vehicles, and electricity scarcity in the region, the electrification of this industry requires comprehensive energy analysis. This includes both the energy usage of an electric minibus taxi, and how this energy can be supplied. This thesis provides an in-depth analysis on the energy efficiency and requirements of an electric minibus taxi, the expected electrical supply requirements for charging, and how sustainable long-distance trips can be achieved. It is found that the energy efficiency is heavily dependent on the driving scenario. Urban, inter-city, uphill, and downhill driving scenarios are analysed, with results ranging from 0.29 - 0.51 kWh/km. On average, an energy efficiency of 0.39 kWh/km is found using high-frequency mobility data as input. It is also found that the sampling frequency of mobility data used as input to energy models has a substantial effect on energy analysis, as a low sampling frequency (minutely) fails to capture full micro-level movements. The daily energy requirement of an electric minibus taxi is reliant on the operation of the vehicle, such as the total distance travelled during the day, and whether the vehicle operates in an urban or inter-city scenario. As such, average energy requirements range from 56 - 215 kWh/day for taxis travelling 81 - 296 km/day. Furthermore, high-frequency mobility data is used to improve an existing micro-mobility simulation tool. Various shortcomings in the simulation are found, such as a misrepresentation of the physical road infrastructure, inaccurate waypoint progression, and an unrepresentative driving style. To assess the grid-impact, a software tool is developed to simulate charging of a minibus taxi fleet. For the applied use case of minibus taxis operating in Johannesburg, South Africa, a peak grid-load of 12 kW/taxi, and grid-drawn energy of 87.4 kWh/taxi/day are found. As minibus taxis are predominantly used by daily commuters, these charging peaks are seen multiple times per day (specifically during the morning and evening). To reduce the electrical supply requirements, a solar and external battery system is added to the simulation. For an external battery capacity equivalent to 50% of the electric minibus taxi’s capacity and solar system sizing of 9.45 kWpk/taxi, the average peak power draw is reduced by 66%, while total grid-drawn energy reduced by 58%. To enable sustainable long-distance paratransit, an operational plan using swappable, solar-charged battery bank trailers is developed. Compared to an electric minibus taxi, this operational plan increases vehicle range by 120%, reduces average recharging downtime by 74%, and reduces CO2 emissions by 80%. Although it is clear that there are many obstacles to overcome in the pursuit of electrifying paratransit in SSA, the methodologies and results presented in this thesis lay the foundation for future research and electric minibus taxi implementation in SSA. | en_ZA |
| dc.description.version | Doctoral | en_ZA |
| dc.format.extent | 157 pages : ill. | |
| dc.identifier.uri | https://scholar.sun.ac.za/handle/10019.1/131665 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | Stellenbosch University | en_ZA |
| dc.rights.holder | Stellenbosch University | en_ZA |
| dc.title | The Energy Demand And Fulfilment Thereof For Electric Minibus Taxis In Sub-Saharan Africa | en_ZA |
| dc.type | Thesis | en_ZA |