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Interdependence of electrical energy supply and mobility in the electrification of the sub-Saharan paratransit system
Thesis (PhD)--Stellenbosch University, 2025.
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Stellenbosch : Stellenbosch University
2026
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| access_status_str | Open Access |
| author | Pretorius, Brendan George |
| author2 | Booysen, M. J. (Thinus) |
| author_browse | Booysen, M. J. (Thinus) Pretorius, Brendan George |
| author_facet | Booysen, M. J. (Thinus) Pretorius, Brendan George |
| author_sort | Pretorius, Brendan George |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhD)--Stellenbosch University, 2025. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/134781 |
| institution | Stellenbosch University (South Africa) |
| last_indexed | 2026-06-10T12:40:54.381Z |
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| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2026 |
| publishDateRange | 2026 |
| publishDateSort | 2026 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
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| spelling | oai:scholar.sun.ac.za:10019.1/134781 Interdependence of electrical energy supply and mobility in the electrification of the sub-Saharan paratransit system Pretorius, Brendan George Booysen, M. J. (Thinus) Strauss, J. M. (Johann) Stellenbosch University. Faculty of Engineering. Dept. of Electrical & Electronic Engineering. Electric vehicles -- Africa, Sub-Saharan Local transit -- Africa, Sub-Saharan Electrification -- Africa, Sub-Saharan Battery charging stations (Electric vehicles) -- Africa, Sub-Saharan Thesis (PhD)--Stellenbosch University, 2025. Pretorius, B. G. 2025. Interdependence of electrical energy supply and mobility in the electrification of the sub-Saharan paratransit system. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/04e43462-1a46-4751-b464-1e7d129146cd ENGLISH ABSTRACT: The global north is increasingly shifting towards the use of electric vehicles as another means of clean transportion. Electric mobility provide substantial benefits in terms of lower emissions, lower operating cost and less maintenance to name a few. Sub-Saharan Africa has taken heed of these changes in the global north, with various policies and frameworks introduced to help this transition. The paratransit industry, which is a decentralised, informal and unscheduled mode of transport, is the main mode of transport in the region. It constitutes various modes that include two-wheelers (boda-boda) and three-wheelers (tuk-tuk). But the predominant mode is the minibus taxi (matatu) – the focus of this work. This industry forms a vital part in the community as it acts as a source of livelihood for many individuals, and many rely on it as their main form of transport. The electrification of this industry could provide substantial benefits to the community and the environment, and could present a viable pathway toward sustainable and efficient transport in Africa. However, planning for this transition to an electric fleet of minibus taxis requires a comprehensive understanding of the various system components, and how they may be affected by a transition. For example, many countries in the region have fragile electricity networks and suffer from electrical energy scarcity. This is further complicated by paratransit’s unique, unscheduled, decentralised, and demand-driven nature. This transition to electric paratransit remains under-explored in scholarly literature. Many of the simulation tools in the global north do not account for the nuances seen in the paratransit industry To address this gap, this thesis presents a method by which to assess impact of transitioning on the electrical energy supply and mobility of this unwieldy mode of transport. Accordingly, the concepts of vehicle-day and fleet-day are introduced, which provides a framework for assessing the relationship between mobility and electricity demand. By analysing the vehicle-days, the viability rate (how many successful full day trips a vehicle was able to finish) can be used to assess the mobility implications of electrification. By analysing the fleet-day, the expected grid power required for the viable vehicles can be determined. These concepts were then applied to a specific use case scenario for the town of Stellenbosch, near Cape Town, in South Africa, where 17 minibus taxis were tracked for a month. Various charging locations were analysed, including charging only at the depots, charging only at the home, or charging at both. The assessment also considered different number of charging points and different charging rates. Having depot only charging at 7.2 kW, resulted in an 11% viability rate. This means that for a fleet of minibus taxis, only 11% of the vehicles and their trips would be completed or be able to be converted to electric vehicles. However, if the same charging rate is installed at home only, the viability rate increases to 45%, substantially better than the depot only scenario. With both depot and home chargers installed, all at 7.2 kW, the viability rate increases to 68%. Further results showed that the highest possible viability rate that can be achieved for the minibus taxis was 86% - achieved with 50 kW depot chargers and 7.2 kW home chargers. Although this number is high, it is still not close to the desirable 100% viability rate deemed necessary for a seemless electric transition. These results indicate that the mobility patterns of the vehicles would need to change to obtain higher viability rates. Another key insight seen by these results, is that it rather makes sense to install home chargers for the vehicles than have chargers installed at the depot. However, these are not the only considerations. The first key consideration is mobility. At the 7.2 kW depot only charging scenario, vehicles could only travel up to 120km in a given day. However, by having home only, this number is increased by 60 km, to 180km travel distance in a day. Similar to the viability rate, having both depot and home chargers, increases the distance these vehicles can travel, to 210 km. For the best case scenario of 50 kW depot charging and 7.2 kW home charging, the maximum distance a vehicle could travel was increased to 280 km. Again, home charging was shown to increase this distance in all scenarios, further bolstering home charging incorporation in the electric transition. The second key consideration is electricity grid impact. Demand peaks were found to be in the morning at the depot between 08h00 and 10h00, and an evening peak between the hours 19h00 and 21h00. Fast charging was shown to substantially increase the peaks, but the introduction of home charging significantly reduced it. It was further shown that the current South African grid can not handle the introduction of large scale electric minibus taxis. Even in the best case scenario, the fast chargers of 50 kW were found to worsen the grid situation further. A possible to solution to the low viability rate was then presented in the form of restructuring the mobility to a more scheduled nature. This solution was found to reduce the number of vehicles required to perform the same amount of trips, as well as reduce the number of chargers required to service the vehicles. In this solution, the concept of a mixed-fleet (both internal combustion engines and electric vehicles in operation) was found to be the optimal solution. The grid power for the scheduled scenario was also found to have a lower peak, but spread across the day more evenly. Lastly, in any electric transition, the transition should be equitable for all, or “just” for all; even more so for the mainstay of transport in sub-Saharan Africa, the paratransit industry. The “justness” of an electric transition was investigated in this thesis by characterising the vehicle-days according to their home location. Two groups were identified using this method. Group A was found to have a higher electrification viability rate of 82% compared to Group B’s 32%. This was a consequence of Group A performing more inter-city trips, and Group B performing more intra-city trips. Thus, the transition to electric would not be beneficial to all, and appropriate policies would need to be put in place to ensure a just transition for all. This thesis provided a framework for analysing the electrification of the paratransit industry, and applied it to a case scenario. Valuable results were generated that will inform policy makers, and allow others to perform investigations for their own regions. AFRIKAANSE OPSOMMING: Die globale noorde beweeg toenemend na die gebruik van elektriese voertuie as ’n alternatiewe vorm van skoon vervoer. Elektriese mobiliteit bied aansienlike voordele in terme van laer emissies, laer bedryfskoste en minder instandhouding, om maar ’n paar te noem. Sub-Sahara Afrika het kennis geneem van hierdie veranderinge in die globale noorde, met verskeie beleide en raamwerke wat ingestel is om hierdie oorgang te ondersteun. Die paratransportbedryf, wat ’n gedesentraliseerde, informele en ongeskeduleerde vervoermodus is, is die belangrikste vervoermiddel in die streek. Dit bestaan uit verskeie vervoermiddele, insluitend tweewielers (boda-boda) en driewielers (tuk-tuk). Die oorheersende vervoermiddel is egter die minibus-taxi (matatu) – die fokus van hierdie werk. Hierdie bedryf speel ’n deurslaggewende rol in die gemeenskap aangesien dit ’n lewensbestaan vir baie individue bied en vir baie mense die primêre vervoermiddel is. Die elektrifisering van hierdie bedryf kan aansienlike voordele vir die gemeenskap en die omgewing inhou en kan ’n lewensvatbare pad na volhoubare en doeltreffende vervoer in Afrika bied. Die beplanning vir hierdie oorgang na ’n elektriese vloot minibus-taxi’s vereis egter ’n omvattende begrip van die verskeie stelsels en hoe hulle deur die oorgang beïnvloed kan word. Byvoorbeeld, baie lande in die streek het brose elektrisiteitsnetwerke en ly aan elektrisiteitsgebrek. Dit word verder bemoeilik deur paratransport se unieke, ongeskeduleerde, gedesentraliseerde en vraaggedrewe aard. Hierdie oorgang na elektriese paratransport bly steeds onderondersoek in akademiese literatuur. Baie van die simulasie-instrumente in die globale noorde hou nie rekening met die nuanses van die paratransportbedryf nie. Om hierdie gaping aan te spreek, stel hierdie tesis ’n metode voor om die impak van elektrifisering op die elektrisiteitsvoorsiening en mobiliteit van hierdie onvoorspelbare vervoerstelsel te beoordeel. Dienooreenkomstig word die konsepte van “voertuig-dag” en “vloot-dag” bekendgestel, wat ’n raamwerk bied om die verhouding tussen mobiliteit en elektrisiteitsbehoefte te ontleed. Deur die voertuigdae te analiseer, kan die lewensvatbaarheidskoers (hoeveel voertuie daarin geslaag het om ’n volle dag se ritte te voltooi) gebruik word om die mobiliteitsimplikasies van elektrifisering te evalueer. Deur die vlootdae te ontleed, kan die verwagte netwerkkragbehoefte vir die lewensvatbare voertuie bepaal word. Hierdie konsepte is toegepas op ’n spesifieke gevallestudie vir die dorp Stellenbosch, naby Kaapstad, Suid-Afrika, waar 17 minibus-taxi’s vir ’n maand dopgehou is. Verskeie laailokasies is geanaliseer, insluitend laai slegs by depots, slegs by die huis, of beide. Die assessering het ook verskillende getalle laaipunte en laaispoed in ag geneem. Laai slegs by die depot teen 7.2 kW het gelei tot ’n lewensvatbaarheidskoers van 11%. Dit beteken dat slegs 11% van die voertuie en hul ritte suksesvol na elektriese voertuie kon omskakel. Indien dieselfde laaispoed slegs by die huis beskikbaar is, verhoog die lewensvatbaarheid tot 45% – aansienlik beter as die depot-scenario. Met beide depot- en tuislaai teen 7.2 kW, verhoog die lewensvatbaarheid tot 68%. Verdere resultate het gewys dat die hoogste moontlike lewensvatbaarheid vir die minibus-taxi’s 86% was – behaal met 50 kW-depotlaaiers en 7.2 kW tuislaaiers. Hoewel hierdie getal hoog is, is dit steeds nie naby aan die gewenste 100% lewensvatbaarheid vir ’n naatlose elektriese oorgang nie. Hierdie resultate dui aan dat die mobiliteitspatrone van voertuie sal moet verander om hoër lewensvatbaarheidskoerse te bereik. Nog ’n belangrike insig is dat dit meer sin maak om tuislaaiers te installeer eerder as om depotlaaiers te gebruik. Dit is egter nie die enigste oorwegings nie. Die eerste sleuteloorweging is mobiliteit. By die 7.2 kW depot-scenario kon voertuie slegs tot 120km per dag ry. Met slegs tuislaai is hierdie afstand met 60km verhoog tot 180km per dag. Met beide depot- en tuislaaiers kon voertuie tot 210km per dag reis. In die beste scenario van 50 kW-depotlaai en 7.2 kW-tuislaai, het die maksimum afstand wat ’n voertuig kon aflê, tot 280km gestyg. Tuislaai is dus in alle scenario’s belangrik om mobiliteit te verbeter. Die tweede sleuteloorweging is die impak op die elektrisiteitsnetwerk. Vraagspitse is waargeneem in die oggend tussen 08h00 en 10h00 by die depot, en in die aand tussen 19h00 en 21h00. Vinnige laai het die spitsvraag aansienlik verhoog, maar die byvoeging van tuislaai het dit verminder. Daar is verder getoon dat die huidige Suid-Afrikaanse kragnetwerk nie die grootskaalse bekendstelling van elektriese minibus-taxi’s kan ondersteun nie. Selfs in die beste scenario het 50 kW-vinnige laaiers die netwerksituasie verder verswak. ’n Moontlike oplossing vir die lae lewensvatbaarheidskoers is om mobiliteit te herstruktureer na ’n meer geskeduleerde model. Hierdie benadering verminder die aantal voertuie wat nodig is om dieselfde aantal ritte uit te voer en verminder ook die aantal laaistasies. ’n Gemengde vloot (bestaande uit beide binnebrandenjins en elektriese voertuie) is gevind as die mees doeltreffende oplossing. Hierdie oplossing het ook ’n laer en meer egalige piekkragbehoefte in die netwerk getoon. Laastens, in enige elektriese oorgang, moet die oorgang regverdig wees vir almal – veral vir die paratransportbedryf, wat ’n pilaar van vervoer in Sub-Sahara Afrika is. Die regverdigheid van die oorgang is ondersoek deur voertuigdae te klassifiseer volgens hul tuisligging. Twee groepe is geïdentifiseer. Groep A het ’n hoër elektrifiseringslewensvatbaarheid van 82% getoon, vergeleke met Groep B se 32%. Dit was omdat Groep A meer inter-stadsritte uitgevoer het, terwyl Groep B hoofsaaklik binne die stad vervoer het. Dus sal die oorgang na elektriese voertuie nie vir almal voordelig wees nie, en gepaste beleid moet ingestel word om ’n regverdige oorgang te verseker. Hierdie tesis het ’n raamwerk verskaf om die elektrifisering van die paratransportbedryf te analiseer en het dit op ’n gevallestudie toegepas. Waardebare resultate is gegenereer wat beleidmakers sal inlig en ander sal help om soortgelyke ondersoeke in hul eie streke uit te voer. Doctoral 2026-01-07T13:15:55Z 2026-01-07T13:15:55Z 2025-12 Thesis https://scholar.sun.ac.za/handle/10019.1/134781 Stellenbosch University xv, 133 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Electric vehicles -- Africa, Sub-Saharan Local transit -- Africa, Sub-Saharan Electrification -- Africa, Sub-Saharan Battery charging stations (Electric vehicles) -- Africa, Sub-Saharan Pretorius, Brendan George Interdependence of electrical energy supply and mobility in the electrification of the sub-Saharan paratransit system |
| title | Interdependence of electrical energy supply and mobility in the electrification of the sub-Saharan paratransit system |
| title_full | Interdependence of electrical energy supply and mobility in the electrification of the sub-Saharan paratransit system |
| title_fullStr | Interdependence of electrical energy supply and mobility in the electrification of the sub-Saharan paratransit system |
| title_full_unstemmed | Interdependence of electrical energy supply and mobility in the electrification of the sub-Saharan paratransit system |
| title_short | Interdependence of electrical energy supply and mobility in the electrification of the sub-Saharan paratransit system |
| title_sort | interdependence of electrical energy supply and mobility in the electrification of the sub saharan paratransit system |
| topic | Electric vehicles -- Africa, Sub-Saharan Local transit -- Africa, Sub-Saharan Electrification -- Africa, Sub-Saharan Battery charging stations (Electric vehicles) -- Africa, Sub-Saharan |
| url | https://scholar.sun.ac.za/handle/10019.1/134781 |
| work_keys_str_mv | AT pretoriusbrendangeorge interdependenceofelectricalenergysupplyandmobilityintheelectrificationofthesubsaharanparatransitsystem |