A team from Stellenbosch University which successfully converted a minibus taxi to an electric vehicle, believes there is potential for electric vehicle manufacturers in South Africa to open plants to produce electric vehicles locally.
Professor Thinus Booysen, from the department of Industrial Engineering at Stellenbosch University, said the recently completed prototype electric taxi, which is currently being tested for road safety, will be used to prove the concept and for testing.
SU joined forces with the company Rham Equipment to retrofit a minibus with electric propulsion, making it the first electric taxi of its kind in the country.
The South African National Energy Development Institute (SANEDI) provided funding for the retrofit, and Transport Services at SU donated a minibuse from its fleet.
Dr Neville Smith, project manager at SANEDI, said the novel approach to retrofitting normal combustion engines with EV engines will contribute extensively to achieving the country’s climate change targets, saying the first retrofitted minibus is just the beginning.
“More than 70% of the trips in South Africa are by minibus in the informal sector, which is why we are hoping to encourage the retrofitting of some of the 250 000 minibuses in the country with electric propulsion. These will be cheaper and much more environmentally friendly than new electric vehicles.
“With this venture, we want to help build the skills needed to manufacture electric vehicles locally and also create awareness about how much we could save with electric taxis.”
Kevin Reynders,CEO of Rham Equipment, said the collaboration with SU allowed the company to “plough back” into engineering students’ development and to contribute to sustainable mobility in South Africa.
One of Booysen’s team members, Stephan Lacock, who is doing his master’s degree in electronic engineering at SU and funded by Golden Arrow, helped designed the retrofitted minibus with partners at Rham Equipment.
Lacock said a standout feature of the retrofitted minibus is its advanced regeneration system which harnesses energy generated during deceleration and downhill driving, enhancing the vehicle’s energy efficiency and overall range.
“As a result, the minibus is now equipped to travel an estimated range of approximately 120 km, with a maximum speed of 120 km/h. It has an electric motor power of 90 kW and a battery capacity of 53.76 kWh. This ensures that it meets all load and driving requirements comparable to those of traditional internal combustion engine minibuses.
“Thanks to the inclusion of a 20 kW charger, the minibus can be efficiently charged in just over two hours.”
Lacock stressed that this is just the initial model, and that future advancements in technology will likely lead to more improvements in charging times, longer ranges by increasing the battery capacity, and overall performance.
PhD student and team member Johan Giliomee says the expected charging times that result from the way minibus taxis operate is a concern because of the additional load the simultaneous charging will put on the grid.
“Research results show that electrifying all minibus taxis in South Africa could add a load of 5% of what the grid can currently deliver.
Giliomee said minibus taxis could be supplied with electricity through the installation of solar panels and battery energy storage systems at taxi ranks. Hydrogen could also be used as an alternative electricity source or for interim energy storage.
“The vast majority of taxis are stationary between the early morning and afternoon peaks, making it an ideal opportunity for charging from solar panels. This also means a single charge would only need to supply sufficient energy for half the day, significantly reducing the required battery capacity as opposed to being scaled to support a full day’s operations. Further ideal charging opportunities are seen overnight when the national electricity demand is at its lowest.”
“We must think anew about how we buy a car; it must be sold as part of a mobility package, that is, the car, solar panels and a large battery as a system, rather than just an electric car that will mess up and be restricted by our grid.”
Booysen says in the next phase of the project they will collaborate with Rham and Golden Arrow Bus Service to retrofit one of the company’s buses.