South Africa has the highest emission intensity in the G20 group of industrialised and developing countries. This threatens its commitment to help slow global warming. This disproportionate contribution is driven by the country’s coal-dependent national electricity utility, Eskom.
In generating power, its plants release 512 billion kg of carbon dioxide into the atmosphere annually. The country’s road transport sector also contributes to the problem: it was responsible for 13% of the total share of energy related carbon emissions in 2018.
To reach its targets, South Africa must reduce emissions by 32% in the next 10 years alone. But Eskom is also the engine of the economy and struggles to meet current demand, with frequent rolling blackouts.
Internationally, electric vehicles have been considered a way to reduce emissions. In Europe, electric vehicles rose to 6.8% of passenger vehicle sales, with 167,000 sold in the first quarter of 2020 alone.
Currently, only around 1,000 of the vehicles on South Africa’s roads are electric, with substantial growth expected. But adopting them more widely isn’t the solution in itself because they would still depend on electricity generated from carbon-emitting coal power stations. They would also add to the strain on the electricity grid.
Fortunately, South Africa has abundant sunshine, which could help reduce the burden with solar charging. Unfortunately, electric vehicles tend to be charged at home and at night when it’s dark.
One way to make the best use of solar energy, without the need for expensive battery storage, is to charge vehicles during the day, using a solar photovoltaic carport at the workplace or large car parks.
Approximately a third of South Africa’s estimated 10 million households use a vehicle to drive to work each day, but the vehicle spends most of the day unused. Daytime charging from solar would consume energy directly and locally. It would avoid adding a load to the electricity system through adding electric vehicles.
In a recently published paper we explored what the impact would be of electric vehicles charging at home and at the workplace in South Africa. We examined the potential impact of electrification of the country’s vehicle fleet, and the concept that large employers, or car park owners, could provide solar photovoltaic carports as a service for employees, or parking clients, to charge their vehicles during working hours.
We ran simulations based on one, 1,000 and one million vehicles. Each simulation was run with scenarios of vehicles charging at home, vehicles charging at work and vehicles charging at both home and work. The work scenarios used solar photovoltaic carport charging, augmented as needed with the mostly coal-powered grid.
Our results showed that from a vehicle owner’s perspective it’s significantly more expensive to refuel a petrol vehicle than it is to charge an electric vehicle. We found that the cost can be more than halved if vehicle owners charge their vehicles at work.