There is a focused push for the use of green and sustainable forms of energy in all verticals. Be it industry, transport, recreation, green and sustainable energy is top of mind to keep the global carbon footprint at bay. A carbon footprint that is tied to the recent extreme weather phenomena that have been plaguing parts of the planet, especially in the last decade. Looking at the mobility sector, electrification is the direction the industry is moving towards. In this report, we will observe whether or not electric buses in Africa are feasible.
The present situation
Africa’s public transport fleet is comprised predominantly of diesel-powered buses and minivans with supporting infrastructure for these types of vehicles. These same vehicles are used for innercity and intercity commutes. Africa has the third-highest concentration of atmospheric CO2 behind the Mediterranean and Southeast Asia at 97.4 μg/m3, a figure that is higher than the global average of 82.3 μg/m3.
According to the United Nations Environmental Program (UNEP), 5 African countries have running Electic Bus programs which include Cote d’Ivoire, Senegal, Seychelles, South Africa, and Tanzania. That said, the electric bus fleet in the region still sits at less than 0.01% as per the 2020 report by International Council on Clean Transportation.
Technical Realities of Electric Buses vs. Diesel Buses
Range
Diesel engine technology has had a very long time to mature and as a result, diesel engines are now more efficient (can do more work with the same amount of fuel). A Golden Dragon 12m long diesel-powered bus with a 150L fuel tank has a range of 600 km. The time taken to refuel is up to 5 minutes from empty to full.
Whilst great strides have been made in battery electric vehicle technology, the range offered by an electric bus is still quite limited. A BYD 12m long battery electric bus has a maximum range of 280km, less than half of the equivalent diesel-powered bus. To charge the bus’ battery from empty to full takes up to 2 hours with a fast charger or up to 6 hours with a regular charger.
This then shows the greater versatility of diesel-powered buses. Their superior range and much faster refueling make them suited for both inner-city and intercity routes. Battery electric buses are capable of inner city routes as those fall well within the typical round trip distances associated with such trips.
Electric buses could have better range with more energy storage (bigger battery packs) however this will increase the overall weight of the buses and the space occupied by the batteries will consume available space for luggage and/or passengers.
Running costs of electric buses (and vehicles in general)
Electric vehicles including electric buses have far fewer moving parts. This makes their construction a lot simpler than the equivalent Internal Combustion Engine (ICE) vehicle. The less complex a vehicle is, the less maintenance it requires, and the more affordable the service and maintenance are. With an ICE vehicle, there is service for the engine gearbox and other mechanical devices required by the ICE powertrain.
A battery-electric vehicle may only have the drive motor as the only moving part or an additional gearbox to the drive motor for either improving efficiency or speed. These are far fewer moving parts than those needed by an ICE vehicle and also translate to fewer serviceable parts.
According to a study done by the Global Green Growth Institute, over the service life of a bus (15 years) the cost of operations and maintenance is over 3 times higher with Diesel buses than with battery electric buses.
The maintenance cost analysis detailed later in the report, indicates 90% reduction in maintenance cost for electric buses, when both direct and indirect costs are captured for diesel buses undergoing repair and maintenance.
Source: Global Green Growth Institute
Operational efficiency of electric buses
It has been established that diesel buses are cheaper to acquire and have a more efficient workflow thanks to their superior range (fewer refueling intervals) and quick refuelling times as opposed to battery electric vehicles. This is due to the existence of infrastructure that supports diesel-powered buses. When looking at battery electric buses, the infrastructure is nowhere near as prevalent. For the purposes of efficiency in the transport sector there are a number of scenarios:
- Fit larger batteries to the bus to increase the range.
Doubling the battery capacity of electric buses could theoretically double the range of the buses to match their diesel-powered counterparts. This means fewer charging intervals within a day.
But increasing battery size comes with its own drawbacks. Charging times which were already long become even longer. A bigger battery consumes more space which reduces the luggage capacity and/or passenger carrying capacity of the bus. A heavier battery also needs a stronger frame to hold it which further adds to the weight of the bus. The more weight the bus has, the more power it needs to move which will affect its efficiency. - Install numerous charging points along the bus routes.
Charging points (plug-in or pentagraphs) can be set up at every bus stop. This way the battery on the bus can remain an optimal size and have short but more frequent charges as it is operating on top of the long charges that it will get at the beginning or end of their routes.
This is very infrastructure intensive and for it to be effective, it requires the in-route chargers to be fash chargers. The faster they are, the higher the state of charge of the battery in the duration of its trip and the less time it will require charging at the beginning or end of the route. However, fast chargers are very expensive to acquire which then would raise the cost of setting up the infrastructure for electric buses - Make the batteries swappable
With swappable batteries, a bus no longer needs to be parked and charged. There can be a booth where a bus’ depleted battery is removed and the bus is fitted with a full one in about the same time it takes for a diesel bus to be filled up with fuel. Given this scenario, it can be possible for the electric to match the performance of a diesel bus. It can even enable electric buses to make long intercity trips in a reasonable time.
The drawback with this concept is that battery standards are different for different bus manufacturers which may pose compatibility issues with the chosen battery station. Batteries are also very expensive and having a stockpile of them enough to keep the fleet running might be too expensive.
Here are some best practice implementations curated by UNEP e-Bus Market Feasibility in the city of Harare:
- DC Plug-In: Shenzhen, China
China has successfully electrified its e-Bus fleet of over 16,000 buses. e-Bus operators collaborated with charging infrastructure providers to establish charging facilities at depots and the bus routes maintaining a 1:3 charger to-bus ratio.
The typical charging time reported in case of overnight charging at the depot is around 2 hours. However, there are also charging stations installed en route, which are reported to charge the buses in approximately 40 minutes. - DC Pantograph: City of Geneva
City of Geneva employs DC pantograph-based technology for charging trolley e-buses (ABB, 2019). The e-Buses are charged at three different output power levels: 600 kW, 400 kW and 45 kW. The 600 kW ‘flash’ charging stations that provide a quick power boost in a short span of 15-20 seconds are reportedly the fastest in the world. The 400 kW and 45 kW charging stations charge the battery in 5 and 30 minutes respectively. - Inductive charging (Wireless): Gumi, South Korea
South Korea started e-Bus operation in 2014, where the fleet is charged via induction (Ahn, 2017).
The Korea Advanced Institute of Science and Technology (KAIST) developed the proprietary magnetic resonance technology used for charging e-Bus batteries.
Every On-Line Electric Vehicle (OLEV) e-Bus is equipped with a special receiver which can collect electric power wirelessly from the underground power supply while in motion or at the stationary condition.
It is reported to operate at an efficiency of 85%. - Battery swapping: Jeju Island South Korea
Jeju Island South Korea is a unique market for e-Buses where charging by conductive, inductive and battery swapping technologies has been employed. E-buses with battery swapping technology operate on Jeju Island (Park, 2016).
The e-Buses used in this project has 51 kWh battery bank which is mounted on the roof of the bus. The battery swapping stations located at the bus-stops have battery charging facilities and robotic systems for swapping.
At the swapping station, there are two automatic robotic systems to remove the depleted battery from the bus and attach a fully charged battery.
The swappable batteries used in this project weigh approximately 760 kg and has a special shock absorption design feature (Begins, 2019).
Infrastructure needed for electric buses
The biggest hurdle with electric mobility the world over and especially in Africa is the charging infrastructure. The general approach with charging infrastructure is it is set up by the electric vehicle company. This can be observed with Tesla in America, Europe, and Asia or BYD in Zimbabwe (CMED & NetOne fleet). It is a huge investment but a necessary one for electric vehicles to be usable.
In a study done by UNEP on the e-bus Market Feasibility in the city of Harare, Zimbabwe, it is estimated that the charging infrastructure for a fleet of 50 electric buses requires a capital investment of close to US$1 million. It is worth mentioning that this is just a one-time cost with the serviceable life of these chargers matching the serviceable life of the buses they charge (10 years)
There also lies the power demands of electric vehicle charging infrastructure. For the fleet of 50 buses, it is estimated that the power demand from the grid stands at 2.4MW for overnight charging at the ZUPCO willowvale depot and 3MW for opportunity charging at the Market Square bus terminus. The last time Zimbabwe Power Company (ZPC) posted generation statistics, it showed that Harare’s power station was producing 0MW. In such a scenario, the fleet will be drawing power from the national grid to facilitate charging.
The frequent load shedding experienced in Zimbabwe also means that for electric buses to be reliable, there will be a need for alternative power sources to charge the buses which is an additional investment in power projects like solar farms or battery banks that are charged by the grid when electricity is present and used to charge the buses during load shedding to maintain normal operations.
The economic opportunities
Electric mobility is still very much in its infancy making the investment opportunity quite big. The whole value chain is greatly underserved from the buses themselves to the charging infrastructure. The lifetime savings in fuel imports and maintenance are quite significant and will improve as the technology matures.
There is an opportunity in vehicle manufacture and assembly. Major parts associated with battery electric buses are quite modular and simple to assemble which can be done locally as opposed to importing finished buses. Investors can set up public charging infrastructure based on international best practices and earn revenue from them.
Using battery electric buses will also cut on the national diesel consumption. Diesel is an imported product that consumes foreign currency reserves. Consequently, public transport is one of the biggest consumers of diesel globally. Passenger transportation accounts for 50 to 60% of the energy consumption derived from transportation activities so some big savings in forex consumption are to be realized.
Policy
Issues of climate change have pushed for the use of greener forms of energy globally. As such, almost every country has put in measures to encourage the use of greener sources of energy and also append steep penalties for the use of dirty forms of energy.
In general, VAT and carbon tax are levied on ICE vehicles as well as their fuel whereas with electric vehicles, policy exempts or waivers a portion of taxes and carbon levies. Looking at Nepal, electric vehicles for public transport (40 seaters) will face a 1% customs duty fee and are exempted from VAT whilst ICE buses face a 5% customs duty fee and 13% VAT.
In Zimbabwe, VAT and customs duty for both ICE buses and electric buses are the same at 10% and 5% respectively. There is an exemption of income tax on electric buses which is 7.5% on ICE buses.
Key takeaways
- The capital requirements of an electric bus scheme are the biggest hindrance to them taking off in Africa.
- An electric bus is on average 3 times cheaper to purchase than the equivalent electric bus. So even with duty and VAT exemptions, it’s still more expensive than an ICE bus.
- A lack of independent investment in charging infrastructure leaves the full burden on the electric bus operator which then is not feasible.
- Factors such as slow charging times and limited range make them less desirable than their ICE equivalents.
- Over time, with a mature charging network, electric buses are over 3 times cheaper than ICE buses in operation and maintenance costs.
- More use of electric buses means a reduction in fuel imports and a reduction in forex spending.
- There are gains to be made in air quality in densely populated cities reducing the effect of pollution on the health of the inhabitants and overall reduction of greenhouse gases.
