What is required for the use of E-buses in the city of Kigali to reduce air pollution
As Rwanda continues to look for solutions to the e-mobility, an E-bus solution may be far as there is a lot to be considered by the Government and investors.
Recently, when Rwanda was showcasing the E-mobility solutions, a research report on E-buses in Kigali was also released.
The report, which was published by experts, looked at roads that could be used by E-bus, including long distance roads, and found that the problem of charging batteries is still difficult.
The report said that at least one e-bus could take an hour and a half to be charged.
The report entitled “Quick Scan Charging Infrastructure for Kigali e-buses” highlights that a high-level qualitative analysis (quick scan) has evaluated 3 e-bus charging variants on three existing KBS bus lines in Kigali, and their impact on costs, realisation time, grid capacity and operation. “
This includes the longest line within city zone 1 with an average distance of 277 km per day.
Based on the insights gathered, general conclusions were drawn for the electrification of buses in Kigali.
International best practices show that ‘Depot charging’ is often the preferred variant from an operational, financial and grid perspective.
For the case of Kigali however, current e-bus technology with depot charging (Variant A) is not adequate to electrify the 3 lines reviewed
This is because the range of available e-buses is limited to ±230 km, due to the relatively high estimated energy use in Kigali’s climate and topography.
Provided that there needs to be an operational minimum (15%) to the battery energy level (for exceptions and outliers in daily distance), and to account for future battery degradation (20%), the actual daily distance that can be covered is ±150 km.
According to the report “This means depot charging is not feasible for the currently analysed 3 lines, without changes to the bus schedule. It would only be feasible if, during the day, the bus would charge at the depot for approx. 1.5 hour.”
The report also revealed that 15 companies could supply e-buses to Rwanda, largely Chinese. These suppliers focus on plug and/or pantograph charging.
There are some recommendations made for the E-bus piloting in Kigali City among them are
- To formulate an e-bus pilot plan and projects.
- To start with electrification of the shortest lines (< 150 km per day), through implementation of depot charging. If possible, to look for lines that use a depot that could be used to electrify other lines as well.
- To test the technology and implications in operation for technical personnel, bus drivers, and organisation, and specifically to validate real-world e-bus energy drivers, and organisation, and specifically to validate real-world e-bus energy consumption.
- To gather data through on-board telemetry on existing buses (to measure daily distance, speed, stop times, elevation, location, etc.) as input for extended electrification feasibility analysis.
- To investigate the option with the bus supplier to include solar panels on the roof of the bus (to run the internal systems such as lighting, air-conditioning, etc.), thereby extending the operational range of the electric buses among others