Measuring the efficiency of electric buses

With the rapid increase in electric buses around the globe, performance data is starting to emerge. Many municipalities are also conducting their own bus trials to work out how particular buses will perform on their routes. This is giving decision makers more clarity on stated, versus actual energy efficiency (kWh/km) of electric buses. Factors such as ambient conditions, topography and bus characteristics have significant effects on the real performance of an electric bus.

Efficiency plays a key part in sizing a depot’s charging infrastructure, electrical upgrades and potential upstream infrastructure costs. It affects how long buses need to charge for, the coincidence of peak demand from multiple chargers and ability of buses to meet their charging needs in line with their schedule.

Average efficiency vs. dynamic modelling

An average efficiency (kWh/km), using data manufacturer’s stated numbers, data from another region, or even a route serviced from the same depot can lead to significantly under or over estimated energy consumption.

We compare using an average efficiency versus a dynamic model for two typical metropolitan routes  below.

Route A

Average from Manufacturer’s Data: 1.17kWh/km

BetterFleet Dynamic Model: 1.48kWh/km

Difference: 26%

Route B

Average from Manufacturer’s Data: 1.17kWh/km

BetterFleet Dynamic Model: 1.65kWh/km

Difference: 41%

This difference can lead to understated battery charging requirements leading to undersized charging infrastructure. Even if infrastructure is sized with margins for error, long-term operating costs from energy purchases will be significantly underestimated.

BetterFleet

Evenergi’s modelling software  BetterFleet™  can model individual routes from your depot, using actual topography and travel data. This means we can significantly de-risk your investment decisions when it comes to electrifying your bus fleet.

Find out more about how Evenergi can help here.