*2.5. Cost of Conventional Combustion Engine Buses*

The TCO model is mainly developed to analyse electric buses, but it can also analyse conventional buses since they are less complex. As there is no need for conventional buses to be fuelled during the day, they only need to meet the requirement of driving their designated amount and the minimum number of trips to and from the depot. They need no extra time to charge or extra time to drive to and from the depot, as may be needed by electric buses. The TCO for them is calculated using the same formula, but with slightly different cost parameters, as shown in Table 1. Rather than calculating the volume of fuel consumed, the cost of the conventional buses fuel is calculated from required traction energy, the fuel cost per litre and the average fuel efficiency of the powertrain.


**Table 1.** The cost parameters for buses powered by HVO, biomethane, and electricity when charging at the end stop, and at the end stop only during off-peak time. The values are relevant for Sweden 2019, and based on results from pilot projects.
