*3.5. Charger Parameters*

The chargers are assumed to have a base cost of 5000 SEK per charger plus a size-dependent cost of 3000 SEK/kW. The low base cost means that the cost is almost only proportional to the total installed power of the chargers. The charger depreciation is calculated using an economic life of 10 years. This is similar to a normal contract period with a bus operator in Sweden. These cost levels are based on data from pilot projects and estimates how that cost will be reduced when building many new bus chargers at once for a contract with many bus lines. The cost has also been found to be consistent with the cost of high-power charges for electric cars, which are based on the same technology.

The assumed charger power *P*ChgEndstop is 300 kW for the end-stop-charged buses, and *P*ChgEndstopNight is 11 kW per bus for the night chargers for buses with 100 kWh battery and 22 kW for buses with 200 kWh battery.

There is also the factor of how much of the layover time which, on average over several trips, can be used for charging at end-stop chargers (*k*LayoverChargingFactor), and in this paper it is assumed to be 50%. Since the layover time is required to avoid delays, there are situations in which there will be some trips which are delayed so that there is no layover time to charge. However, the bus batteries are big enough so that one missed charge is not be a problem as long as the bus later during the day can compensate for that missed charging. That is a reason why it is assumed that some of the layover time may, on average, be used for charging.
