LTLFTcomposite wrote:More EV buses for Park City:
https://www.parkcity.org/Home/Component ... ews/29717/
Interesting they would attempt that for the PC-SLC route. I wonder what the specs would look like for a model to handle the climbs (and downgrades) over that distance.
Looking at the
timetable for that route, it appears it is designed to be handled by two buses, both garaged in Salt Lake City. Each bus makes four round trips daily each of which is comprised of 2 55- to 65-minute one-way trips with six stops each and a 10-minute stop at each terminus. The one-way distance traveled is 26 miles for a total of 208 miles each day. Total time on the route each day is 8.5 hours (excluding the 5.5 hours of breaks in SLC in the middle of the day).
If the vehicle rests and charges during the entire 5.5-hours of breaks each day, this route can be easily serviced using
Proterra Catalyst E2 Max buses. That would only require the buses travel 104 miles over a 4.25-hour period before being fully recharged. That would only require a minimum efficiency of 5.8 kWh/mile or an average draw of 70 kW or less while enroute (assuming 600 kWh used each half-day).
The worst-case scenario is for a
660-kWh Proterra bus that is only charged at night and serves other routes in SLC for the other five hours of the day. In that case, the total driving range for the day would approach 300 miles. If we assume no charging during the entire 14-hour day, the minimum efficiency required would be about 2 kWh/mile (assumes 600 kWh used). That seems extremely unlikely for a vehicle which achieves an efficiency of only 1.89 kWh/mile without HVAC.
Another idea is that the bus travels the 300 miles but is charged at each of the terminus locations for a total of about 120 minutes per day. According to
Proterra's specifications, their E2 buses can charge at 325 kW using the overhead charger. This approach could add another 650 kWh of charge through the course of the day. Adding that to the 600 kWh that was available at the start of the day, that comes to a total of 1250 kWh available, which would allow the completion of this route structure even if average efficiency dropped to 4.2 kWh/mile. This is equivalent to an average draw of 89 kW over the course of the entire 14-hour day.
In any case, use of the Proterra buses on this route will
significantly reduce energy consumption as well as
overall cost when compared with the use of a diesel bus.
These buses
when equipped with the Duopower drivetrain can climb a 23% grade, so there is no issue with the slopes involved.
My conclusion is that this route can be handled by buses which are currently available from Proterra. Operational considerations will determine what features the buses need in order to meet the requirements.
