Quote:
Originally Posted by someone123
Another awkward thing right now is that there's a transition to battery electric vehicles underway. So would anybody bother installing new overhead wire systems now? And is there ultimately any advantage to a streetcar over an electric bus? Self-driving will have a similar effect in lowering the advantage to going with bigger vehicles or fully dedicated ROWs that could be automated going back to the 80's.
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For sure, it's definitely a hard decision. However, I will say that while I think electric buses are great and a clear improvement which I support, for high frequency services wired vehicles still have advantages.
- Battery buses are extremely heavy which has implications for road maintenance and energy usage. Battery buses are also not as efficient as wired since not only are they heavier, but there is energy loss when charging and discharging. Not a big deal with small devices and for vehicles that can't really be wired such as cars, but something to consider in this case. Since 20-30% of the energy is lost during the charge/discharge cycle, let's look at Protera's ZX5 model which comes in 220, 440, and 660 kW-hr versions. For the 440 version, 440 kW-hr of electricity is equal to the power used by forty-four hundred 100 watt microwave ovens running for an hour. If 25% is lost, the lost energy is enough to power 1467 of the microwaves for an hour. For each bus, for each charge cycle.

Still more efficient than ICE vehicles, but damn. Plus, rail vehicles tend to last longer and require less maintenance than road vehicles.
- Battery buses also are at a disadvantage in the winter since heating pulls a lot of power, particularly in a vehicle with constantly opening doors. As a result, battery buses in Canada such as the fleet in Toronto have fossil-fuel powered heaters meaning that for much of the year, buses still need to be "fueled".
- The fact that battery technology is progressing so rapidly also makes it awkward to know when to invest millions in battery vehicles (which are twice the cost of fossil fuel vehicles) given that any vehicle one buys today may be soon obsolete. So there is possible "opportunity cost" issues with both. Yet there is also opportunity cost with any delays, not only due to climate change, but also the longer you wait, the longer you go without the reduce fuel and maintenance cost of electrification.
- Most vehicle batteries still aren't recyclable and with such a huge level of embedded energy are still not as environmentally friendly as wired vehicles (on a frequent route) despite being better than fossil fuel vehicles over their lifecycle.
Cities should really be investing in battery buses regardless. If they're displaced from core routes by overhead power, they can still be used elsewhere and the benefits in the core will still exist.