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To Really Cut Emissions, We Need Electric Buses, Not Just Electric Cars
An anonymous reader writes: All the EV attention these days is going to Tesla and other sedan manufacturers, but this article makes the case that it's far more important to switch our buses over to electric power than our cars. "Last year, according to the American Public Transportation Association, buses hauled 5.36 billion passengers. While usage has fallen in recent years, thanks in part to the growth of light rail and subway systems, buses still account for more rides each year than heavy rail, light rail, and commuter rail combined—and for about half of all public transit trips." This, while managing around 4-5 miles per gallon of gas, and public buses usually average about 50,000 miles per year. The electric buses themselves are significantly more expensive, but the difference is made up dramatically lower fuel costs. And there will be difficulties: "The range—up to 30 miles—limits Proterra buses to certain routes, so it's hard for an agency to go all in. Drivers have to be trained to brake and accelerate differently, and to maneuver into the docking stations. And Doran Barnes of Foothill Transit notes that some of the cost advantage of using electricity instead of diesel can dissipate. Electric cars can be charged at night, when power prices are low. But buses have no choice but to recharge in the middle of the day, when utilities often impose higher peak usage rates."
Diesel engines are powerful but they pollute A LOT. And don't forget ships. That bunker fuel many of them burn is NASTY.
Pain is merely failure leaving the body
I know i'm old but there was a time when most buses ran off electricity using an overhead wire for power transfer. What's with wanting to go to battery power for this use. It's not like we could have forgotten this technology and with an update using today's technology we have to be able to make it better. Buses have defined routes so we can't argue that it limits flexibility...buses aren't cars, they don't have to be able to go down every road.
The biggest inefficiency with a (short-route) bus is stop-starting a heavy vehicle laden with people.
We have electric and hybrid buses in London, but using a Flywheel (first developed as a fuel-saving measure for F1 cars) to preserve kinetic energy has made the greatest difference to efficiency for London buses.
Shanghai has had some buses using these for several years. They recharge at some of the bus stops.
A bus will only get a few mpg, but carries a lot more people.
Sometimes it does. I see a lot of buses driving around 90+% empty.
I don't care if it's 90,000 hectares. That lake was not my doing.
If you are going to be limited to certain routes, why not electrify the routes and then save the weight of the batteries? Then you won't have to worry about recharge times either so you'll get more daily miles out of each bus too.
You might get the occasional free-rider but only on april 1st.
I see a lot of cars driving around 80% empty. To and from work, I must admit that one of them is mine.
Humans like cars, not buses.
And if you taxed larger or powerful cars heavily*, people would drive more fuel efficient cars. High gas taxes are doing that in some parts of Europe.
In the USA, at least, cars are a status/phallic symbol and thus are larger and/or more powerful than they need to be in a practical sense. There are times I wanted a more powerful car to compete with other more powerful cars during rush hour. But that's size escalation. If you lower the average then there is less need to compete with beefy cars.
Further, taxing beefy cars would encourage more to take public transportation. I know conservatives will balk, but taxes would help with three problems: traffic, pollution (and GW), and gas dependance. Four actually: gov't revenue to help pay down debt and other uses.
* Exemptions would be made for large families and legitimate business use.
Table-ized A.I.
The largest container ships have huge particulate emissions, but that's because there's no regulation on particulate emissions according to international law. It would be difficult to change that, because regulating ships requires an international agreement. That said, it should be done.
However, ships already have extremely low CO2 emissions per ton-mile. They are already extremely fuel-efficient. The largest ships have 1/15th the fuel usage and CO2 emissions per ton-mile as a tractor-trailer truck, and massively better than your car. If you drive one mile to the store to buy an article of clothing, you have emitted vastly more CO2 than was emitted by shipping it halfway around the globe by containership.
That will have almost no effect on your CO2 emissions.
We should have been working hard at improving nuclear power, and solving its problems, to the point that this would, by now, be a no-brainer. So those polluting diesels are another thing we can blame on the environmentalists that shut down nuclear power research in the '70s.
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San Francisco has had a fairly extensive trolleybus network since the 1930s. Although only 15 bus lines are trolleybuses, those are the most crowded bus lines, so a significant fraction of bus traffic there is electrified.
It appears that diesel buses cost $450,000, and battery-electric buses cost $825,000, and trolleybuses cost $1m each. Trolleybuses last at least twice as long as diesel buses. The overhead wires cost $2 million per mile and last almost indefinitely, it appears, because I have never seen maintenance being performed on any of them, in contrast to roads and stoplights which are being repaired constantly, and buses which are being replaced often enough.
San Francisco has 300 trolleybuses for 15 lines, and each line is about 6 miles long. Thus the overhead wires cost $180m, the buses cost $300m, and the electricity costs $48m over 24 years. It appears that equivalent diesel buses would cost $270m and use $330m in fuel over 24 years, servicing the same routes (just using the numbers I read from an article and doing the calculation manually). It would appear that trolleybuses cost ~$528m for those routes and diesel buses would cost ~$600m. However, that's not taking into account financing costs etc, which would probably make the trolleybuses more expensive than diesel ones since the upfront cost is higher. Also, this is for routes in San Francisco which are only 6 miles long; the economics may change for suburban routes.
That said, it doesn't seem like the costs are very different whether we choose trolleybuses, diesel buses, or battery-electric buses. It may be slightly more expensive to go electric, but not much.
Answer:
88% of CO2 travel footprint is generated by cars, 1% by buses.
They're called trollybusses and lots of cities used to have them. Apparently hundreds of cities in the US had them but most of them went away in the 1950's and 1960's. Currently they're only in use in Boston, Dayton, Philadelphia, Seattle, and San Francisco (List of US Trollybusses). I was recently in San Francisco on a tour bus and they said the reason they use them is the electric motor has more torque which is needed to go up the steep hills. I can't speak for why they're still in use in the other cities or why they went out of style in all but 5 cities. Growing up in Dayton I thought they were more common than they are since Dayton isn't that big of a city compared to the others on the list.
I see a lot of cars driving around 80% empty. To and from work, I must admit that one of them is mine.
You wastrel... At least my Ferrari is only 50% empty!
Vancouver, BC has a very extensive trolleybus network, with 265 active trolley busses. The system works quite well, and the busses do have battery backup, so they can go off the wires for short periods of time (to go around road construction, accident, pass a parked bus, etc...). As for the wires being ugly? I dunno, they're just part of the fabric of the city. There are some intersections though with rather impressive spider webs hanging over them. :)
...si hoc legere nimium eruditionis habes...
Seriously? Do you really believe a bunch of hippies put the breaks on something as profitable as Nuclear power?
Coal and oil lobbies, the folks paid to store nuclear waste instead of processing it into new power. Look at those folks. Follow the money. When anything of importance happens it's always money.
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A 30 mile range? What kind junk are the buying?
A BYD electric bus has a nominal range of 155 miles. It sounds much more reasonable to me.
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Here's what the US National Academies have to say: "One might think that airplanes, trains, and buses would consume most of the energy used in this sector but, in fact, their percentages are relatively small--about 9% for aircraft and about 3% for trains and buses. Personal vehicles, on the other hand, consume more than 60% of the energy used for transportation."
Completely eliminating emissions from buses would make only a small difference in the big energy picture.
That said, electric buses might not be such a bad thing. I'm driving an electric car these days and it is awesome (even if it isn't a Tesla).
I think it's very safe to assume that nearly every single person reading this site or writing comments here has ridden on a bus.
Yes, I'd prefer driving a Ferrari along a deserted Autobahn at top speed to riding a bus. Stuck in traffic and looking for ages for an ultimately expensive parking spot - that bus is looking good. Trains look even better especially with WiFi.