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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."
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.
I heard that the top 16 largest container ships (burning bunker fuel) pollute as much as all of the cars on the road.
Link
Maybe we need to look there... Come on, how much difference will a few million cars make when compared to just one of those ships?
Procrastination; I'll think of a sig tomorrow.
In San Francisco a good percentage of our bus fleet is electric with overhead wires, so the tech is still there, works great, and is not as expensive and problematic as batteries. Trolley buses, look it up. Only issue is the wires are U G L Y
The newer buses even have enough battery power to go a block or two off the wires on battery power and pass an obstruction, something that would bring the old trolley bus system to a standstill.
San Francisco still has a ton of trolley buses. We also have old and new trolley cars on rails.
I much prefer electric trolley buses to diesel and natural gas buses. Trolley buses have insane acceleration, presumably better even than battery-electric buses. Without traffic they can really haul-butt, which admittedly sucks if you suffer from motion sickness (as I do), but at least you can get off sooner.
And, personally, I prefer the wires. They give the bus line a feeling of permanence similar to rails. From transit agencies' perspective the ability to easily re-route is a big win. But from commuters' and property owners' perspectives, that's a huge negative.
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.
Which is the majority of bus travel that the referenced article is talking about. While the bus being promoted LOOKS like a grey-hound type replacement that is NOT what they are being put in to service for. They are being directed toward large metropolitan areas over routes that are 'well trafficked'; one example being a 17 mile route in/around LA. There are different solutions for different problems. Even in the smallish city I grew up in a 17 mile route was 'nothing major' to deal with. As another poster noted the overhead lines do look messy but are we going to give up a technology because of it's aesthetics? And as another poster noted a number of these 'trolley line' buses now sport batteries to get them around obstacles/construction that requires a minor rerouting, a perfect blend of old & new technology. But I guess if we continue to forget our past we are either doomed to repeat it....or forget it.
There has been talk about about sail-assisted cargo ships for some time.
http://www.sail-world.com/crui...
SJWs are the new boogeyman. -Me
As an investor in renewables, China is well in the lead of ever other nation.
Either the Pew report or that article is giving you an incomplete picture.
China, despite being a leader in nuclear and renewable power, is also going balls out to build coal-gasification plants.
China will be closing some coal power plants, but only ones nearest to its major cities (and responsible for the atrocious air quality). These will be replaced with 50 coal-to-gas plants in NW China and the synthetic natural gas will be shipped to new power plants in/near the cities. Cleaner air, but more CO2 per unit of power.
As a side note, China is responsible for about half the world's coal consumption, with no declines predicted.
[Fuck Beta]
o0t!
It's my understanding that the electricity for the trolley buses is free. San Francisco owns the Hetch Hetchy Dam and all city services are run off that power. In fact, under the terms of the Raker Act San Francisco isn't supposed to use it for anything but public services in the city, although they've never strictly complied with that requirement.
The soviets have had reactors go critical and melt through the hull. The original nuclear-powered Icebreaker Lenin had this happen at one point. Grigori Medvedev wrote about it in The Truth About Chernobyl. He was very high in the Soviet nuclear programme before he defected to the UK.
If all nuclear vessels were operated to the standards of the US Navy then that'd be one thing, but merchant shipping is lucky to not have a hull covered in rust and bilge pumps running constantly to keep the ship from foundering.
Do not look into laser with remaining eye.
However, heavy bunkers are hell on the top cylinder in slow speed diesels (110 rpm or less). Valve metallurgy has
negated a lot of the effects of this and although steam plants can use heavy oil they lose a lot of energy transfer
and hence are not very efficient. Medimum speed (Above 200 rpm) have terrible reliability problems trying to burn
bunkers. A lot of companies insist that the cheap fuel saves money but it's double edged versus the overtime they
pay engineers for valve maintenance. Exhaust temperatures tend to be a lot higher burning bunkers (150c or so
higher) and the risk of stack fires with high sulfur/carbon content increases dramatically if any turbo oxygen reaches
the stack. Total hydrocarbon consumption by ships as a percentage of all consumption is probably not that high and
alternative vegetable fuels work quite well for the most part in either slow or medium speed engines. The veg oil
market doesn't have the volume to supply all forms of transportation but in a narrow segment such as shipping,
it might be viable as an alternative. The billionaire shipping companies have been screwing around with the fuel
cost/maintenance cost issues for years. They'll do anything to save a penny. Tax breaks and subsidies to use
alternative fuels makes sense in this case. (In my belief.)
Wrong !
In many ways, military and civilian water cooled reactors of today should have been 40 years ago technology.
Basic Nuclear in the USA research pretty much stopped in the late 60s during the Nixon administration.
The really sharp, ambitious nuclear scientists (from the Manhattan project), wanted either metal cooled fast reactors or thorium molten salt reactors.
Nobody wanted a water cooled reactor. A water cooled reactor was the Navy's solution to the Navy's problem with Navy's knowledge set.
Plus lets compare the world's largest Navy nuclear reactor.
The latest nuclear carriers use 2 A1B nuclear reactors, rated at 300MWt each.
And those reactors run around 50% power most of the time.
A full sized civilian reactor usually is 4000MWt (1300-1400 MWe).
Very, very different beasts.
The navy doesn't need inherently safe reactors, they have extremely competent officers running its nuclear reactors.
Civilians need inherently safe, walk away if anything goes bad, reactors.
With molten salts we can built 500-1000MWt reactors that are far safer AND far more efficient than the 4000MWt water cooled reactors.
I have spent over 200 hrs studying lectures, papers, analysis, for molten salt tech.
And why they were never seriously pursued. No technical reasons. Political reasons instead.
While I prefer molten salt reactors over sodium cooled fast reactors, the later are also way safer than water cooled reactors. Killed in the 90s by Clinton, Al Gore and John Kerry. By order of big coal and natural gas interests.
If you want nuclear research to restart, we first need to combat the real enemy of nuclear power today which is the public, that was carefully fed lie after lie about nuclear power, and the BIG lie that solar+wind can do the trick (THEY CAN'T).
They use what is called a "Viscotherm" which is a 10kw electric heater to warm the fuel. Not exhaust.
Sorry. Been this way since the steam days. They use either an auxillary 500kw diesel (cat 396, Jimmy
1271) or an online steam Turbo generator in the case of a steam plant. This is a fatal negative feedback
loop in the steam case. If you lose the TG you lose fuel, hence the diesel backup for the viscotherm.
Yes, I'm a marine engineer.
Amazingly it won't stop idiotic local councils from ripping them up, even today. Here's a good example - http://www.stuff.co.nz/national/10202967/Wellingtons-trolley-buses-to-go
I'd assume the burnt sulfur goes into the air and comes down in the rain when burnt in a ship much like when burnt in a coal plant
No. Ships have much shorter smoke stacks than power plants, and most modern ships have horizontal funnels that blow the smoke out to the sides. They are designed to keep the smoke low, to prevent it from traveling too far. This is a problem when ships are in port, but that can be prevented by hooking them up to shore power, so they don't need to run their boilers to generate their own electricity.
Nuclear power has already been tried on a merchant ship.
The problem is the manpower to operate it just doesn't scale well to something as small as a ship. The reactor itself scales just fine and performed admirably (used about 163 pounds of uranium or a hair over one gallon, instead of 29 million gallons of fuel oil during its 10 years of operation). But the additional manpower and training needed to operate and maintain a nuclear reactor instead of a diesel engine killed its cost-effectiveness at transporting cargo. You're basically using the same amount of trained staff as needed to operate a reactor to power a small city (a few hundred MW), except you're only powering a ship (74 MW).
Maybe molten salt reactors or some other tech will be easy enough to maintain that nuclear could supplant diesel for cargo ships. But it isn't going to happen with light water reactors. Even the U.S. Navy sees this lower limit, and uses diesel or gas turbine engines in anything as small as a cruiser (the previous Virginia-class cruisers were nuclear, but the current Ticonderoga-class uses gas turbine engines).
I grew up using Wellington's electric buses my entire life. ...
And now the council is going to scrap the lot of them - how fitting that slashdot should run an article
http://www.stuff.co.nz/national/10202967/Wellingtons-trolley-buses-to-go
Politicians in the pockets of industry again...
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.
Seattle used to have busses with both pantographs and diesel engines. In the transit tunnel, they'd connect to the wires and go all-electric. When the left and drove on city streets, they'd lower it and start the diesel. They ended up replacing most if not all with hybrids (meaning they do burn diesel in the tunnel too), which I believe turned out not to save any fuel or electricity.