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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.
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.
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).
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).