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US schools can subscribe to an electric bus fleet at lower prices than diesel

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Re: US schools can subscribe to an electric bus fleet at lower prices than diesel

#221

Post by jjtheblunt »

jjtheblunt wrote: post #91
MengerSponge wrote: post #77

The secondary costs of running a diesel fleet are also huge! Diesel motors generate a substantial amount of fine particulate that is unhealthy for anybody, and particularly unhealthy for children. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC121970/ Even if an electric fleet is the same cost, changing over would save tons of money and alleviate tons of suffering. It's the right thing to do for any ethical reason you…

(Disclaimer: have driven pure electric for going on 7.5 years) It may be more complex: electricity generation is very dirty in some regions, such as where coal is burned. Is it more dirty than diesel emissions? I have no idea, but old diesels were nasty.

downvotes to ask a question? what has HN become?

Re: US schools can subscribe to an electric bus fleet at lower prices than diesel

#222

Post by erosenbe0 »

fiftyfifty wrote: post #137
kemiller wrote: post #119

Earlier quoted context omitted.

Engineering Explained did the math: https://www.youtube.com/watch?v=6RhtiPefVzM Spoiler: Well-to-wheels, BEV cars are better than the best gas cars (top end prius) even if the source electricity is 100% coal. The best is still not driving, but it's a step in the right direction.

There's also the fact that coal power plants tend to be pretty far from heavily populated areas. Even if the US power grid were 100% coal (which it is not) this would still be a win as far as cleaner air goes for a significant portion of the population. There's a big difference between a coal burning power plant's emissions 50 miles away and a school bus idling right outside your house in terms of air quality. That's…

The biggest source of particulate in my neighborhood as in most is recreational wood fires, where they allowed. The diesel schoolbus is nothing by comparison. Actually the fires are not allowed but people do it anyway and you need a drone to find them.

Re: US schools can subscribe to an electric bus fleet at lower prices than diesel

#223

Post by rootusrootus »

hedora wrote: post #216
ajford wrote: post #153

Earlier quoted context omitted.

Cold air impacting heath & capacity on the Li batteries, perhaps? Lithium batts tend to be finicky about their temperatures. Even my PHEV chevy volt de-rates the capacity if the ambient air temps hit less than 36*F.

Sorry to be the bearer of bad news, but that's mostly because it's a Chevy, not because managing lithium batteries in cold weather is an unsolved problem: https://news.yahoo.com/cold-hard-truth-evs-winter-103037566.... If you are in a climate where freezing weather is common, you might want to swap it for a different brand. There are comparably priced options that work well in the cold (just look at the chart in the…

My Tesla definitely lost range in the cold, too. I don't think it's just that Chevy (LG, you mean) doesn't know how to make a good battery pack.

Re: US schools can subscribe to an electric bus fleet at lower prices than diesel

#224

Post by erosenbe0 »

Ourgon wrote: post #120
jjtheblunt wrote: post #91

Earlier quoted context omitted.

(Disclaimer: have driven pure electric for going on 7.5 years) It may be more complex: electricity generation is very dirty in some regions, such as where coal is burned. Is it more dirty than diesel emissions? I have no idea, but old diesels were nasty.

> Is it more dirty than diesel emissions? I have no idea, but old diesels were nasty. When comparing old diesels to old coal power plants the power plants win by being more efficient but both belch out a lot of pollution. They also have the advantage of burning coal, a fuel which is available in abundance and does not need as much processing as crude oil does to be used in diesel engines. When comparing old diesels t…

I have found measuring in typical American neighborhoods that PM2.5 is raised the most when people burn wood for recreation or heat in the evening. It is much higher in the evening with a few neighborhood fire pits than during rush hour with a few diesel vehicles around.

This is also when residents have asthma symptoms too. To be fair they are more likely to be home.

So it is not cut and dry but if possible I would love to get rid of vehicle emissions as some particulate is too fine to measure.

Re: US schools can subscribe to an electric bus fleet at lower prices than diesel

#225

Post by erosenbe0 »

xxpor wrote: post #53
elihu wrote: post #30

Apparently there's an important patent on lithium iron phosphate (LFP) batteries that expires next month (on April 27th). I'm hoping that changes the economics on batteries and that LFPs become cheap and abundant, and widely available from a variety of manufacturers that aren't located in China. LFP seems like the obvious choice for large vehicles like buses unless there's some reason to really need to optimize for r…

Yes, that's a great point. Even if you ignore the usual idle time between the morning and afternoon runs, I have to imagine a range of 150-200 miles would cover ~95% of use cases. The bus problem therefore should be much easier than the long haul truck problem. Plus, there's no trailer so you could run the battery pack the entire length of the bus.

One problem is that 'diesel outages' on school nights are extremely rare or nonexistent. Maybe deliveries are late or pumps break but it seems like a solved problem. Electric trains are also a solved problem and are hardened from many power outages too.

Whereas some work needs to be done to harden the infrastructure at the school district level to avoid electric bus outages.

Re: US schools can subscribe to an electric bus fleet at lower prices than diesel

#227

Post by erosenbe0 »

skolsuper wrote: post #203
brg wrote: post #191

Earlier quoted context omitted.

Coal is used to establish a lower bound.

And maybe as the type of generation used for the marginal difference in energy required. If your country generates 90% of its electricity from hydroelectric and 10% from coal, you might still use coal for the comparison because hydroelectric power would be slow to add and the extra electricity for EVs would have to provided by coal

This is an important point. I live in Illinois which is over 60% carbonless mainly through aging nuclear investments. It would be naively optimistic to suggest that marginal demand will be only 40% fossil fuel since the nuclear will not be replaced.

Re: US schools can subscribe to an electric bus fleet at lower prices than diesel

#228

Post by kube-system »

olivermarks wrote: post #202
olivermarks wrote: post #152

Earlier quoted context omitted.

Ever been near an EV fire? They burn with the equivalent of a 220v welder across the whole battery skateboard, will literally melt aluminum wheels and body parts and require 20 tons of water to temporarily extinguish. There's a huge difference between an ICE vehicle fire, which is essentially rubber, upholstery and plastics burning sometime compounded by gasoline vapor and an EV thermal runaway trapped energy event.…

It's incredible to me that EV enthusiasts are such zealots they refuse to take into account the facts around practicality, pollution and fire risk, just choosing to downvote instead. A demonstration of a gasoline vs battery fire https://youtu.be/tuVxwmnhqP4

That's a demonstration of a $99 harbor freight flux core welder, not a "battery fire"

This is a EV fire: https://www.youtube.com/watch?v=CdaFk3w6rUY

And this is a diesel school bus on fire: https://www.youtube.com/watch?v=0nPrUdP_POg

If any vehicle catches on fire, you have to leave the vehicle, or risk death. There is no "safe fire"

Re: US schools can subscribe to an electric bus fleet at lower prices than diesel

#229

Post by worik »

bluGill wrote: post #207
VBprogrammer wrote: post #169

Earlier quoted context omitted.

> diesel buses breakdown regularly In comparison to what? Diesel engines in commercial vehicles are extremely reliable. It certainly could be possible for an electric bus to be more reliable, they certainly have less points of mechanical wear. However, there are a lot of power electronics going into charging their batteries and delivering the battery power to the motors.

Most parts that break on a car are common to electric or engines. Suspension, brake fluid (the brakes might last longer but the fluid should be replaced every few years), tires, doors, seats.

> Most parts that break on a car are common to electric or engines. Suspension, brake fluid (the brakes might last longer but the fluid should be replaced every few years), tires, doors, seats.

It is true that a lot of parts are in common. But there are a lot of moving parts, susceptible to failure in an ICE not in electric.

I spent a lot of money recently fixing an oil leak and replacing the cam belt on my ICE. Routine maintenance (the leak specifically was not routine but leaks generally are).

My next car will be electric, I hope.

Re: US schools can subscribe to an electric bus fleet at lower prices than diesel

#230

Post by elihu »

erosenbe0 wrote: post #225
xxpor wrote: post #53

Earlier quoted context omitted.

Yes, that's a great point. Even if you ignore the usual idle time between the morning and afternoon runs, I have to imagine a range of 150-200 miles would cover ~95% of use cases. The bus problem therefore should be much easier than the long haul truck problem. Plus, there's no trailer so you could run the battery pack the entire length of the bus.

One problem is that 'diesel outages' on school nights are extremely rare or nonexistent. Maybe deliveries are late or pumps break but it seems like a solved problem. Electric trains are also a solved problem and are hardened from many power outages too. Whereas some work needs to be done to harden the infrastructure at the school district level to avoid electric bus outages.

If there's a major power outage, the school probably won't be in session either. Though getting the students home might be a problem if power goes out in the middle of a school day and the buses haven't charged enough to get the students home. (If they have enough reserve capacity it's probably not an issue.)
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