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> Fuel cell buses do produce sufficient waste heat, but here’s the problem: it’s exceptionally expensive heat. Every degree of warmth comes from hydrogen — a fuel that’s costly to produce, store, and transport. Unlike diesel, heating with hydrogen’s waste heat is technically easy but economically painful. Isn't waste heat pretty much free by definition?
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Here in SE Michigan, one local transit authority ditched its new hybrid busses and returned to diesel ~15 years ago - because the TCO for the hybrid busses was so much higher that fixing the hole in their budget proved impossible.
What is TCO?
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> The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it! The problem is hybrid drivetrains are complex . You don't save anything on the complexity of a combustion engine and exhaust train (over 1000 individual parts that have to be machined at extremely low tolerances), but add a more complex transmission (it needs to be able to work with two distinct inputs)…
As a simple driver of cars, I've never understood why no one has mass produced an EV with a built-in generator. That would avoid the complexity of the hybrid drive train, allow easy plugin and short range electric-only travel, and could even be offered as an optional attachment. So what am I missing? Is the efficiency gained by the generator offset by losses through the EV system?
I'm just gonna assume the rest of the article is from the same source and close this tab.
Please also electrify garbage trucks
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Batteries have won this so hard (if you ignore CNG busses, which have existed forever and are "almost as good as hydrogen could be") - because even when they hadn't won it, you just needed more busses. Is it nice if the bus can do a driver's entire shift without a recharge? Sure! But if it can't, you just design the route so that the driver can switch busses and buy another bus. That means the technology problem is n…
Many bus routes have a 5-10ish min break at some point (usually the main station) in the route. If you can utilize those ten minutes to do a top-up, you can go a lot further on the same sized battery.
In short there are plenty of places to switch buses if you need to.
It's actually pretty simple to figure out. Making hydrogen takes energy. You lose some of the energy making the hydrogen. This is not a fixable problem. At least not unless you break the laws of thermodynamics.
When you have created hydrogen, you lose more energy compressing the energy. Then you have to transport it to wherever it's going to be pumped into the vehicle ... both of which take more energy. Then it goes into a fuel cell, which loses more energy. All these losses multiply. And if you know your maths, you know that multiplying numbers smaller than 1 means the result gets smaller and smaller. These losses are significant.
And we're comparing it with putting the energy into a battery directly. It has inherently better round trip energy. Even if hydrolyzers, and the infrastructure to store, compress, and transport hydrogen were free (which they are not), using hydrogen would still be more expensive than that. Because it wastes more of the energy that goes in. So, in addition to the energy losses, you also need to deal with infrastructure cost. On top of regular energy infrastructure.
Anyway, that's all theory. For practice, just look at market price of hydrogen. Most of that stuff is of the dirty grey hydrogen variety creating that wastes a lot of methane. So much, that it would be cleaner to just use the hydrogen in a combustion engine in the bus and you'd have less CO2 emissions. Expending more methane to make hydrogen to have less emissions makes no logical sense.
If you are using grey hydrogen, it is more expensive per mile than methane. Nothing can change that. If you are using green hydrogen, it is more expensive per mile than battery electric. Nothing can change that either. That's just physics and simple economics. Yes there are some innovations in this space happening that reduce the gap a little. But it's never going to be enough.
Right now it's not even close. Unless somebody is subsidizing the hydrogen fuel, you'd be paying way more per mile than with diesel. And not just a little bit. And a common reason to switch from diesel to BEV is that it actually costs way less per mile than diesel. So, instead of saving money, you are spending more money.
Subsidies are hiding the true cost of hydrogen. That's the only reason there are some vehicles on the road. As soon as the subsidies dry up, hydrogen transport use cases evaporate. There are of course plenty of other use cases where hydrogen is needed that make much more economical sense. Using scarce and expensive hydrogen for transport is a poor use of resources. The utopian world where we have vast amounts of hydrogen surpluses does not exist.
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Some hybrid drivetrains have fewer moving parts than a traditional ICE and are more reliable.
That undersells it. The data on hybrid drivetrains is pretty clear--it's definitely more reliable. Even mechanics will tell you that; certainly mine did, and he's not a masochist. Start+stop is hell on mechanical drivetrains. It's a no-brainer when purchasing a new car except that there's still a premium for hybrid, so the RoI might not be there given baseline reliability and depending on your preferences. Though the…
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Some hybrid drivetrains have fewer moving parts than a traditional ICE and are more reliable.
Sounds counterintuitive. Any references?
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Hills should never reduce the range, because the energy lost during climbing up is recovered when going downhill. This is one of the great advantages of electric vehicles with batteries, when properly designed. Electric buses with batteries are even more suitable for cities with hills than for cities without hills, because they provide greater energy savings over buses with ICEs. While I have never used buses with ba…
Regenerative breaking is not perfectly efficient, so you may loose a significant portion of the additional energy needed. Better EV systems are what, 70-80% efficient on the breaking efficiency?