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Why do transit agencies keep falling for the hydrogen bus myth?

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Re: Why do transit agencies keep falling for the hydrogen bus myth?

#51

The electric airplane is another myth. There is no known battery technology, or one on the horizon, that can provide a large enough power/weight to make them practical. The investors are getting bilked.

Beta Technologies is already shuttling cargo between bases/depots for the US military with their eVTOL aircraft.

Demonstrated range of over 300 nautical miles. Significantly higher reliability than helicopters previously used for the same task, and much cheaper.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#52

The electric airplane is another myth. There is no known battery technology, or one on the horizon, that can provide a large enough power/weight to make them practical. The investors are getting bilked.

Really? The Beta Alia CX300 just completed a coast to coast journey (Vermont - Santa Monica). Range of about 338 miles using 200kwh of completely unremarkable ~150wh/kg batteries. With 500wh/kg batteries being announced from multiple manufacturers now, that range should improve pretty quickly.

> There is no known battery technology, or one on the horizon,

The planes and batteries are getting there.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#53

Because people are allergic to hybrids and I don't know why "Electric is short range, fuel is expensive, guess I have to pick one" The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it!

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.

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#55
> 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?

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#56

Earlier quoted context omitted.

This depends a lot on local climate and topography. Seattle has kind of been a bust with them because the hills really reduce the amount of charge, and on top of that the existing bus depots are already full, so switching to electric only would mean having to find and locate space for more bus depots, which is quite difficult.

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?

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#57
post #14

Earlier quoted context omitted.

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…

The stop-start nature of city busses makes them a real low hanging fruit for battery electrification, benefiting from instant torque to start and regen to stop and, as you say, fixed known routes within larger fleets. The only nation that seems to have capitalised on this basic fact is China which bootstrapped its EV industry on busses, pulling ahead from 2010 and hitting 90% of global market share for EV busses in 2…

(At least in King County Metro) the newer diesel-electric buses are series hybrids that use electric motors for traction, and diesel generators to power a small battery. So the low hanging fruit of electric traction was already “picked”. You can look up the bus model online - New Flyer XDE class

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#58

Because people are allergic to hybrids and I don't know why "Electric is short range, fuel is expensive, guess I have to pick one" The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it!

(At least in King County Metro) their newer diesel-electric buses are series hybrids that use electric motors for traction, and diesel generators to power a small battery. The drivetrain seems smart but maybe other agencies use it less? You can look up the bus model online - New Flyer XDE class

Re: Why do transit agencies keep falling for the hydrogen bus myth?

#60

Because people are allergic to hybrids and I don't know why "Electric is short range, fuel is expensive, guess I have to pick one" The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it!

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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