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Hydrogen vs. Battery Buses: A European Transit Reality Check

cleantechnica.com

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Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#31

Post by deanishe »

londons_explore wrote: post #16
PaulKeeble wrote: post #8

Fundamentally battery buses are going to be cheaper to run. Regardless of initial outlay costs electricity that goes directly in with no conversion is achieving near 100% efficiency. Whereas with hydrogen that same electricity is being used to do electrolysis to get the hydrogen to begin with, compressing into fuel containers, travelling the fuel around the country and then pumping the fuel back in and then all the c…

> same electricity is being used to do electrolysis Nowhere in the world is electrolysis done at scale. Industrial hydrogen almost exclusively comes from steam methane reforming (SMR).

> Nowhere in the world is electrolysis done at scale.

Not yet. I know Siemens has some pilot plants running:https://www.siemens-energy.com/global/en/home/products-servi...

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#32

Post by 0xDEAFBEAD »

sightbroke wrote: post #14
api wrote: post #13

Earlier quoted context omitted.

Where I live in the US my kids still take “cheese buses” to school that haven’t changed a bit. They’re diesel and you can hear them blocks away. When they pull up with their air brakes going off and their diesel shifting to idle it sounds like one of those spice miner things from Dune going to work. If they ever go electric I’m not sure how we’ll know it’s time to take the kids out. Won’t be able to hear them coming.

> If they ever go electric I’m not sure how we’ll know it’s time to take the kids out. Won’t be able to hear them coming. I'm sure they'll just have an app.

How about playing a ditty just like an ice cream truck?

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#33

Post by vardump »

Kirby64 wrote: post #9
m4rtink wrote: post #2

I'm not really sure there is any place for a discussion - you would need a whole new infrastructure for hydrogen powered buses, while keeping a lot of the downsides of fossil fueled air breathing vehicles (eq. air filters filters regardless of if you burn the hydrogen or use it in fuel cells). With battery buses - you might need to slightly beef up the local transformer and installs some new wires and that's it. Or e…

> you would need a whole new infrastructure for hydrogen powered buses, while keeping a lot of the downsides of fossil fueled air breathing vehicles (eq. air filters filters regardless of if you burn the hydrogen or use it in fuel cells). Unless you burn the hydrogen, you aren't producing any emissions... unless you count water as an emission. Fuel cells don't produce any emissions. Burning hydrogen though, does prod…

Don't fuel cells require air without any contaminants, thus air filters?

So you still need filters, this not for the exhaust, but for the intake.

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#34

Post by Kirby64 »

vardump wrote: post #33
Kirby64 wrote: post #9

Earlier quoted context omitted.

> you would need a whole new infrastructure for hydrogen powered buses, while keeping a lot of the downsides of fossil fueled air breathing vehicles (eq. air filters filters regardless of if you burn the hydrogen or use it in fuel cells). Unless you burn the hydrogen, you aren't producing any emissions... unless you count water as an emission. Fuel cells don't produce any emissions. Burning hydrogen though, does prod…

Don't fuel cells require air without any contaminants, thus air filters? So you still need filters, this not for the exhaust, but for the intake.

Is that a real problem here? Air filters on ICE cars are easy and not that frequent. You need cabin air filters regardless for passengers, so changing those at the same time isn’t that much different. Filters are cheap unless fuel cell ones are super expensive for some reason.

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#35

Post by kumarski »

Hydrogen buses limp at an EROI of 0.5 to 1.5.

Losses via Gibbs free energy (237 kJ/mol to split H2O) and compression (20% of H2’s 120 MJ/kg.)

Barely cash in on the H2-O2 reaction (ΔH = -285.8 kJ/mol).

Battery buses, powered by lithium-ion cells, hit EROI of 2 to 4.

Redox heavy lithium mining (150 MJ/kg) drags it all down.

Charge-discharge losses (90% Coulombic efficiency)+ 5-10% capacity fade after 1000 cycles.

All trails diesel’s 5-10 EROI and 46 MJ/kg density.

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#37

Post by adgjlsfhk1 »

martinald wrote: post #19
londons_explore wrote: post #15

Earlier quoted context omitted.

Any decent sized installation will use current clamps at the local transformers to scale the charging rate up and down depending on other users in the local area. Ie. in the evening whilst everyone has their ovens on, charging might only be 3 kW per bus, but then at 1am when everyone has gone to bed, it can be 30 kW per bus. Using that approach, you can get far more capacity out of old infrastructure. Unfortunately,…

Not really. Buses need to be charged whenever, not just overnight (it creates enormous logistical problems otherwise). A typical bus route running 5am to midnight say is not going to last with one charge, depending on length. Also, if it is a cold night and everyone leaves electric heating/heat pumps on, what happens then? Noone can get to work the next day? Regardless most urban transformers are not going to have 15…

Lots of busses are split shift. i.e. they drive from ~6:30am to ~9:30am and ~4pm to 7pm. This means that a significant portion of your bus fleet will be able to charge during the middle of the day when energy demand is relatively low and there's a ton of solar power.

As an aside, we have so far really dropped the ball on level 1 electric vehicle chargers at offices. As solar power and EV numbers increase, it's pretty obvious that we want more cars charging during the day and fewer charging at night.

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#38

Post by Retric »

martinald wrote: post #19
londons_explore wrote: post #15

Earlier quoted context omitted.

Any decent sized installation will use current clamps at the local transformers to scale the charging rate up and down depending on other users in the local area. Ie. in the evening whilst everyone has their ovens on, charging might only be 3 kW per bus, but then at 1am when everyone has gone to bed, it can be 30 kW per bus. Using that approach, you can get far more capacity out of old infrastructure. Unfortunately,…

Not really. Buses need to be charged whenever, not just overnight (it creates enormous logistical problems otherwise). A typical bus route running 5am to midnight say is not going to last with one charge, depending on length. Also, if it is a cold night and everyone leaves electric heating/heat pumps on, what happens then? Noone can get to work the next day? Regardless most urban transformers are not going to have 15…

The critical bit for infrastructure is generally peak load not simply is anyone using it for anything. A few solar panels and a few batteries on-sight can create a lot of freedom here.

City busses don’t need that much energy because as they don’t move quickly, the cargo is light, and regenerative breaking offsets stop and go.

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#39

Post by wuming2 »

With battery powered scooters, battery powered mopeds, battery powered quadricycles, battery powered cars and battery powered buses zipping around I believe big oil and power corporations keep up investing into the hydrogen complex system just as an additional avenue to sustaining their representatives in politics. Who can contribute offsetting all of those investments by keeping up the flood of public subsidies to gas, diesel and all other revenue streams of their sponsors.

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#40

Post by 01HNNWZ0MV43FF »

rsynnott wrote: post #4

I think battery buses have comprehensively won this one, to be honest. The biggest hydrogen bus fleet seems to be 35 vehicles; there are many BEV bus fleets in the hundreds and some in the thousands. As a certified old person, I'm having trouble getting used to them. It is unnatural for a double-decker bus to pull up near-silently, and then move off smoothly when you get on. They are _supposed_ to vibrate violently a…

I'm surprised hybrids are so under-represented in this considerations.

Maybe I'm missing something but I would think at the scale of a bus, a hybrid is even more appealing than at the scale of a sedan.

Even locomotives and one or two earthmoving off-highway trucks have electric transmissions, making them series hybrids (With very small batteries not used for traction)

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