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Hydrogen vs. Battery Buses: A European Transit Reality Check

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

#171

Post by pipodeclown »

philwelch wrote: post #159
philjohn wrote: post #92

Earlier quoted context omitted.

Yes - but Hydrogen vehicles have not proven to match or even beat EV's in a lot of key metrics that matter. The biggest one is efficiency. 40% efficient is one figure I saw, versus 80% for EV's. Yes, you can refill quicker, but time to "refuel" EV's is dropping precipitously as well, and it's just all around safer than tanking around highly combustible liquid gas.

It's not really fair to compare the efficiency numbers directly that way. The efficiency for hydrogen is measured from the hydrogen fuel directly, but the efficiency of the EV is measured from the wall. In reality, generating electricity is about 40% efficient at best. Yes, there's also an efficiency cost to refining the hydrogen, but if we compare apples to apples and take a ton of LNG and use it to power an EV vers…

Sure but you should be comparing the goal end state, a world in which out energy consumption and generation is green, that's the whole point of our move to bev's and hydrogen. So you should be comparing energy generation by green means to power a BEV or using green energy to produce hydrogen to power a hydrogen car. In that world the whole energy production and consumption chain is about 3x as efficient for BEV, which in my mind means there is no way hydrogen is going to be competitive and we shouldn't waste valuable resources on persuing it.

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

#172

Post by laurencerowe »

crote wrote: post #148
01HNNWZ0MV43FF wrote: post #40

Earlier quoted context omitted.

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)

Hybrids are attractive when a short battery range is enough for daily use but you still do semi-frequent long-range driving. Rather than hauling around a heavy and expensive XL battery pack on your daily commute you haul around a tiny combustion engine. It's a great solution for people with range anxiety. Buses have a completely different use case. They drive a well-known distance, and every day is practically identi…

Hybrid buses were a huge win around cities before fully electric became viable and I expect they will continue to be important for rural routes.

Buses stop frequently so regenerative breaking is meaningful and crucially they avoid the horrible cloud of diesel particulates as they pull off. It was really noticeable as a cyclist. About 40% co2 savings over diesel in London.

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

#173

Post by lesuorac »

philjohn wrote: post #92
mmooss wrote: post #85

Earlier quoted context omitted.

If people followed that reasoning, there would be few EVs now because EVs had been tried for decades without success; so were airplanes and AI. If people quit as easily as you say hydrogen car manufacturers should, we wouldn't have much of anything.

Yes - but Hydrogen vehicles have not proven to match or even beat EV's in a lot of key metrics that matter. The biggest one is efficiency. 40% efficient is one figure I saw, versus 80% for EV's. Yes, you can refill quicker, but time to "refuel" EV's is dropping precipitously as well, and it's just all around safer than tanking around highly combustible liquid gas.

> Yes, you can refill quicker, but time to "refuel" EV's is dropping precipitously as well, and it's just all around safer than tanking around highly combustible liquid gas.

I always think of I, Robot where the protagonist gets on a motorcycle and immediately their passenger complains about how dangerous gasoline is.

While not for everybody, EVs have a really great property of being rechargable without much effort on your part. Just spend ~10 seconds plugging it in at home/work and then ~10 seconds unplugging it before your next time. Compared to waiting 20 minutes in line at Costco Gas to save 1 dollar.

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

#174

Post by ianburrell »

SoftTalker wrote: post #160
londons_explore wrote: post #24

Earlier quoted context omitted.

either release to the atmosphere or inject into an oil well to increase well production.

So H2 fueled vehicles are just indirectly methane fueled, and not carbon-neutral. Why not electrolyse water? It's not efficient, but if you use solar energy who cares? Set up a plant near the ocean and just let it run. All the inputs are essentially free.

Electrolysis uses a lot of electricity. Solar energy is not free, others pay money for the energy. What are you going to do with the hydrogen? It is better to use the electricity.

Green hydrogen only makes sense when everything is electrified and electricity is cheap. It might be needed for things like industrial heat or shipping where need fuel.

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

#175

Post by m4rtink »

satiric wrote: post #157
m4rtink wrote: post #132

Earlier quoted context omitted.

That started showing up maybe ~5 years ago ? Googling a bit I found this article about the first series produced parcial trolley busses (eq. battery equiped) being delivered in 2018: https://www.bmhd.cz/aktuality/aktualita.php?1481 Since then it certainly expanded a lot & there are now regular lines that have the trolleybus go part of the line under its own power, like the recently introduced line to Soběšice: https:…

Do the poles fall off the wires a lot? Our trolley buses in Seattle have a bit of a problem with that. According to the folks I know in San Francisco, theirs do too. They're great otherwise though. Seattle's newer trolley buses can operate off the wire for about 3 miles/5 kilometers (on a LiFePO4 battery) which helps a bit.

I have seen it happen a few times, but it does not seem to happen very often. I don't think I ever saw it happen when riding a trolley bus - usually I saw a stopped trolleybus with the driver stepping out & reatacching the collector poles before driving away. Took a couple minutes at most.

It was usually in some tricky spots - trolley wires crossing streetcar wire on Konečného náměstí (yeah, we have both :) ) or on the top of the rather steep slope of the Kotlářská street next to the Natural sciences faculty of the Masaryk university.

I guess the new trolley busses with batteries and poles thatr can be stowed automatically might be even better for this - no need to fix the poles immediately, but wait for a regular stop or even the line terminus & just use the battery.

Also once when touring one of the trolleybus depos (the small one in Husovice) the local maintenance chief mentioned that the one roundabout wired for trolley buses (yes, that exists) is a pain to maintain & maybe they could scrap it in the future, with the busses crossing it on batteries instead. :)

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

#176

Post by mbirth »

grapesodaaaaa wrote: post #96
philjohn wrote: post #92

Earlier quoted context omitted.

Yes - but Hydrogen vehicles have not proven to match or even beat EV's in a lot of key metrics that matter. The biggest one is efficiency. 40% efficient is one figure I saw, versus 80% for EV's. Yes, you can refill quicker, but time to "refuel" EV's is dropping precipitously as well, and it's just all around safer than tanking around highly combustible liquid gas.

Let’s not forget that the highly combustible liquid gas either needs to be stored with complicated cooling or under immense pressure (feel free to disprove me if I haven’t kept up with technology). It can be done safely, but adds a lot of complexity on top of all the complexity needed for ICE engines. Your points are also great.

Add to that the problem of “boil off” / “pressure venting”. There are some cars that empty their hydrogen tanks on their own in about 2 weeks. Just because of this issue.

There are new ways to store hydrogen, but these also need external (=from a separate battery) electricity to release it again and the process is slow and doesn’t provide enough amperage, so it can only be used to slowly charge another big battery that is required for these cars to be able to drive.

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

#177

Post by satiric »

m4rtink wrote: post #175
satiric wrote: post #157

Earlier quoted context omitted.

Do the poles fall off the wires a lot? Our trolley buses in Seattle have a bit of a problem with that. According to the folks I know in San Francisco, theirs do too. They're great otherwise though. Seattle's newer trolley buses can operate off the wire for about 3 miles/5 kilometers (on a LiFePO4 battery) which helps a bit.

I have seen it happen a few times, but it does not seem to happen very often. I don't think I ever saw it happen when riding a trolley bus - usually I saw a stopped trolleybus with the driver stepping out & reatacching the collector poles before driving away. Took a couple minutes at most. It was usually in some tricky spots - trolley wires crossing streetcar wire on Konečného náměstí (yeah, we have both :) ) or on t…

Oof yeah I can see how a roundabout would cause a headache. I really enjoy the trolleybuses; there are some plans in place to expand the system, but not enough IMO.

We also have both streetcars and trolleybuses, and some strange junctions like the one at 5th and Jackson: https://maps.app.goo.gl/4TuLXmRLY5yK6HGJ6

There are some nice blog posts from a Seattle bus driver that go over some of the nerdy details of our system: https://www.nathanvass.com/blog/i-dont-know-what-a-trolley-i... https://www.nathanvass.com/blog/i-dont-know-what-a-trolley-i...

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

#178

Post by martinald »

crote wrote: post #149
martinald wrote: post #7

Earlier quoted context omitted.

While I agree with you; just to be clear it's not "slightly" beef up the local transformer. If you imagine a medium sized depot with 50 buses stabled at any one time, and 300kW chargers (I believe you could go higher), that's 15MW peak which is not trivial to add in many cities overnight. You really need some sort of HV connection for that kind of load, the existing local LV distribution grid isn't going to handle it…

You wouldn't need 300kW chargers, though! Battery buses have a battery capacity of around 400kWh. Assuming they are stabled for 6 hours overnight, that's only a charging power of 66kW. Suddenly your depot needs a connection with a peak capacity of 3.3MW instead of the proposed 15MW. This can get significantly better in practice. There's a peak transit demand during commute hours, but that means there are quite a few…

You're oversimplifying on many angles.

Firstly you have charging losses - and you're assuming that you can charge at the same rate consistently over the cycle of the charge.

Secondly, doing it like that massively reduces operational flexibility. If buses are all late back (bad traffic for example) you would want to charge more aggressively than the 60kW. You can't so you're going to have buses that are low on charge the next day.

Finally, it's all a bit moot. In most areas you do not have 3MW of spare capacity on the LV network to suddenly plug into. You're going to need a new HV connection or dramatic LV grid reinforcement, so you might as well put a decent connection in at that point. The cost is basically the same, most of the cost is in permits and civils.

Your idea to place charging points at turnaround points is also not as feasible as you make out. It's incredibly hard to do that (TfL massively struggles to get planning for a simple toilet block for drivers at turnaround points) and they are not designed in a way to have buses in a certain exact position to charge often. And even if you could if buses are late they cannot skip the turnaround like now as they need to charge. This will cause massive cascading delays down the route for the rest of the day.

Grid connections are the reason rollout is so slow, at least in the UK. There is relatively plentiful funding for it but most depots are now completely maxed out in power availability - any spare capacity has already been used and the LV DNO queue is 10+ years for local reinforcement.

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

#179

Post by martinald »

bmicraft wrote: post #105
adgjlsfhk1 wrote: post #37

Earlier quoted context omitted.

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…

Where do you live that buses aren't running during most of the day? That just seems absurd to me. Buses in my city run at only slightly reduced (from the rush hour peak) intervals for the whole day

Agreed, I assume this is a very US centric viewpoint. Wherever I have been in Europe the schedule is basically the same throughout the day, with reduced frequency in the evenings. Potentially slightly higher at rush hours, but nothing dramatic.

Not sure why you are being downvoted.

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

#180

Post by deepsun »

linedgolyi wrote: post #76
deepsun wrote: post #50

Earlier quoted context omitted.

You'll see the bus on your phone / home hub. Like ridezoom company does, you see whenever your kid checked in/out of the bus, and the bus itself on a map.

Hopefully in a way not tied to some commercial third party. People should be able to reliably go to public school without having to accept an arbitrary third party contract

Oh don't worry, you won't even get asked. It's your school district decides to pay a lot of your tax dollars to the third-party company.
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