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lenaitch said:
A couple of sites say about 9 litres of (distilled) water to produce 1kg of hydrogen. How far down the track that gets a train is beyond me. The energy required is about 50KWh/kg not counting the energy to compress.
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My math usually bites….but….So a 2MW windmill, running 24 hours at 10% capacity factor, produces 96 kg of hydrogen and requires 864 L of water.
If one assumes energy in equals energy out, that’s good for 4.8 mw/hrs. Or enough to power one modern freight locomotive for 1.5hours at full output?

- Paul
 
crs1026 said:
This is doubly meaningful for railways because in the truly sustainable zero-carbon picture, we can't afford to waste energy by continuing to rely on friction and conventional dynamic braking. There is simply too much kinetic energy wasted (ie released to the atmosphere as heat) that ought to be reclaimed. I suppose that hydrogen could be electrolyzed on board during braking cycles, but to my mind it does argue more for either regenerative braking (which requires wires) or battery recharging on board.

- Paul
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I think on-board hydrogen production won't be used, as the hydrogen would need to be compressed (its energy density at the atmospheric pressure is way too low). Having a high-pressure compressor on-board would add complexity, increase the risk of malfunction etc.

However, a relatively small auxiliary battery should do the trick. The battery could only be large enough to pull the train for 15 min or 30 min if it worked alone, therefore light enough not to affect the train weight too much, and yet sufficient to reuse the energy from regenerative braking.

By the way, even with catenary in place, pushing the energy back to the wires may be challenging in the context of long-haul rail lines. Such lines are usually powered with a voltage like 25 kVolts, while the city subways / LRT / trams usually have something like 600 - 800 volts. Lower voltage is not suitable for long-haul lines because the electric transmission losses are greater at lower voltage / higher amperage, and also grow with the transmission distance. But regenerating and safely feeding back the energy at 25 kVolts will have its own challenges, and I don't know if any such systems are in use today. So, even with catenary in place, an auxiliary battery might be a better choice for regenerative braking.
 
The really cool thing about hydrogen is that, unlike battery/catenary, which is net zero emissions, hydrogen is MINUS emissions.

Neither produce any GHG emissions when their energy source is green but all hydrogen vehicles use filters as the suck in air to produce electricity from the fuel cells and then push it back out AFTER it has been filtered. In other words hydrogen gets rid of good old fashioned pollution. That may not seem like a big deal in Canada but in the polluted developing countries like India and China it' a very big deal. The Hyundai hydrogen NEXO cleans out 99.9% of all particulate matter and, according to a Jan/21 article of altenegrymag.com, driving 350 miles filters 2,000 pounds of air.

Using hydrogen vehicles of all sorts could mean that just as we "drove" ourselves into this mess we can literally "drive" ourselves out of.
 
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ssiguy2 said:
The really cool thing about hydrogen is that, unlike battery/catenary, which is net zero emissions, hydrogen is MINUS emissions.

Neither produce any GHG emissions when their energy source is green but all hydrogen vehicles use filters as the suck in air to produce electricity from the fuel cells and then push it back out AFTER it has been filtered. In other words hydrogen gets rid of good old fashioned pollution. That may not seem like a big deal in Canada but in the polluted developing countries like India and China it' a very big deal. The Hyundai hydrogen NEXO cleans out 99.9% of all particulate matter and, according to a Jan/21 article of altenerymag.com, driving 350 miles filters 2,000 pounds of air.

Using hydrogen vehicles of all sorts could mean that just as we "drove" ourselves into this mess we can literally "drive" ourselves out of.
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This cannot trap the greenhouse gases, including CO2 or methane.

Can trap soot and other particles, so a massive fleet of hydrogen cars might have some positive effect on the air quality in a big city.
 
^ Exactly. It's no better for actual CO2 emissions but it does clean the air and in highly polluted cities, that is a big deal as their car ownership levels will only increase.
 
ssiguy2 said:
Using hydrogen vehicles of all sorts could mean that just as we "drove" ourselves into this mess we can literally "drive" ourselves out of.
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No. That is almost like saying drivers of Teslas are cleaning the planet with their HEPA filters, but you can be sure the filters on hydrogen vehicles are nowhere near as capable of cleaning the air. Also, as mentioned these filters do nothing for carbon capture.
 
^^ I know they do nothing for carbon capture as I clearly stated. They don't remove any GHG but they do clean out good old fashioned pollution which, in highly polluted cities especially in the developing world, is a big deal.
 
ssiguy2 said:
^^ I know they do nothing for carbon capture as I clearly stated. They don't remove any GHG but they do clean out good old fashioned pollution which, in highly polluted cities especially in the developing world, is a big deal.
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I think you are overestimating how much air they will draw through those filters. People are already running air conditioners with filters, furnaces with filters, vacuums with filters, etc. These vehicles aren't likely to have big air intakes with a lot of suction. It will be a drop in the bucket, not a big deal.
 
OnCorr contract closes this month.
https://twitter.com/x/status/1462846190572220416

1637634606184.png
 
What is the distinction between closing and awarded above?

Awarded sounds like when money rolls out the door, so that’s the milestone to wait for, no?
 
allengeorge said:
What is the distinction between closing and awarded above?

Awarded sounds like when money rolls out the door, so that’s the milestone to wait for, no?
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I believe "closing" refers to the financial closure of the project vs the announcement of the winner.

curious as its normally the other way around. they announce the winner then closure happens later on.
 
allengeorge said:
What is the distinction between closing and awarded above?

Awarded sounds like when money rolls out the door, so that’s the milestone to wait for, no?
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Possibly misspeak. The tender is probably closing (no longer accepting new paperwork from bidders) and after evaluating the submissions the winning bidder will be awarded next year.

Closing a contract usually refers to final signing (all conditions met or waived, financing/deposits in place, can no longer back-out) which happens well after you award the tender.

It's extremely rare for a government contract to reach financial close before the winning bidder is announced. The winning bidder needs to start hiring sub-contractors to close out contract conditions which requires telling them what they'll be working on.
 
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