this post was submitted on 17 Nov 2024
609 points (99.4% liked)
Technology
59599 readers
3455 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
I have a generally negative impression of hydrogen because many of the intended use-cases seem to be a cover story for the gas industry to keep existing, which it very much should not be any more.
Do you know any use-cases where hydrogen is truly warranted, outside for example steel production, which I think might be legit?
The case for an H2 economy is one entirely based on Green H2 made from surplus renewables which are needed most days to have enough renewable energy every day.
That gas companies know how to build pipelines, distribution, and make metered gas sales to customers is a path for them/employees to remain useful without destroying the planet.
Commercial vehicles has legitimate benefits of lower cost from H2 FCs than batteries. Quicker refuel times. Aviation especially benefits from redesigning planes for H2 for the weight savings. Trains/ships need the power/range. Trucks/cars can use the range extension, and could use H2 as removable auxiliary power for extended range.
Those vehicles can also charge the grid, and as hybrids, EVs or grid can be charged from static H2 FCs. For building energy, a FC can provide the usual fraction of domestic hot water from its waste heat. The electric monopoly problem is an opportunity for both producers and consumers to bypass their high rates and fees. Ammonia and fertilizer is traditional use for H2. There needs to be a carbon tax to move away from giant fosil H2 plants powering next door giant ammonia/fertilizer plants.
Hydrogen electrolysis is just one form of electro chemistry. Other fertilizers can be made from simpler versions of the process. It's not so much that H2 is essential in unlimited quantities, it is that electro chemistry is possible ultra cheaply when there is an abundance of renewables that provides enough energy every day to power their locality. H2 is special as a chemical for being transportable/convertable as mobile or other elecricity/heat.
Wouldn't it be more compelling to store it in other types of batteries instead of H2 primarily?
I honestly don't think H2 is a good idea for these use-cases. H2 distribution is a different beast than natural gas distribution, on top of gas combustion just generally not being particularly good compared to common household electrical counterparts (induction for stoves, electric for ovens, heat pumps for heating buildings and water).
I imagine refueling times is not necessarily going to be critical for all types of commercial use-cases.
Aviation struggles with the relatively low energy density in H2.
Trains should essentially always be running on catenaries.
Boats might be able to make use of H2, I'm not super familiar with the issues affecting them.
Long-hail trucking should broadly be replaced by the much more efficient rail shipping.
Cars run pretty much fine on electric as is, I'm not sure the case for making H2 cars is compelling enough to be warranted.
This might be a good niche for H2 to fill.
All in all, I'm still not convinced that large-scale H2 buildouts is a good use of our resources, but there are definitely a few compelling niches that it can fill. We need to be wary of them being co-opted by blue hydrogen fossil fuel companies though, which often seems to be the case today.
The economics of batteries are that they must be fully charged and discharged daily to pay off. A 2 day average cycle is double the cost of energy in using them.
In spring and fall we get positive happy headlines that "all electricity was provided by solar/renewables" during 1 hour or so during a day, or that electricity prices went negative. These seasons are low demand with good enough sun. Batteries get let those days/seasons get to 24 hour power from renewables, but then summer heatwaves won't fill demand even with more sun, winter will not charge up the batteries enough. H2 electrolysis is needed to have enough solar and batteries to cover all those needs, and then use H2 to cover winter supplemental needs. H2 supports not just more solar, but also more batteries. Makes sure batteries can always discharge before the sun comes up.
Commercial vehicles, need to pay operators for downtime, and downtime is time not earning revenue. it is a bid deal to them.
At $4/gallon diesel/kerosene, a plane will cost 100x in fuel as its purchase costs. We can already produce green H2 at $2/kg compressed. Which is equivalent to $1/gallon gasoline fuel when used in a FC. Redesigning planes, and delta wing for long range specifically, for H2 is worth liquifying the H2 for the weight savings and range over compressed. It's also that price that can compete well with commercial EV charging.