humanspiral

joined 1 month ago
[–] humanspiral@lemmy.ca 1 points 5 days ago

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.

imagine refueling times is not necessarily going to be critical for all types of commercial use-cases.

Commercial vehicles, need to pay operators for downtime, and downtime is time not earning revenue. it is a bid deal to them.

Aviation struggles with the relatively low energy density in H2.

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.

[–] humanspiral@lemmy.ca 2 points 5 days ago (1 children)

I don't know that processing silicon is a polluting activity. There is heat involved, and some Chinese producers are 100% solar powered for their processing. Though I'm sure bulldozers or shipps/trucks are involved in obtaining sand.

I'm not a fan of any appeals to gatekeep energy use to "just essentials" instead permitting growth that people want, and cleaning up the energy use involved.

[–] humanspiral@lemmy.ca 1 points 5 days ago

The difference is that the electrolysis can be done at producer convenience. Sometimes wholesale electricity prices (midday due to high solar penetration) are negative or ultra cheap. Transporting H2, even by truck, can be cheaper than the US typical 8c/kwh electric transmission charge. For many areas, enough solar in winter has 3x more summer production and essentially unusable. A balance of solar and H2 produced in summer, can provide the cheapest necessary energy for winter. An alternative is summer exports with winter imports.

Batteries alone are also subject to curtailment, or not enough charging in winter. H2 can be stored at $1/kwh, where a pipeline is free transmission of withdrawals different from deposit locations. The energy efficiency round trip is less important than the $ efficiency of energy delivery.

[–] humanspiral@lemmy.ca 1 points 5 days ago (2 children)

The expense part gets taken care of with OP's solar prices. Battery costs help too.

[–] humanspiral@lemmy.ca 1 points 5 days ago (2 children)

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.

[–] humanspiral@lemmy.ca 2 points 5 days ago (4 children)

HVDC is much more expensive than Hydrogen pipelines, which doubles as storage and transmission, and can provide continent wide resilience, even when local renewables provide much cheaper power when it is available than either long distance electric or H2 power.

[–] humanspiral@lemmy.ca 2 points 6 days ago

there is some nuclear tech that can use nuclear waste as at least part of it’s fuel

Those are less competitive, and salt reactor attempts have historically caused terminating corrosion problems. The SMR "promise" relies on switching extremely expensive/rare/dangerous plutonium level enriched fuel, that rely on traditional reactors for enrichment, for slightly lower capital costs.

[–] humanspiral@lemmy.ca 3 points 6 days ago (4 children)

And cheaper solar and batteries permits cheaper Hydrogen which provides unlimited and 100% resilient renewable power, and still cheaper than nuclear.

[–] humanspiral@lemmy.ca 3 points 6 days ago

Batteries can be containerized in modules, with a turnkey connection that remains mobile. Solar can use those containers as support structure. Hydrogen electrolyzer/fuel cells can also be built in same containers.

[–] humanspiral@lemmy.ca 1 points 6 days ago

Also the budget and timeline is always understated, because otherwise government could withdraw funding if they don't sink a little more cost into the budget every year.

[–] humanspiral@lemmy.ca 1 points 6 days ago

It is very poorly implemented. "Builder grade" solar panels in a "smallest compliant" configuration with no concern for architecture to benefit from solar takes place. Builders are intentionally putting the shittiest solar to reduce value of the homes they build so that they can complain about the policy.

[–] humanspiral@lemmy.ca 6 points 6 days ago (3 children)

Manufacturing photovoltaics takes a huge pile of chemicals that need to be handled properly to not cause any harm to the environment

Source for this? Cadmium is exclusive to 1 US manufacturer.

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