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The FactoBattery

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32 pointsbrilee31 comments

> Renewable energies are very annoying to grid operators. Their energy production is unreliable,

I don't know if the people involved find it annoying though I doubt it. But the second assertion is flat out untrue.

It is not unreliable, it is reliable but intermittent. Wind power availability can be fairly well forecast.

and peak solar also typically lines up with peak air conditioning demand

"Typically" isn't good enough though. If you have a hot, summer thunderstorm with no sun but still 100F+ temperatures, someone needs to create that energy for the air conditioners.

So the peaker-gas plant still have to be built, and then run at a lower utilization / less profits, for the community.

Either that, or accept that everyone loses power / not enough AC during those times. I've been to the Philippines, some people can live like that (intermittent utilities: sometimes you have running water / electricity, sometimes you don't) but its not the standard of living USA is used to.

They are unreliable and unpredictable for the scales considered in the energy market.

The imputed comparison between hydrogen electrolysis and battery storage is not apples-to-apples:

- The hydrogen numbers are from a Fraunhofer (vendor) report. They discuss the cost of the components of the electrolysis system itself.

- The battery numbers are from an EPA report. They include the total cost of batteries as a line item ($200/kWh), and go on to add in permitting, construction, grid hookups, land acquisition, etc.

Unsurprisingly, a regulatory agency analysis of system cost is more pessimistic than a vendor's analysis of product cost.

The report did say 72M for just electrolysis, but I used 120M in the analysis, an estimated +66% markup for all the other factors that you correctly point out as missing.

Flywheels are an alternative to batteries for grid stability. Very little interest in adding them due to the continued advancement of batteries. I'm actually surprised how often they're missed as a viable solution.

I always feel uneasy about flywheels. While batteries can be potential fire hazards, flywheels are potential bombs.

From what I've seen, a somewhat more ideal scenario would be a flywheel battery station on every street and a chemical battery in every home.

In that scenario, neighborhoods would take a while to fill up their capacity but once those capacities were full they could easily handle brownouts and temporary disruptions without affecting the larger grid.

That sounds incredibly unsafe.

Why? Many hospitals utilize flywheel storage. Probably safer than having a giant pile of extremely reactive lithium sitting on every street corner.

iiuc, flywheels would slow down/lose energy over time due to friction. They might be useful for smoothing out peaks, ie when clouds pass over a solar farm. But for longer term storage, arent batteries better?

Which company is making an economically competitive solution, though? What's the feasible density?

https://news.ycombinator.com/item?id=34370740

Does this show that current markets are working? Seems like the lowest cost energy storage solution are NG peakers, and it does seem like the US has a lot of gas energy production: https://www.eia.gov/tools/faqs/faq.php?id=427&t=3

> Does this show that current markets are working?

Depends on your definition of working. It wasn’t explicitly stated, but I think it’s implied that natural gas is bad, or at least, less desirable than renewable only.

I think something missing from the article’s analysis is that solar power can be, in a lossy manner, sent (north) eastwards in the US. If California is close to producing a surplus of solar power, then why not send it to seattle/Arizona. Northwards accounts for unbalanced solar load, and eastwards lets excess daytime Cali sunlight fuel the post-sun evening boom towards the east.

California has a unique opportunity to pioneer a lot of renewable energy tech. The (on average) rich population can afford higher costs, to buy at-home solar and battery packs. The geography and climate means plenty of renewable energy. The localization of energy production and storage could make the grid resilient, and distribute costs so there’s no government mega projects to politically grapple with. Unfortunately a lot of that won’t translate well to the rest of the Us, especially the Northern regions with much less generous weather. Unless California can find a way to export their energy, the rest of the US won’t benefit nearly as much.

Could residential hydrogen generation, storage, and use be viable? Say you have solar, a water supply, and a big hydrogen tank. Any excess electricity can make hydrogen by electrolysis and store it to be used for heating and cooking. No expensive transport or exotic fuel cells. In arid climates the water vapor from burning it could even be captured.

The two big problems I see are that hydrogen is trickier to pipe than natural gas, and if there is no hydrogen economy to make backup deliveries, how do you keep up with essential heating when there isn't much excess electricity?

Residential anything will scale worse than the same process done on an industrial scale. Especially if it's the sort of complicated mechanical process that requires maintenance and safety considerations.

The big question is "how can we build a H2 electrolyser whose fixed cost isn't prohibitively expensive". Everything else will fall out from there. That will mean finding something else to use for the electrodes other than platinum.

Why bother when you can just sell the electricity to the grid? What advantage does all that extra complication get you? Much cheaper to just scrap the gas hob and buy an induction hob and replace some of the pans.

This is for when you can't "just sell the electricity to the grid", either because it is congested or because you have more electricity at the moment than there is consumer demand available. An example off the top of my mind is in the North of the Netherlands, where the power cables from several major wind parks will come ashore. During periods of high production and limited demand, like a storm during the weekend, there will be more production than they can shift with the infra available. Shell is building a multi-GW electrolyzer plant to absorb the excess energy.

There are also some industrial applications like steel smelting where some chemical reducing agent is required, which would be difficult to convert to electricity-only operation. Fertilizer production is also pretty hydrogen-heavy.

That's interesting, I never considered cooking with hydrogen gas. I think I assumed the steam production and very rapid burn would make it unsuitable, but this article from, er, the American Hydrogen Association says otherwise: https://www.clean-air.org/faq.html

Combustion of methane also produces steam, so that would not necessarily make a big difference. Hydrogen also does not necessarily burn any faster than other gases used for cooking, you just need to adjust the cooking apparatus for a different rate of gas flow.

This comment just helped me to answer the question of why there's instantly condensation on the outside of the pot when the gas stove is lit. That one had me curious for a while. Brilliant, thanks!

Referencing recent stove discourse, it's likely to be better since it won't produce carbon monoxide.

i think this is avery real possibility.

This company is building such a system, to shift home rooftop solar power into the winter. (To shift from day to night, batteries are more efficient.) https://www.homepowersolutions.de/en/product/

Hydrogen burns invisibly to the human eye [1]. It must be approached with caution lest one get burned. I have heard of a case where leaks detection consists of wiping pipes with a straw broom and noting if it bursts into flame.

This WSU post advocates for hydrogen's relative safety: https://web.archive.org/web/20210809163754/https://hydrogen....

1 https://www.crowcon.com/blog/the-dangers-of-hydrogen/

Perhaps such a setup could come with a system to inject a small amount of additives from a replaceable canister to give the flame color, and to give the gas an odor in case of leaks like they do with natural gas. I'm not chemist so I don't know if that's a possibility with hydrogen.

It seems that freshwater pumped water storage could be one of the most cost-effective options especially paired with batteries for peaking. Adding it to the analysis would be useful.

But there are very limited places you can put that. It needs a suitably shaped mountain.

PWS is great but not scaleable. https://www.quidnetenergy.com/solution/ is one possible scaleable alternative that I haven't been able to crunch numbers on (the website details are scarce)

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