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Cheap, sustainable hydrogen through solar power

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Re: Cheap, sustainable hydrogen through solar power

#71

Post by blisterpeanuts »

cduzz wrote: post #68
yummypaint wrote: post #61

Earlier quoted context omitted.

You can effectively accomplish the same thing from an environmental perspective by running your house as efficiently as possible. If you already have home solar, you are reducing the amount of carbon put into the air by power plants. Since CO2 molecules are indistinguishable from each other, that carbon reduction could just as well have come from burning renewable synthetic fuel made at home. If you have a big solar…

You can't operate a car / tractor / hot air balloon with just an efficient house. Also, you can't run your house on an efficient house + solar over the 2-6 months the sun isn't in the right place (in the sky) for very long or when your panels are covered in snow for a week. An efficient house gets you to the table and is a multiplier, but long term energy storage is also really important for lots of people. Hydrogen,…

Interestingly, our solar panels seem to shed the snow pretty fast, in fact faster than the plain roof. I guess the black cells warm up in the sunlight and the snow just slides off them after a couple of days. Pre-solar, we used to have to rake the roof to prevent ice dams from building up, but no longer.

Re: Cheap, sustainable hydrogen through solar power

#72

Post by oezi »

cyri wrote: post #57

Impressive idea. Hope they get a better efficiency factor. On a side node, you can already add Hydrogen to your home. There is a startup in Berlin, DE which sells complete systems for home: solar roof, heat pump, electrolysis device, bottles and ventilation system. During summer you fill the bottles with H2 and during winter you consume it. I'm not affiliated with them. The price before Corona for the whole system wa…

Nice! So it seems demand is so high they can increase their prices.

Do you know what the capacity of a single system is? Could one unit be shared between multiple residential units?

Re: Cheap, sustainable hydrogen through solar power

#73

Post by brilee »

fbdab103 wrote: post #19

I am waiting for the day when there is an affordable ( Is anything like that on the horizon? Or do all of these liquid fuel synthesis options require industrial pressures/volumes/input electricity so as to forever be out of reach from residential synthesis?

Just use the grid, they can move energy through time a lot more efficiently than you can ever hope to do. https://www.moderndescartes.com/essays/factobattery/

Re: Cheap, sustainable hydrogen through solar power

#75

Post by makeitdouble »

kwhitefoot wrote: post #50

Unless you need hydrogen for a capability that only hydrogen has it is much more efficient to use solar electricity either directly or to charge batteries.

The bet seems to on the cost/tradeoffs of producing batteries vs producing hydrogen generators. If at some point producing hydrogen generators can become more affordable and sustainable than batteries (especially from countries will low rare earth resources) it would be a win for them.

Re: Cheap, sustainable hydrogen through solar power

#76

Post by ajross »

midasuni wrote: post #66
fbdab103 wrote: post #19

I am waiting for the day when there is an affordable ( Is anything like that on the horizon? Or do all of these liquid fuel synthesis options require industrial pressures/volumes/input electricity so as to forever be out of reach from residential synthesis?

Why not just a 20kWh battery for energy time shifting. Or are you looking to sell the hydrogen?

The commenter's goal is presumably season-shifting, which is two orders of magnitude off from feasible battery capacity. In most areas in the US, a full-roof solar system will produce enough energy in aggregate to power the home's use year-round, but there's no way to get all those summertime watt-hours into the lines in winter when the panels are dark.

But indeed, no, this just doesn't work. Best available efficiency for round-trip electrolytic fuel production / electricity generation is 40% or so, meaning that those roof panels wouldn't be enough anyway. (Also there's the problem of having every home store a winter's worth of pressurized hydrogen or whatever on-premises. Yikes.) It's not worth it.

Home solar is attractive because unlike most infrastructure it scales down really well and is actually feasible to do at the level of an individual user. But, like most infrastructure, seasonal power management is a grid-wide problem and needs to be solved at the utility level. There are plenty of tricks available there that homeowners don't have access to.

Re: Cheap, sustainable hydrogen through solar power

#77

Post by DubiousPusher »

bamboozled wrote: post #37
DubiousPusher wrote: post #18

Is it just me or has it been like 18 months of one supposedly "game changing" hydrogen catalyst after another? I'm not trying to be cynical. It just seems the science press is awash in results from one research project after another in this area and I find it very difficult to rank which ones have any credible chance of utility.

I'm also sick of 18 months worth of negative comments about how hydrogen is a waste of time...

Agreed. I neither said that, nor think that.

Re: Cheap, sustainable hydrogen through solar power

#78

Post by natmaka »

brilee wrote: post #73
fbdab103 wrote: post #19

I am waiting for the day when there is an affordable ( Is anything like that on the horizon? Or do all of these liquid fuel synthesis options require industrial pressures/volumes/input electricity so as to forever be out of reach from residential synthesis?

Just use the grid, they can move energy through time a lot more efficiently than you can ever hope to do. https://www.moderndescartes.com/essays/factobattery/

Even the grid's may benefit from green hydrogen, without any major overhaul: https://www.ge.com/gas-power/future-of-energy/hydrogen-fuele...

Also conceptually related (small-scale): https://news.ycombinator.com/item?id=32694644

Re: Cheap, sustainable hydrogen through solar power

#79

Post by kseistrup »

fbdab103 wrote: post #19

I am waiting for the day when there is an affordable ( Is anything like that on the horizon? Or do all of these liquid fuel synthesis options require industrial pressures/volumes/input electricity so as to forever be out of reach from residential synthesis?

There are also things like MAGFLY that stores electricity (from e.g. solar panels) as kinetic energy in flywheels:

- https://www.flywheel.dk/

- https://wattsuppower.com/flywheel/

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