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Cheap, sustainable hydrogen through solar power

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Re: Cheap, sustainable hydrogen through solar power

#61

Post by yummypaint »

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?

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 setup and sell excess back to the grid, that carbon reduction will be larger than if you used the same energy to inefficiently synthesize fuel.

Re: Cheap, sustainable hydrogen through solar power

#62

Post by michpoch »

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?

I think the closest to what you need would be some sort of pico hydro with pumped storage.

Re: Cheap, sustainable hydrogen through solar power

#63

Post by pkphilip »

miahi wrote: post #29
35mm wrote: post #26

Earlier quoted context omitted.

This is currently the Lavo hydrogen electrolysis product for home use [1] However the storage tanks are quite small. I would prefer if they made the hydrogen production and storage separate, so you could save up hydrogen in the summer to use in the winter. [1] https://www.lavo.com.au/

Hydrogen storage is not something that you really want to do at home, especially in "saving up" quantities. It is quite happy to explode, you need tremendous pressures and low temperatures for efficient storage, and also hard to contain (many "normal" materials are permeable to hydrogen). [1] [1] https://en.wikipedia.org/wiki/Hydrogen_safety

There are ways of storing hydrogen in metal hydrides at room temperature and pressure. This makes a LOT of sense for people who may want to have an option of buying stored energy - such as those who live in apartments without access to the terraces where solar panels can be deployed.

If these metal hydride storage is used similar to how changeable batteries are used, it is conceivable that you could drive up to a place like a fuel station just to change out your metal hydride storage in a matter of a couple of minutes and perhaps even get additional supplementary units packed at the back of the vehicle if they intend to go on a long journey.

https://www.frontiersin.org/articles/10.3389/fenrg.2021.6161...

There has also been recent advances in using Boron Nitride for storage - a perfectly safe chemical.

https://www.geelongmanufacturingcouncil.com.au/2022/07/innov...

Re: Cheap, sustainable hydrogen through solar power

#64

Post by theshrike79 »

_hypx wrote: post #55
theshrike79 wrote: post #35

Earlier quoted context omitted.

Synthetic fuels can be created with electricity. But, again, the efficiency is laughable. The amount of energy lost in the conversion is so huge that it's not viable unless you've got crazy levels of overproduction. But my comparison was about the fact that petrol engines convert only 20-30% of the energy in the fuel to actual motion - everything else is lost in friction and output as heat. Toyota had a prototype eng…

Fuel cell vehicles also use electric motors. They will not lose to combustion engines on efficiency. You seem to contradict yourself on how you think hydrogen vehicles work.

Fuel cell vehicles sill need hydrogen to generate the electricity.

Hyrdogen has about 80% losses from electricity to wheels. When 55kWh of electricity is used to generate hydrogen and that is used in a Toyota Mirai to move the car, only 11kWh ends up at the wheels.

If you do that same with a Hyundai Ioniq 5, all 55kWh (minus some transfer losses) get to the wheels.

Re: Cheap, sustainable hydrogen through solar power

#65

Post by pfdietz »

If I understand correctly, this is producing hydrogen and oxygen mixed together. This is useless. It's also overall less efficient that commercial PV cells driving commercial electrolysers.

One common issue with all these concepts doing electrolysis at the collector is how do you gather the hydrogen. Rigging PV modules together with wires is much more practical than hooking hydrogen emitters together with tubing or pipes.

Re: Cheap, sustainable hydrogen through solar power

#66

Post by midasuni »

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?

Re: Cheap, sustainable hydrogen through solar power

#67

Post by defrost »

pkphilip wrote: post #63
miahi wrote: post #29

Earlier quoted context omitted.

Hydrogen storage is not something that you really want to do at home, especially in "saving up" quantities. It is quite happy to explode, you need tremendous pressures and low temperatures for efficient storage, and also hard to contain (many "normal" materials are permeable to hydrogen). [1] [1] https://en.wikipedia.org/wiki/Hydrogen_safety

There are ways of storing hydrogen in metal hydrides at room temperature and pressure. This makes a LOT of sense for people who may want to have an option of buying stored energy - such as those who live in apartments without access to the terraces where solar panels can be deployed. If these metal hydride storage is used similar to how changeable batteries are used, it is conceivable that you could drive up to a pla…

There is a case for portable storage, sure.

Hydrogen at scale is going to look more like a means to export sunlight energy from equatorial climes (Australia, Sahel, etc) to Europe, the northern US, Canada as required.

Efficiencies dictate the most likely roll out is large central generation of electricity and dispersal via the existing electrical grid system.

In a similar view individual per apartment solar panels make little sense, panels should be built into entire buildings .. across roofs and across any required parking structures, etc.

Re: Cheap, sustainable hydrogen through solar power

#68

Post by cduzz »

yummypaint wrote: post #61
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?

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, though, that stuff's tough. I think 99% of Hydrogen advocates don't understand just how nasty the stuff is.

Re: Cheap, sustainable hydrogen through solar power

#69

Post by api »

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?

A composter costs very little and can product a decent amount of methane.

Animals like goats and pigs can produce a lot of dung that will turbocharge that quite a bit.

A little searching yields stuff like: https://www.motherearthnews.com/sustainable-living/renewable...

The low tech route is far cheaper and easier at small scale if you want to make combustible fuel.

Re: Cheap, sustainable hydrogen through solar power

#70

Post by noogle »

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?

This will last less than a day.

What to do in the winter? If the answer is "use the grid", then we just kick the can to someone else, who will probably use fossil fuels to provide the energy. The basic problem remains - solar/wind are intermittent and fluctuating.

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