Hydrogen power

[tom73]

Yet more green washing.

 

[albion]

Cynical me says that via the same statements the ocean is two thirds hydrogen. H2O

There is also talk of hydrogen mining with the, current inefficient, electrolysis using solar panels the best long term bet.

 

[FishFright]

Cynical me says that via the same statements the ocean is two thirds hydrogen. H2O

There is also talk of hydrogen mining with the, current inefficient, electrolysis using solar panels the best long term bet.

Using the electricity generated directly is an actual long term bet worth backing.

 

[Dadam]

Hydrogen is not energy dense by volume, quite the opposite - it needs compressing to huge pressure (700 atmospheres as above for cars) to make it dense enough.

True, I should have said by mass. The point was you take the source material (e.g water, hydrocarbons) and just extract the H2, you don't need to carry the rest (O2, C). IF you can find a way to carry it that's efficient in both mass and volume.

Problem is the level of compression needed to do that in a manageable package adds a lot of weight back, hence the CF cylinders.
Lots of safety concerns there, I wouldn't like to be near a cylinder of H2 (or anything) going bang at 700 bar!

 

[Dadam]

Cynical me says that via the same statements the ocean is two thirds hydrogen. H2O

There is also talk of hydrogen mining with the, current inefficient, electrolysis using solar panels the best long term bet.

By atomic weight it's 11% hydrogen. It's only 2/3 by volume when you split it into gases.

Using the electricity generated directly is an actual long term bet worth backing.

What do you mean? Thermodynamics = you never get back 100% of the energy you put in. Hydrogen isn't an energy source, it's an energy storage medium

 

[FishFright]

By atomic weight it's 11% hydrogen. It's only 2/3 by volume when you split it into gases.



What do you mean? Thermodynamics = you never get back 100% of the energy you put in. Hydrogen isn't an energy source, it's an energy storage medium

I was replying to the comment about using solar generated electricity to produce Hydrogen.

 

[wafter]

The elephant in the room that's always glossed over is who is going to build the hydrogen infrastructure?

The elephant on the room is that there are too many people and the consumptive lifestyle we've been up-sold by the establishment for their own ends uses an unsustainable amount of energy.

 

[Joffey]

We’ll all have electric cars by the time hydrogen cars enter the mass market with a realistic infrastructure to refuel.

I can see heavy plant machines, lorries, ships etc using it but I can’t envisage it making it onto our roads in meaningful numbers by 2050.

 

[presta]

Hydrogen's horrendously inefficient:

 

[the snail]

...

A lot of pieces need to fall into place to make this viable, but who knows?

The most important one being revising the laws of physics. It doesn't take long to realise that hydrogen is completely impractical for most transport applications when you look into the reality of it, for many reasons.

 

[cougie uk]

It's never going to be any thing more than a very small niche that's using hydrogen - no matter what the Dhaka Tribune says.

I can literally charge my car from my solar panels on the roof.

if I were to use hydrogen it would be a lot more faff with a huge supply chain and obviously everyone taking a cut at every stages so it's going to be hugely more expensive - that's even ignoring how inefficient the production is.

 

[albion]

Last weeks wind meant it felt like there was enough wind energy in our gardens to produce 12 months worth of electricty.
Storing it all in batteries is near enough impossible, thus hydrogen enters the equation.

I agree though, both hydrogen fuel cells and mixing it with north sea gas is not the way forward. Hydrogen power stations probably are.
Or just maybe we can get there by via wind overcapacity.

 

[geocycle]

There may be a limited case for hydrogen. I can see it being made during periods of low demand for energy, eg nuclear stations at night. Whether it makes it into cars I’m not sure. Ships or boilers perhaps?

 

[Profpointy]

The Toyota Mirai has carbon fibre tanks at 700 atmospheres. I wouldn't say that's dangerous per se, but it does present challenges.

To add a bit of perspective, steel SCUBA diving tanks are normally 232 bar / atmospheres. 300 Bar tanks are sold but for various reasons are, for most people, more trouble than their worth for diving. 700 bar is a lot !

 

[lazybloke]

Hydrogen's horrendously inefficient:

View attachment 720982

Hydrogen doesn't seem very relevant in a UK motoring forum; BEVs seem the near perfect solution for cars, and I'd estimate will achieve market penetration of circa 90% within 2-3 decades unless the deadlines are changed or some other technology comes along.
But one size doesn't fit all.


Consider all internal combustion engines in all applications; you can't simply replace them with motor and battery because energy for charging isn't available/reliable in all locations. Solar/wind helps plug the gap where there are no grid connections, but there will aways be a need for a high density energy source that can be easily refilled.

Likely internal combustion will persist, but hopefully with greener manufactured fuels.
Fuel cells powered by ammonia or methanol are expensive options; they get away from the pure hydrogen storage issue; or alternately there's the metal hydride storage solution for hydrogen, but that's even more expensive.
Niche applications.