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Hydrogen production is almost entirely produced from fossil fuels currently. Its not really a low carbon energy source unless electrolysis can be made much mor

Hydrogen production is almost entirely produced from fossil fuels currently. Its not really a low carbon energy source unless electrolysis can be made much more efficient. Its a shame this article didn't examine the production side of hydrogen.

helsinkiandrew 6y ago
Isn’t the last 1/3 of the article about the differences between grey, blue and green hydrogen?
- admax88q 6y ago
  Ah that's my fault then. About 2/3 of the way through the article something loaded or shifted as nobody can resist the urge to highjack scrolling and I lost the rest of the text so I stopped reading.
ced 6y ago
From Wikipedia: The lower the energy used by a generator, the higher its efficiency would be; a 100%-efficient electrolyser would consume 39.4 kilowatt-hours per kilogram (142 MJ/kg) of hydrogen,[24] 12,749 joules per litre (12.75 MJ/m3). Practical electrolysis (using a rotating electrolyser at 15 bar pressure) may consume 50 kW⋅h/kg (180 MJ/kg), and a further 15 kW⋅h (54 MJ) if the hydrogen is compressed for use in hydrogen cars. It's not great, but it doesn't seem unworkable. I can't read the article, but isn't the idea to use hydrogen tanks as a battery to smooth out the variability of renewables like solar?
DaiPlusPlus 6y ago
How is that different from criticism of BEVs when they’re used in areas with coal-based electricity?
- admax88q 6y ago
  My understanding is moving electricity into a battery is much more efficient than using it to break water into hydrogen.
  - DaiPlusPlus 6y ago
    It’s an engineering-tradeoff. The efficiency losses in hydrogen production are offset by the ability to refuel a hydrogen tank in under a minute compared to the hours it takes to safely[1] recharge a BEV. Plus, if hydrogen fuel production is powered by environmentally friendly electricity then the efficiency losses should only worry people concerned about the heat-death of the universe (and it’s no worse than the 20% efficiency of an ICE engine. “Don’t let perfect be the enemy of good”, etc) [1] While Tesla’s V3 Superchargers are amazing in that charging stops can now be as short as 10-15 minutes to for 100+ miles of range - Superchargers should not be used for day-to-day charging because it wears out the battery too much (hence the hype over the new generation of Lithium cells, that “million-mile battery”, but for the rest of us using current-gen Lithium batteries (myself included, I drive a Tesla too) I don’t want to have to drop $20k+ for an out-of-warranty battery replacement).
hnick 6y ago
I don't think most people consider it an energy source, more so a battery or storage medium. And cheaper storage is an important part of the renewables story because local supply can be unpredictable. I saw this article earlier today along those lines: https://www.smh.com.au/environment/climate-change/alchemy-of-energy-breakthrough-offers-mass-hydrogen-storage-options-20200702-p558dj.html https://www.smh.com.au/environment/climate-change/alchemy-of... Supposedly this stores hydrogen metal hydrides cheaper than lithium batteries, whatever that means, but I'm not qualified to judge.
- dghughes 6y ago
  There is a video on YouTube about Bob Lazar the area 51 guy. Only it's about how he uses solar and wind to break down water into oxygen and hydrogen. He stores the hydrogen as a metal hydride. The tanks are heated to release the hydrogen and it's used to power his car.
goda90 6y ago
The article does talk about steam reforming vs steam reforming + carbon capture vs electrolysis of water and the carbon cost and economics of each.
reyoz 6y ago
A recent report [1] looked at the efficiencies of generating hydrogen at a waste water treatment plant to lower production costs. The WWTP provides the water and uses the oxygen that is also produced by electrolysis to increase the efficiency of the biological treatment process vs air. Some of the electricity for the electrolysis can also be sourced from biogas produced by the WWTP. [1] https://www.jacobs.com/sites/default/files/2020-06/jacobs-yarra-valley-water-towards-a-zero-carbon-future.pdf https://www.jacobs.com/sites/default/files/2020-06/jacobs-ya...

helsinkiandrew 6y ago

Isn’t the last 1/3 of the article about the differences between grey, blue and green hydrogen?

admax88q 6y ago
Ah that's my fault then. About 2/3 of the way through the article something loaded or shifted as nobody can resist the urge to highjack scrolling and I lost the rest of the text so I stopped reading.

ced 6y ago

From Wikipedia: The lower the energy used by a generator, the higher its efficiency would be; a 100%-efficient electrolyser would consume 39.4 kilowatt-hours per kilogram (142 MJ/kg) of hydrogen,[24] 12,749 joules per litre (12.75 MJ/m3). Practical electrolysis (using a rotating electrolyser at 15 bar pressure) may consume 50 kW⋅h/kg (180 MJ/kg), and a further 15 kW⋅h (54 MJ) if the hydrogen is compressed for use in hydrogen cars. It's not great, but it doesn't seem unworkable. I can't read the article, but isn't the idea to use hydrogen tanks as a battery to smooth out the variability of renewables like solar?

DaiPlusPlus 6y ago

How is that different from criticism of BEVs when they’re used in areas with coal-based electricity?

admax88q 6y ago
My understanding is moving electricity into a battery is much more efficient than using it to break water into hydrogen.
- DaiPlusPlus 6y ago
  It’s an engineering-tradeoff. The efficiency losses in hydrogen production are offset by the ability to refuel a hydrogen tank in under a minute compared to the hours it takes to safely[1] recharge a BEV. Plus, if hydrogen fuel production is powered by environmentally friendly electricity then the efficiency losses should only worry people concerned about the heat-death of the universe (and it’s no worse than the 20% efficiency of an ICE engine. “Don’t let perfect be the enemy of good”, etc) [1] While Tesla’s V3 Superchargers are amazing in that charging stops can now be as short as 10-15 minutes to for 100+ miles of range - Superchargers should not be used for day-to-day charging because it wears out the battery too much (hence the hype over the new generation of Lithium cells, that “million-mile battery”, but for the rest of us using current-gen Lithium batteries (myself included, I drive a Tesla too) I don’t want to have to drop $20k+ for an out-of-warranty battery replacement).

hnick 6y ago

I don't think most people consider it an energy source, more so a battery or storage medium. And cheaper storage is an important part of the renewables story because local supply can be unpredictable. I saw this article earlier today along those lines: https://www.smh.com.au/environment/climate-change/alchemy-of-energy-breakthrough-offers-mass-hydrogen-storage-options-20200702-p558dj.html https://www.smh.com.au/environment/climate-change/alchemy-of... Supposedly this stores hydrogen metal hydrides cheaper than lithium batteries, whatever that means, but I'm not qualified to judge.

dghughes 6y ago
There is a video on YouTube about Bob Lazar the area 51 guy. Only it's about how he uses solar and wind to break down water into oxygen and hydrogen. He stores the hydrogen as a metal hydride. The tanks are heated to release the hydrogen and it's used to power his car.

goda90 6y ago

The article does talk about steam reforming vs steam reforming + carbon capture vs electrolysis of water and the carbon cost and economics of each.

reyoz 6y ago

A recent report [1] looked at the efficiencies of generating hydrogen at a waste water treatment plant to lower production costs. The WWTP provides the water and uses the oxygen that is also produced by electrolysis to increase the efficiency of the biological treatment process vs air. Some of the electricity for the electrolysis can also be sourced from biogas produced by the WWTP. [1] https://www.jacobs.com/sites/default/files/2020-06/jacobs-yarra-valley-water-towards-a-zero-carbon-future.pdf https://www.jacobs.com/sites/default/files/2020-06/jacobs-ya...