Hydrogen matters

[88V8]

Second National Infrastructure Assessment has been released, the headline is ....
This table explains their reasoning, although some will contest the numbers :

I wonder if the heat pump figure includes typical necessary changes to an existing CH system. Doubt it.

Given we can't even maintain a national pipe network that reliably holds water, I wonder in any case whether we could do so for hydrogen.

Unsurprising that Sunak has pushed back the gas boiler deadline.

V8

[Hallucigenia]

I wonder if the heat pump figure includes typical necessary changes to an existing CH system. Doubt it.

They have a technical annex that goes into hydrogen heating in more detail (annoyingly it seems you can't copy directly from it), on p10 it says the costs include "transition costs" such as radiator replacements, although high-temperature heat pumps get round for the need for the latter and in the real world they don't see much of a hit to efficiency as the high-temperature-ness is seldom needed in the UK, even up North.

Their main argument is that there's a few edge cases where hydrogen looks better in 2035 (assuming retail hydrogen costs are about the same in p/kWh as electricity), but those few cases are not worth the cost of maintaining a whole pipeline network for domestic use.

[TUK020]

I wonder if the heat pump figure includes typical necessary changes to an existing CH system. Doubt it.

They have a technical annex that goes into hydrogen heating in more detail (annoyingly it seems you can't copy directly from it), on p10 it says the costs include "transition costs" such as radiator replacements, although high-temperature heat pumps get round for the need for the latter and in the real world they don't see much of a hit to efficiency as the high-temperature-ness is seldom needed in the UK, even up North.

Their main argument is that there's a few edge cases where hydrogen looks better in 2035 (assuming retail hydrogen costs are about the same in p/kWh as electricity), but those few cases are not worth the cost of maintaining a whole pipeline network for domestic use.

Are "High Temperature Heat Pumps" ones that use a different refridgerant? I have read that existing heat pumps tend to generate flow temperatures of around 55C, which can be a problem with radiator systems that are designed for 65C, and that 55C is not high enough for hot water tank storage (which really should be >60C on recommendations for legionella). However, newer Ammonia based refridgerant systems generate higher flow temps of around 65C.
Is this correct?

[Hallucigenia]

They have a technical annex that goes into hydrogen heating in more detail (annoyingly it seems you can't copy directly from it), on p10 it says the costs include "transition costs" such as radiator replacements, although high-temperature heat pumps get round for the need for the latter and in the real world they don't see much of a hit to efficiency as the high-temperature-ness is seldom needed in the UK, even up North.

Their main argument is that there's a few edge cases where hydrogen looks better in 2035 (assuming retail hydrogen costs are about the same in p/kWh as electricity), but those few cases are not worth the cost of maintaining a whole pipeline network for domestic use.

Are "High Temperature Heat Pumps" ones that use a different refridgerant? I have read that existing heat pumps tend to generate flow temperatures of around 55C, which can be a problem with radiator systems that are designed for 65C, and that 55C is not high enough for hot water tank storage (which really should be >60C on recommendations for legionella). However, newer Ammonia based refridgerant systems generate higher flow temps of around 65C.
Is this correct?

Ammonia-based heat pumps are capable of much higher temperatures, but are more for industrial purposes, for domestic purposes it tends to be propane which doesn't go as high but is good enough, and is already found in houses as Calor Gas whereas ammonia introduces a whole new lot of safety concerns.

[TUK020]

Are "High Temperature Heat Pumps" ones that use a different refridgerant? I have read that existing heat pumps tend to generate flow temperatures of around 55C, which can be a problem with radiator systems that are designed for 65C, and that 55C is not high enough for hot water tank storage (which really should be >60C on recommendations for legionella). However, newer Ammonia based refridgerant systems generate higher flow temps of around 65C.
Is this correct?

Ammonia-based heat pumps are capable of much higher temperatures, but are more for industrial purposes, for domestic purposes it tends to be propane which doesn't go as high but is good enough, and is already found in houses as Calor Gas whereas ammonia introduces a whole new lot of safety concerns.

Any reason why these aren't widespread already? I see lots of media reference to cost of replacing radiators etc, but this would seem to be a problem already sorted?

[Hallucigenia]

Any reason why these aren't widespread already? I see lots of media reference to cost of replacing radiators etc, but this would seem to be a problem already sorted?

They're somewhat more expensive to buy, are somewhat less efficient when operating in high-temperature mode (but that's not often), and are relatively new on the market (1-2 years in the UK?) so some people just haven't heard of them, but if you see media claiming the radiator thing without even mentioning high-temperature heatpumps as a possible solution (which may not necessarily be appropriate in every case) then you know it's either ignorance or propaganda. There's a lot of it about, particularly in some newspapers....

[GrahamPlatt]

Couple of interesting things

Chinese firm proposing to build grid-scale solar-green-hydrogen plants in India

https://energy.economictimes.indiatimes ... /105336589

Germany building European-interconnector hydrogen pipeline

https://www.hydrogeninsight.com/policy/ ... -1-1554455

[GrahamPlatt]

Excellent discussion with chemical engineer, expert in the field of hydrogen. Long (1hr 20min) and really very negative on the future of a “hydrogen economy” ever being either commercially or ecologically feasible. Shame really, but there you go.

https://www.thegreatsimplification.com/ ... aul-martin

[GoSeigen]

Excellent discussion with chemical engineer, expert in the field of hydrogen. Long (1hr 20min) and really very negative on the future of a “hydrogen economy” ever being either commercially or ecologically feasible. Shame really, but there you go.

https://www.thegreatsimplification.com/ ... aul-martin

Thanks for the link. I don't know about "a shame", he's stating the bleeding obvious isn't he? I think the shame is on the people who either ignorantly or dishonestly push hydrogen as some kind of solution.


GS

[88V8]

Excellent discussion with chemical engineer, expert in the field of hydrogen. Long (1hr 20min) and really very negative on the future of a “hydrogen economy” ever being either commercially or ecologically feasible.

Thanks for the link. I don't know about "a shame", he's stating the bleeding obvious isn't he? I think the shame is on the people who either ignorantly or dishonestly push hydrogen as some kind of solution.

I'm sure think it has local application, within a plant or a limited area, such as the touted project at Grangemouth which must now be in doubt.
But the notion of a hydrogen grid or widespread domestic use is just bollox.

V8

[JohnB]

Beware the government's hydrogen strategy. It focuses on the harmful "blue" hydrogen, and wilfully underestimates it climate damage because of bad assumptions about leaks and atmospheric dwell times. Its designed to help the fossil fuel lobby.

https://www.theguardian.com/commentisfr ... ate-crisis

[JohnB]

Guardian Mythbusting piece on Hydrogen cars. TLDR - not going to happen



https://www.theguardian.com/business/20 ... ssion-cars

[BullDog]

Meanwhile, after decades of under investment, Stanlow Oil refinery looks set to have significant investment as a hydrogen industrial hub in North West England.

Very welcome indeed since UK is steadily losing refinery capability in favour of even more imported road fuels. Link -

https://eethydrogen.com/

[GrahamPlatt]

Producing Hydrogen from Iron-rich Rocks (without producing carbon dioxide).

https://www.sflorg.com/2024/03/es03042401.html

[tjh290633]

Producing Hydrogen from Iron-rich Rocks (without producing carbon dioxide).

https://www.sflorg.com/2024/03/es03042401.html

My first employer in 1957 had the steam-iron process for producing hydrogen in their catalogue. Used to fill barrage balloons during the war, it was a cyclic process with an initial heating process using producer gas, followed by a reaction process when stem was blown through the bed of heated iron.

Needless to say, it did evolve carbon dioxide in the initial blow cycle.

TJH

[AJC5001]

Producing Hydrogen from Iron-rich Rocks (without producing carbon dioxide).

https://www.sflorg.com/2024/03/es03042401.html

Shouldn't that be 'Producing Hydrogen from water by oxidation of iron', as my simplistic recall of schoolboy chemistry tells me?
The rocks don't contain any hydrogen, do they?

Isn't 'Producing Hydrogen from water by electrolysis' a better alternative?

Adrian

[GrahamPlatt]

Producing Hydrogen from Iron-rich Rocks (without producing carbon dioxide).

https://www.sflorg.com/2024/03/es03042401.html

Shouldn't that be 'Producing Hydrogen from water by oxidation of iron', as my simplistic recall of schoolboy chemistry tells me?
The rocks don't contain any hydrogen, do they?

Isn't 'Producing Hydrogen from water by electrolysis' a better alternative?

Adrian

Take your point, though it doesn’t seem to be “schoolboy” chemistry they’re working with here.

https://en.m.wikipedia.org/wiki/Serpentinization

And there may be additional benefits frm exctracting the heat generated (though if catalysed, this may be lower).

“The reaction is highly exothermic, releasing up to 40 kilojoules (9.6 kcal) per mole of water reacting with the rock, and rock temperatures can be raised by about 260 °C (500 °F),[9][10] providing an energy source for formation of non-volcanic hydrothermal vents.[11] The hydrogen, methane, and hydrogen sulfide produced during serpentinization are released at these vents and provide energy sources for deep sea chemotroph microorganisms”