Submitted by alex20_202020 t3_yobd6l in Futurology
The_RealKeyserSoze t1_ivdybmt wrote
Reply to comment by vVWARLOCKVv in Dutch pilot project for hydrogen heated homes allowed to begin by alex20_202020
Most hydrogen made now comes from natural gas, but you can make it from water using clean energy sources. And when you burn it you get water not CO2.
So it is much cleaner than natural gas. The challenge is distribution. Hydrogen leaks out of everything and makes metal brittle/weak. It’s generally just a huge pain to work with. Also round trip efficiency is low at maybe 70%, so you need more energy to produce the hydrogen than you get out of it as heat. Which means it will likely cost more than natural gas, but if you factor in externalities (air pollution deaths/damages, climate change, etc) it is likely cheaper than natural gas.
Another option is heat pumps, which run on electricity (easy to distribute/can be clean) and achieve ~300% efficiency by moving rather than producing heat. Their main drawback is high fixed cost of installation.
Bewaretheicespiders t1_ivfpv6q wrote
>but you can make it from water using clean energy sources.
Which is incredibly dumb when you could be heating the house directly with those energy sources instead of the huge loss, cost and safety issue to turn it into hydrogen.
cyberFluke t1_ivgl8yu wrote
Hydrogen is just acting as the battery in this case.
It comes down to how economically hydrogen can be stored and moved compared to storing the electricity directly.
You're right at a physics level, but the economics of energy storage might play out differently.
Bewaretheicespiders t1_ivgooew wrote
Terrible for storage, both long term because of the leaks and boiloff, and on the short term because of the conversion losses. This is just a way to keep europe dependant on gas without calling it gas.
The_RealKeyserSoze t1_ivi36fe wrote
Its easier to move electricity than hydrogen. So hydrogen would have to make sense due to storage, for cars/transport it clearly does make sense. For heating idk, the low round trip efficiency of hydrogen would likely favor heat pumps running on electricity instead.
CriticalUnit t1_ivf1l6y wrote
> And when you burn it you get water not CO2.
But you do still get NOx emissions....
The_RealKeyserSoze t1_ivh9z09 wrote
That’s true, but its still a massive improvement compared to what we currently use (oil and gas). Heat pumps would be ideal.
CriticalUnit t1_ivj33ow wrote
Sure green hydrogen is better than what we currently use in terms of emissions. The problem is that it's not the best option available to replace what we currently use.
Omateido t1_ivfay6m wrote
From burning H2?
realityChemist t1_ivfg3ij wrote
Yes.
If you burn hydrogen in pure oxygen you won't get any, but typically we burn things in air. Air is about 78% nitrogen, and even though N2 is pretty damn unreactive when you have so much of it hanging around in a hot flame, some of it will get oxidized. The hotter the flame, the more you get (and hydrogen burns very hot).
My understanding is that you can burn H2 with about 2x the theoretically required amount of air to reduce the amount of NOx emitted to basically nothing, but that's also going to reduce the efficiency of your boiler, so it's a tradeoff.
MilkshakeBoy78 t1_ivfc0aq wrote
h2o, is 2 hydrogens and one oxygen. doesn't h2o becoming hydrogen just split the hydrogen and oxygen. how is nitrogen or no emitted?
CriticalUnit t1_ivixq7f wrote
beauty_secret_keeper t1_iwu5yeh wrote
lol i thought you mentioned another cleanenergygroup firstly
And yes, this is proven information, I can sign up for this (:
[deleted] t1_ivetm1a wrote
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[deleted] t1_ivf3wgr wrote
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The_RealKeyserSoze t1_ivhaa4n wrote
Hydrogen can be produced from the electrolysis of water (which can be powered by any electricity source, ideally renewables). It can also be thermochemically produced from water potentially with thermal energy from nuclear power plants but that is not currently done.
Neither method requires any natural gas or direct CO2 emissions.
[deleted] t1_ivi88bq wrote
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The_RealKeyserSoze t1_iviis0n wrote
You said you “need to get the H from natural gas” which just isn’t true. And I think I stated that hydrogen is not particularly efficient. Heat pumps are better but hydrogen still has the potential to be clean.
[deleted] t1_ivjharu wrote
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The_RealKeyserSoze t1_ivji9cl wrote
It certainly doesn’t seem like that, especially since I had already addressed it. There is a bit more nuance to it and I tried to mention all of the pros and cons.
[deleted] t1_ivjieqp wrote
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The_RealKeyserSoze t1_ivjj78u wrote
Perhaps you should read my original comment again or even the section you originally quoted as I did not “ignore” the problem you refer to.
And it is clear from your follow up that you still don’t understand the situation.
>”If you then use the H2 to produce electricity, you're just wasting 20% of the electricity.”
This is about using H2 to produce heat, not electricity. There is a very big difference.
>”And solar and wind are very clearly not up to that task.”
Citation needed.
[deleted] t1_ivnjbur wrote
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The_RealKeyserSoze t1_ivo2x21 wrote
No one is talking about making electricity with H2, read.
[deleted] t1_ivqauuv wrote
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[deleted] t1_ivfgc83 wrote
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DonQuixBalls t1_ivg3ki6 wrote
If you have the power, just use it to heat the homes. Extra steps are waste.
cyberFluke t1_ivgll92 wrote
Storing the power however isn't as simple. Hence converting energy to hydrogen and storing that. Maybe. That's the point of the pilot projects, to see how the economics could scale for storage.
HardCounter t1_ivekakd wrote
Heat pumps are generally not good in extreme temperatures either, unless i'm mistaken. If there's practically no warm air outside to draw from they're not going to get much. It's best in well above freezing temperatures. Probably shorts weather in Denmark.
The_RealKeyserSoze t1_ivesv2b wrote
They work just fine in cold environment and there was a recent paper in Nature that found heat pumps already outperform current methods of heating using existing electricity mix for 95% of the worlds demand. They are so efficient that they can outperform oil/gas when electric grids are still running on a majority oil/gas.
HardCounter t1_ivgtmlp wrote
I guess people saw the link and didn't bother to check it because it doesn't say that at all. This paper relates to direct emissions. It's behind a paywall and says only this in the abstract, portions of which are utter bullshit and relate only to emissions:
> The electrification of passenger road transport and household heating features prominently in current and planned policy frameworks to achieve greenhouse gas emissions reduction targets. However, since electricity generation involves using fossil fuels, it is not established where and when the replacement of fossil-fuel-based technologies by electric cars and heat pumps can effectively reduce overall emissions. Could electrification policies backfire by promoting their diffusion before electricity is decarbonized? Here we analyse current and future emissions trade-offs in 59 world regions with heterogeneous households, by combining forward-looking integrated assessment model simulations with bottom-up life-cycle assessments. We show that already under current carbon intensities of electricity generation, electric cars and heat pumps are less emission intensive than fossil-fuel-based alternatives in 53 world regions, representing 95% of the global transport and heating demand. Even if future end-use electrification is not matched by rapid power-sector decarbonization, it will probably reduce emissions in almost all world regions.
Let me highlight a part
> We show that already under current carbon intensities of electricity generation, electric cars and heat pumps are less emission intensive than fossil-fuel-based alternatives in 53 world regions, representing 95% of the global transport and heating demand.
The_RealKeyserSoze t1_ivh9spv wrote
Not sure which portions you think are “utter bullshit” but here is a link to the full text. If you have your own source you could provide it, but Nature is not known for publishing “utter bullshit”.
And carbon emissions was the metric I was using for the comparison, if I didn’t make that clear. In terms of carbon emissions heat pumps are lower emission than current sources of heating (mainly gas and oil) and that will only improve as electric grids gain higher proportions of clean energy.
[deleted] t1_ivhcprs wrote
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The_RealKeyserSoze t1_ivhdtp3 wrote
>”They do not work in freezing temperatures.”
They do work in freezing temperatures. In fact you have a heat pump working in your freezer right now. You seem to have just made up this false claim and are now claiming Nature is not a credible source ???
In order for heat pumps to beat current heating sources in terms of emissions they have to function and still be very efficient.
>”They didn't used to be, but what gets published in many journals lately is highly politicized. I'm certain they would not publish an equally valid study that says something different when accounting for more factors. It's a bit off topic but: everything is agenda driven in the world right now because that's where the money is and it's seriously affecting scientific honesty. If nobody gets published for a study discrediting a certain idea then nobody is going to do that study, and even if they did nobody would believe it and/or be aware of it because it wasn't published.”
Source? Sounds like you got lost on your way to r/conspiracy
Derkxxx t1_ivets4i wrote
Netherlands is not a country of extreme weather, it is very temperate. Mild summers, mild winters. Mostly just very wet and quite windy. Besides that, heat pumps generally have an option to heat additionally electrically or in a hybrid system with natural gas if more heat is needed. Great thing about heat pumps is that they can cool as well through ventilation.
HardCounter t1_ivgqzib wrote
> Besides that, heat pumps generally have an option to heat additionally electrically or in a hybrid system with natural gas if more heat is needed.
This portion is a heater, not a heat pump. The statement i'm responding to was about heat pumps, not heaters.
pichael288 t1_ivf4344 wrote
Sort of. But it doesn't have to be well above freezing, it just has to be above freezing. And even they they make ones with a heating element that will function in colder weather.
HardCounter t1_ivgu3y2 wrote
The energy loss in greater temperature differentials is very high. Sure, if it's 40 degrees outside and you set your thermostate to 43 you're going to get a good return, but you probably want it nearer to the 60s or 70s and that's where they get you.
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