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Cheap, green hydrogen would be a breakthrough in clean energy

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Re: Cheap, green hydrogen would be a breakthrough in clean energy

#221

Post by p_l »

japanuspus wrote: post #210
Barraketh wrote: post #52

Ammonia has been mentioned a few times in this thread, but I will expand a bit, because I believe it is the most promising hydrogen-based approach. Essentially, the idea is to use ammonia directly as fuel. There is an ARPA-E funded project (that I'm currently failing to find) that cracks ammonia into hydrogen and nitrogen using heat. They claim that they can create a mixture of H2 and ammonia that will burn at any re…

Just wanted to add some basic chemistry information as background Hydrogen (H) can be split from water (H2O) with a by-product of Oxygen (O). Hydrogen is hard to handle logistically (as discussed elsewhere in the thread), and the real idea in "Power to X" is to include Hydrogen in another molecule with better logistics. Main contenders are Ethanol (C2H5OH, alcohol), Methane (CH4, ~natural gas), and Ammonia (NH3). Eth…

Interestingly enough, at least in USA the proposed automotive hydrogen solution is one that reduces logistical problems by placing electrolysis equipment at filling stations - then you have reduced transport to just on-site piping and storage tank, and it makes sense to colocate charging of electric cars with hydrogen ones, as well as use demand-response for the stations (providing extra load balancing for the energy grid, which benefits renewables and nuclear alike)

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#222

Post by yvdriess »

midasuni wrote: post #187
beambot wrote: post #176

Earlier quoted context omitted.

For heating, you are probably better off converting to electricity (burning or fuel cell) and driving a high-COP heat pump. Good heat pumps are ~250-300% "efficient" at "converting" electricity to heat. (Efficiency isn't in the Carnot sense, and heat pumps move heat rather than generating heat... Semantics, but point stands.) For example: I recall reading that it is more efficient (ie BTUs generated) to use natural g…

A modern heat pump claims a cop in the 4.8 range It’s more efficient to burn the gas in a grid power station, convert to electricity, and use the electricity to drive the heat pump, then it is to burn the gas for heat directly.

Watch out, cop ranges wildly (1.1-5+) depending on the type of heat pump, output temperature and intake temperature. Ideal are water-water heat pumps connected to a deep well, but these cannot be installed everywhere and carry a significant (roughly double) capital investment. Air-water heat pumps are very sensitive to outside air temperature and output temperature. Low-temperature heating (30-40C) still gets an OK ~2-2.5 cop in freezing temperatures, but sanitary water (65deg C) tanks the efficiency significantly.

Another consideration is that you lose efficiency in converting chemical to electrical energy, plus there is a higher transport and distribution loss to factor in.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#223

Post by ClumsyPilot »

ZeroGravitas wrote: post #213
ClumsyPilot wrote: post #209

Earlier quoted context omitted.

Ammonia production is already in billions of dollars, we produce 191 million tonnes What is the basis in physics for your belief that ammonia can be produced more efficieblntly, and why was it not done already?

Because it piggybacks on the political might of fossil fuel producers who are subsidized by taxpayers and don't have to pay for their externalities. It's not "cheaper" for a mob connected waste disposal firm to dump waste into a river. If they were prosecuted for the damage they did to other people's property and had to pay for the damage they did then they'd need to raise their prices to the point that just dealing…

So whats the best case possible efficiency?

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#225

Post by typhonic »

In 1973 I visited the office of a chemistry professor. He and his research partner seemed to be on somewhat of a downhill slide. For years they had dreams of discovering a catalyst that would let water break into hydrogen and oxygen from exposure to direct sunlight. They never found that catalyst, and after nearly fifty years, I never even hear the concept any more.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#226

Post by breadloaf »

simonebrunozzi wrote: post #196
ggm wrote: post #147

The FF industry is leaping (has leapt, historically) on CCS as a getout clause and has sunk french metric tonnes of money into CCS. So far, its uneconomic except for the specific use of pumping gas into wells to make them more productive, which leads to more fugitive gas. No significant CCS experiment worldwide has achieved its goals as sequestration. The one in Western Australia releases so much CO2 it has to pay a…

CCS = Carbon Capture and Storage You should clarify what an acronym means before using it tens of times.

I was honestly thinking that he is talking about CCS fleet gas pay cards.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#227

Post by taneq »

typhonic wrote: post #225

In 1973 I visited the office of a chemistry professor. He and his research partner seemed to be on somewhat of a downhill slide. For years they had dreams of discovering a catalyst that would let water break into hydrogen and oxygen from exposure to direct sunlight. They never found that catalyst, and after nearly fifty years, I never even hear the concept any more.

Looks like it's still an active area of research (the catalyst bit, not necessarily the sunlight bit): https://www.chemistryworld.com/news/ideal-water-splitting-ca...

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#228

Post by taneq »

clouddrover wrote: post #104
craig1f wrote: post #2

It would. Yet there is no promising tech in this field. Hydrogen is supported only to draw support away from EVs. If hydrogen becomes inexpensive to produce, it will by by way of solar power used to generate it. It will never be easy to store. Hydrogen is the smallest element, and can move through solid objects over time. It is violently explosive. You think these EV fires you see all the time are bad? They're nothin…

> Hydrogen is supported only to draw support away from EVs. I always find this false hydrogen versus batteries narrative bizarre. Hydrogen fuel cell vehicles are EVs. It isn't an exclusive choice between hydrogen or batteries. Choose both hydrogen and batteries, both FCEVs and BEVs. In any case, if you want your EV to be manufactured with green steel then you want hydrogen to be used in the production of that steel:…

The hydrogen-is-the-enemy-of-EVs thing comes from the way that car manufacturers in the '90s pushed hydrogen as the "fuel of the future" in order to stall the CARB EV mandate from interfering with their ICE car sales. It was a cynical bait-and-switch where they simultaneously insisted that it was impossible to build acceptable BEVs (despite both the GM EV1 and the Rav4-EV being universally lauded) and extolled hydrogen fuel cell EVs as the Bright New Future that was "only 10 years away". This let them continue business as usual in exchange for the occasional puff piece on hydrogen.

If they hadn't been allowed to get away with it, we'd have had practical EVs by 2000 instead of having to wait another decade for Tesla.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#229

Post by Retric »

anovikov wrote: post #220
Retric wrote: post #212

Earlier quoted context omitted.

Most of that is 25GW is recent and cheap PV at close to $0.02 per watt. It’s the tiny fraction from before 2015 that was really expensive. A 250m subsidy to grid solar right now would easily increase total installed solar to 100GW+. So, I wouldn’t be surprised if that project alone was a larger subsidy than every subsidy given to grid solar in Australia.

$0.02 per watt??? don't you confuse with the cost of kilowatt-hour of power? Cheapest installed solar is >$1 per watt, most of the time about $1.5-$2 per watt. Cheapest Chinese panels themselves are about $0.25 per watt and they make a tiny part of the overall setup costs.

Loans.

Nobody is going to hand out a subsidy and say here buy panels with this. It’s all about the multiplier, even home subsidies don’t 1:1 pay for panels it’s at best deduct the cost from your taxes saving 30% or whatever on the cost and often less than that.

So, that’s where the ~2c/kWh shows up it’s roughly the minimum cash on hand someone needs to get the ball rolling for loans on a grid solar project assuming a proven track record. Now hand someone with that track record 250 million free and clear and not only can they get loans but they can also attract private investors.

Of course the risk is you hand out money to projects that would happen either way and get noting for the subsidy.

Re: Cheap, green hydrogen would be a breakthrough in clean energy

#230

Post by kkfx »

ncmncm wrote: post #218
kkfx wrote: post #208

Earlier quoted context omitted.

Let's made a game: how much electricity in kWh you need to extract a liter / gallon of H₂? How fast H₂ leak from a generic tank/in what form you propose to contain it and how much energy such form demand. With this data we can discuss scalability.

Let's make a game: you collect actual figures instead of just making shit up.

Ok, from a conference not much time ago I've noted, but unfortunately fail to recover linkable reference, around 67kWh to extract 1kg of H₂ if there are no losses in the process. I can't estimate losses but I can imaging are there in a relatively relevant percentage. The there is the storage issue: H₂ goes trough essentially any tank, no matter how we store it in practical ways, and that's another loss hard to be computed but there.

I've found this old report https://www.nrel.gov/docs/fy04osti/36734.pdf and I doubt we really have made significant advance since it.

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