How to Produce Green Hydrogen for $1/kg (2023)

[londons_explore]

When doing back of the envelope calculations like this, it is helpful to look at the raw materials cost that goes into the capex figures.

For example, in transformers there is a lot of steel and copper. You likely won't reduce their costs much unless you figure out how to build them with less steel and copper.

But in electrical inverters, there is only a little steel and copper, and the rest of the cost is in fairly specialized silicon, software, and high design costs. There big cost reductions are probably possible at scale - perhaps to just 1% of today's inverter costs.

Now remember that whatever you're building needs to compete not with today's system, but in a hypothetical future with those optimized inverters.

[marcosdumay]

Your 60Hz inverters will use about as much copper (or aluminum) and steel as a 60Hz transformer, or a 60Hz generator. How much of it you need is mostly determined by the frequency, voltage, and current it will handle.

What is another advantage for the people in the article, because they still need DC/DC converters, but they have complete liberty to pick its frequency.

[bryanlarsen]

According to the article, they are feeding the DC current straight from the solar panels to the electrolyzers. They don't need transformers.

[pfdietz]

Some transformers use aluminum instead of copper.

[ZeroGravitas]

Presumably this also applies to desalination and other energy intensive applications.

Basically, cheap solar combined with cheap capex equipment running 25% of the time can beat trying to run expensive capex equipment 24/7 once energy costs dominate the equation.

[londons_explore]

Note that this future, as well as requiring insane amounts of super cheap electricity, also requires someone to figure out cheap direct air capture of CO2. Nobody is even remotely close to that yet.

[icegreentea2]

For what it's worth, I think they (as in Terraform) intend to also tackle that part of the problem.

I think one advantage they have over current DAC approaches is that since they're going straight from their capture material into their methane reactor, they are both creating a valuable output from their carbon capture (where as most current systems need to add sequestration costs).

[marcosdumay]

There's a lot we can do with hydrogen alone. But yep, carbon capture from the air is very important.

[kkoste]

> Cheap direct air capture of CO2.

What is wrong with trees or algaes? Seems to me it doesn't get much cheaper than that.

[reducesuffering]

That is literally what Casey Handmer, author of the post, has a company working on, because he’s accurately projecting the exponential solar energy increases coming.

[dathinab]

One thing which frequently seems to be overlooked it that clean, preferable distilled, water is needed to fuel a hydrogen electrolyzer (the less clean the more issues when trying to electrolyze it).

Which has it's own monetary, energetic, and potential social cost. A potentially not so small cost, too. Depending on location and climate change.

[rini17]

On the contrary, distilled water is not conductive enough. You do need some ions in it. Inexpensive chemicals like sodium hydroxide/ bicarbonate also prevent limescale, avoid producing chlorine, etc...but then you end up with salty/alkaline brine. Which might be the true issue here, how to dispose of industrial quantities of that.

[Kirby64]

This is a whole heck of a lot of assumptions and hurdles they’ve described to get anywhere close to that $1/kg price… I wish them well, but 2027 isn’t too far away here.

[marcosdumay]

They are quite mundane assumptions. As they said, an electrolizer is a very simple thing. I wouldn't be surprised if they already are testing something that gets close to those numbers.

The real hard part for the H2 generation is scaling it. And the real hard part of their goal is the CO2 capture.

[nkurz]

The title of this article is correct but seems to be misleading some readers. Their goal is not to produce hydrogen, but to produce synthetic natural gas. Using solar to produce hydrogen as a precursor is just the particular approach they've chosen:

We’re developing a scalable electrolyzer to deliver the cheapest possible green hydrogen, which we use as a precursor chemical to make cheap synthetic carbon neutral natural gas in our Terraformer.

As a result, some of the comments so far that correctly point out the difficulties of establishing a hydrogen infrastructure are missing the point. They aren't planning to distribute hydrogen, and don't need such infrastructure. Instead, they're planning process the hydrogen immediately and internally and then piggy-back on the existing natural gas infrastructure.

[namibj]

Note that large amounts of natural gas distribution networks are hydrogen-capable, and adding decarbonization reactors to the supply allows CO2-free operation of formerly natural gas appliances.

IIRC the process is thermal cracking of the methane, which can use solar energy.

[evilsaloon]

"Green" hydrogen is anything but. Electrolysis is a fundamentally inefficient technique. Scale it all you want, but you will hit diminishing returns faster than with water desalination. Natural hydrogen is the way to go, and I hope hydrogen wells will become as ubiquitous as gas wells in 50 years' time.

[acdha]

> Electrolysis is a fundamentally inefficient technique

Yes, but if we’re seeing huge overproduction times on renewables that might not be a showstopper. Hydrogen is a poor choice for powering things like cars compared to the alternatives but if you have industrial processes which need a flame on the order of 2,000°C it could make sense to have peak capacity wind/solar splitting hydrogen & oxygen for those.

[narrator]

According to some reports, there are enormous amounts of "gold hydrogen," that is hydrogen in underground deposits, that's just waiting to be extracted:

https://www.newscientist.com/article/mg26134760-500-the-gold... ( https://archive.is/4g6dw )

How this enormous non-polluting energy source went unnoticed for decades is mystifying to me. That Toyota and other big auto manufacturers are investing in hydrogen fuel cell and even hydrogen combustion engines means that many people who know what they're doing are betting on this future. The math doesn't really work that well for a "green hydrogen" future, but it may work for a "gold hydrogen" future.

[iamgopal]

I was under assumption that, to reach $1/kg, hydrogen should be byproduct of electrolysis of sea water with additional products such as chlorine, calcium carbonate ( precursor of cement ? ), other precious metals, etc combined to reduce price of the hydrogen.

[sudohackthenews]

To extract 1kg of hydrogen with electrolysis you need ~50 kWh with inefficiencies (39.4 with no losses)[0], while one kilo of hydrogen only has 33.6 kWh[1]-roughly 1.17kWh to produce 1 kWh worth of hydrogen (no losses). For diesel, it seems to be quite similar-roughly 1.18 kWh per 1 kWh, however in reality at current efficiencies for hydrogen it is more like 1.5 kWh/1kWh. It seems companies need more incentive to switch to hydrolysis based solutions to cancel out the much higher costs of hydrogen storage

[0] https://www.weforum.org/agenda/2023/09/seawater-electrolysis...

[1] https://rmi.org/run-on-less-with-hydrogen-fuel-cells/

[Saris]

How far does an average car go on 1kg of Hydrogen?

[postpawl]

“One kg of hydrogen contains about the same energy as a gallon of gasoline. Today a fuel-cell electric vehicle with 1 kg of hydrogen can drive approximately 60 miles, compared to conventional vehicles, which get about 25 miles on a gallon of gasoline.”

Source: https://www.energy.gov/eere/vehicles/articles/hydrogens-role...

[davedx]

From 2023