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Comment by phicoh | Hacker News Reader

Maybe there is the thing that hardly any hydrogen is created from non-fossil sources.

Given the challenge of bringing enough green electricity online, producing enough green hydrogen for industry, it is extremely unclear how we can afford to waste a lot of green electricity in producing green hydrogen for cars.

Of course, by the time customers find out about the price difference they will dump their FCEV cars.

So at the moment, hydrogen is produced from methane. And indirectly produces as much CO2 as ICE cars.

Due to their enormous efficiency, BEV cars can indirectly produce less CO2 even is electricy is generated from fossile fuels. And with enough nuclear, wind or solar, CO2 can be a lot less.

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But in many regions, you can say the same about electricity. Renewable energy is ~29% of world electricity generation [0]. Just like there's ongoing work to increase the share of electricity generated from renewable sources, there's also ongoing work to increase the share of hydrogen generated from renewable sources.

Regarding energy production and costs, if FCEVs can be made to work near-term, they'd actually be a valuable tool to aid in the transition. From [1], if you're using natural gas to power a car (which we will, for years to come), you can use 1.18 to 1.77 MBTU to carry a conventional BEV 300mi, or you can use 0.81 MBTU to carry an FCEV 300mi. That means the fuel can be cheaper and the emissions substantially lower than a BEV during the transition period. By the time the transition period is over, FCEVs may be more mature.

And I think the idea that people will dump FCEV cars assumes too narrow an idea of what an "FCEV" will be. Imagine, for example, a BEV with a hydrogen tank in the back. You can use the batteries for short trips like commuting and hydrogen for extra range when you really need it. This way, people could buy a car with batteries for say 100mi (driving down the cost and weight of the car substantially) knowing that if they need to drive further, the hydrogen tank can carry them a few hundred miles more.

[0]: https://www.iea.org/reports/global-energy-review-2021/renewa...

[1]: https://www.energy.gov/sites/default/files/2014/03/f9/thomas...

Any FCEV is basically a hybrid EV. The obvious reason is that the fuel cell doesn't generate enough power. So you need a battery as buffer.

When it comes to fossil fuel, any ICE is cheaper than FCEV based on grey hydrogen. It is very unlikely that governments will ban regular petrol or diesel any time soon and at the same time allow grey hydrogen. As long as you can buy ICE vehicles, it is extremely unlikely that anyone will invest in a fine grained hydrogen distribution network. Governments are not going to massively subsidize (distribution of) grey hydrogen.

When it comes to green hydrogen, green electricity is cheaper. Fast chargers compete well with filling up with hydrogen. And don't require the extremely delicate distribution structure of hydrogen.

In short, FCEV was a thing before Tesla. Before Tesla is was not clear how we would do long range driving, who take initiative to install chargers, etc. Now all of that is sorted out. We also know how to scale the production of batteries.

FCEV can go on display next to steam engines.

FCEVs will end up being far cheaper than BEVs. Hydrogen production doesn't not have the same uptime requirements that directly electrification requires. It's quite likely that green hydrogen will be cheaper than grid electricity pretty soon. I think people will find out that make green hydrogen is easy, but green electricity is not.

That is unlikely because cheap hydrogen can be used to stabilize the grid.

So with green hydrogen, the grid consists of cheap green energy or electricity from hydrogen. In areas with lots of solar, you can charge your car during the day and forget about more expensive electricity during the night.

In contrast, a FCEV always pays a higher price because hydrogen needs to be produced from green electricity and the fuel cell also has significant losses. So with hydrogen you can never be lucky.

If you're making grid electricity with hydrogen, it will be as expensive or more so than something that directly uses the hydrogen. You also are going to be forced to charge during the day, the exact opposite of how people use their EVs. Finally, hydrogen will make up the majority of power production for those long stretches of low wind and cloudiness. In all likelihood, grids will be built around the existence of hydrogen storage, not the other way around.

People will quickly figure out what is cheaper. And that is using electricity as it is generated. Second best, if it is predictable, store electricity in batteries. Most likely a home that has enough solar panels, can store energy temporarily in a house battery and then transfer it to a car cheaper than having the car run on hydrogen.

Any FCEV has a battery that in theory can be charged from the grid. So FCEV owners are also interested in charging their cars at work.

Making grid electricity with hydrogen is expensive, but is only need for a fraction of the time. So on average you come out ahead.

There may in the future be an interesting difference in regions. Some regions can combine hydro, wind, solar, etc. and have cheap electricity. Other regions are not so lucky.

Which is going to be hydrogen, not charging from the grid, for long stretches of time if not all the time. The cost of solar panels plus batteries will add significant cost and make it less cost effective than large-scale production of hydrogen. Not to mention that only a minority of people will have access to this.

Plug-in FCEVs exist. They can react flexibly to energy costs if hydrogen suddenly gets more expensive. They make more sense than a car that only runs on electricity.

If by "fraction of the time" you mean upwards of 100% of all grid energy for weeks on end, then yes it is a fraction of the time. In reality this is such a large factor that it will drive hydrogen costs to below grid electricity for very long periods and over large areas. Some communities might even think of getting off the grid and generate all electricity from hydrogen directly. In such cases hydrogen will always be cheaper.

While it will make sense for some communities to stick with direct electrification, this is going to be the rare case where dependable renewable electricity exist. It will also likely force BEVs into driving "islands", as it would not make sense to drive a BEV outside those specific regions. Ultimately, BEVs will end up mostly as commuter cars intended for short range trips. This will also drastically reduce the problem of battery e-waste and eliminates the need for vast numbers of fast charging stations.

I think you underestimate how much green hydrogen is going to cost. Yes, it would be great if green hydrogen is going to be as cheap as petrol today. No need to worry. However, that is just very unlikely. Just basic physics how much energy you need to put in.

Solar panels are cheap. Batteries are cheap if you can use them every day. Indeed not everybody has a drive way.

Weeks on end sounds very dramatic. But the important number is what fraction of the year. Combining solar and means that a very large fraction of the year there will be green electricity.

If you need to produce large amounts of green hydrogen, then you need to massively overbuild green electricity production. And this increases the fraction of time that there is green electricity.

With respect to islands of BEV. That is a bigger risk for FCEV. It is very unlikely that a BEV island would have a hydrogen infrastructure. On the other hand, in an area dominated by hydrogen, it is still cheap to provide a few fastchargers. Maybe the elctricity won't be cheap but the charger setup is not that expensive, so you can expect them on major highways. Which will make FCEV the car for commutes.

In any case, I'm curious which country will actual role out a fine grained network for green hydrogen. I very much like to know what green hydrogen will cost 'at the pump' if there are no subsidies.

Green hydrogen will be cheaper than petrol. The goal is to make it from curtailed renewable energy which will cost <$0.02/kWh. You can't go around talking about cheap solar and not realize it means cheap hydrogen too.

It will be a significant fraction of the year that will be powered by hydrogen as the primary energy source. Just creating more green electricity will mostly end up wasting it as there is no other way of capturing and storing it.

All regions must have hydrogen available. For things like industry, shipping, trucking, grid energy storage, etc., it is basically unavoidable for a country to not hydrogen. BEV islands will be small and not an alternative to widespread deployment of hydrogen-related infrastructure. But the reverse is not true, as it is fully possible for a country to reach zero emissions with no BEVs.

The biggest change in environmental policy is the widespread deployment of hydrogen and related technologies. Many countries now like the UK, Germany, Australia, Japan, etc., have very significant hydrogen expansion policies. These policies will accelerate rapidly going forward.

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