Toyota and Yamaha join forces to develop hydrogen-fueled V8 engine | Hacker News Reader

Toyota and Yamaha join forces to develop hydrogen-fueled V8 engine

interestingengineering.com

18 pointsmardiyah15 comments

Generally an ICE engine has poor efficiency. Gasoline engines have about 25% efficiency. To increase the efficiency, you need to burn hotter (the ideal Carnot engine has an efficiency of 1- T-hot/T-cold; there’s not much you can do about T-cold -> it’s just the ambient temperature, so you need to increase T-hot). Diesel engines do just that; despite the fact they are further away from the ideal engine than their Otto cousins, they burn so much hotter that they have a much better efficiency (up to 45%). But now they have another problem: they burn so hot that they burn part of the nitrogen in the air. That produces nitrogen oxides. Popularly known ad Diselgate, or the Volkswagen emissions scandal.

So with am ICE, you either have poor efficiency, or you produce NO_x pollution. Which one is it?

This is why modern diesels use DEF. It's just hot Urea solution that is sprayed through the diesel exhaust stream which reacts with the NOX after the first pass through the diesel oxidation catalyst. Urea and the nitrous oxide become nitrogen, water, and CO2. Hydrogen engines may need to use a DEF process like diesels eventually. Especially since hydrogen combustion is really good at making NOX.

https://www.autoserviceprofessional.com/articles/7257-diesel...

https://www.capitalremanexchange.com/20-facts-you-need-to-kn...

What’s the energy efficiency of this ? My basic knowledge would let me think it’s not even worth developing a proof of concept but maybe they are just doing some green washing.

Hydrogen is far superior to batteries if we get the storage tech right. You can transfer it as quickly as gasoline, meaning you can fill up in 3 minutes and drive hundreds of miles and fill again indefinitely. It could be thousands of pounds lighter than batteries. It never goes bad or wears out, and has the same performance in extreme cold and hot temperatures.

Yes. I drove a hydrogen car a few times some years ago. The hydrogen infrastructure wasn’t very developed and is gone today. The electric grid is developed and I have fast chargers everywhere. For sure I need to plug the car a bit longer but it’s not really an issue. I’m not driving hours and taking only a 3 minutes break.

I think hydrogen is an okay solution when high density energy storage is required. But for passengers cars it’s just not great.

Most of this is pretty much nonsense. Battery system are already lighter, and with next generation structural batteries cells like next generation Tesla and BYD the battery added weight of batteries compared to pure structure isn't actually that large.

Next generation vehilces will actually be lighter then comparable ICE vehicles, specially when fully fueled.

An Hydrogen ICE engine is pretty much the worst of all world. You don't get the amazing driving experience of an EV powered vehicle and you have to pay far more for your fuel.

And bringing back emissions and driving with ICE is really just next level stupid.

There is a reason pretty much every non-Japanese company has declared the technology dead. And those that work on it mostly still do it based on government funded project supported by fossil fuel lobby.

If electricity is cheap enough, what does it matter if its only 10% efficient? just means it is expensive to store energy.

Maybe its greenwashing, but it is also a hedge against battery tech. I know most people here have already made up their minds that BEV is the only way forward, but does it hurt to have competition?

As long as they don’t ask for a handout to catch up when hydrogen flops, sure. This is the problem we face with limited resources: we can’t give equally to all, so we have to prioritize by probable outcome based on currently available information (see renewables, fission, fusion as well).

But that's what's happening with electric too? Heavily subsidized in most countries they're sold

Somewhat true, but EVs are delivering today. There are ~2 million EVs being manufactured annually at current run rates (Tesla + legacy auto), and EV charging networks are already robust throughout the developed world (home charging, fast dc charging), while also rapidly growing by the day. Hydrogen has shown immaterial progress in the last two decades, and there are only a handful of hydrogen fueling stations.

They are not equal. Combustion for light vehicles is arguably dead. Toyota was too risk adverse and is paying the price.

They need way fewer subsidies to be competitive with fossil fuel burners though since they are a lot cheaper. Furthermore no (almost no and no financially sustainable) green H2 exist so cars run with grey H2 which ruins car companies fleet emission profile (barely better than diesel) so they can't be sold in big numbers in Europe.

H2 burning motors like this one have even worse electricity to mile ratios then hydrogen fuel cells.

If you are going to use hydrogen, use a hydrogen fuel cell. Not a V8 internal combustion engine.

I was hoping the article would include a comparison to that option, but sadly, no. Is it safe to assume that a fuel cell + electric motor has much higher efficiency than this hydrogen ICE, at comparable weight?

Why bother with an actual engine if we are using hydrogen for whatever reason? It reintroduces NOx emissions for less efficency. Fuel cell conversion is more efficient than heat engines are. And production is already a big haircut. Hydrogen is already a crazy corrosive lighter than air escape artist. If it wasn't such a problem child, then niche high capacity storage for surplus electric generation could justify worse round trip efficency.

I would prefer to see this kind of advancements in motorcycles, where adding batteries or hydrogen fuel cells are not only costly but also a huge weight burden.

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