HackerTrans
TopNewTrendsCommentsPastAskShowJobs

Manfredo_1

no profile record

comments

Manfredo_1
·5 năm trước·discuss
> And you still are pretending that steam power plants running on hydrogen don't exist.

Yet again, you originally said we could use gas turbines for hydrogen storage. Not steam turbines. Of course steam turbines can easily be run off hydrogen, you don't need compressor blades, combustors, or anything special. Just a source of heat, a boiler, and a steam turbine. This is less efficient, so there's good reason to develop hydrogen gas turbines.

You're the one who first brought up steam turbines when you changed the goal posts to saying we could repurpose coal plants instead of gas turbines.

And good night.
Manfredo_1
·5 năm trước·discuss
I didn't reject future hydrogen gas turbines. In fact, I'm the one who brought them up. That's the entire point I'm making: hydrogen gas turbines are still in development. If hydrogen gas turbines already exist, why are GE, Siemens, and others talking about how they plan to develop hydrogen gas turbines by 2030 or 2040? They're not off the shelf technology, because they aren't even on the shelf yet.

Im going to bed now, and I should have realized I was being trolled much sooner.
Manfredo_1
·5 năm trước·discuss
An electric car is as green as the grid that powers it. But a hybrid will never be green even if the grid is 100% green because it still burns fossil fuels. Same with a turbine that consumes a mixture containing natural gas. If your generator uses fossil fuels it's emitting carbon dioxide.
Manfredo_1
·5 năm trước·discuss
Why? Electric cars don't use a mixture of gas and batteries. Those cars do exist and we call them "hybrids". But those are not carbon neutral and we don't pretend they are.
Manfredo_1
·5 năm trước·discuss
The goalpost never moved. If you want to use hydrogen storage in a carbon neutral grid you need 100% hydrogen fuel. We're not there there yet. And we won't be there for the better part of a decade, or longer.

I guess I'll keep "fucking that chicken" along with GE and Siemens and the companies that actually build gas turbines.

> So your own source disagrees with you.

Did you miss the "in 2030" part?
Manfredo_1
·5 năm trước·discuss
Most companies are targeting hydrogen gas turbines to be produced in 2030 or 2040: https://www.siemens-energy.com/global/en/news/magazine/2019/...

They aren't "off the shelf" technology yet.
Manfredo_1
·5 năm trước·discuss
Why would it count in the context of climate change? It's still emitting carbon dioxide into the atmosphere. And again, this is one specific model. Many gas turbines are only capable of much smaller concentrations: https://www.siemens-energy.com/global/en/news/magazine/2019/...

You're going from "we can just run existing gas turbines with hydrogen" to "this one specific gas turbine can use mostly hydrogen fuel but still needs 30% natural gas". Again 90% was peak not average hydrogen concentration.

Companies are looking at developing natural gas turbines that run on 100% hydrogen. But they're targeting 2030 or 2040. Are you going to tell GE and Seimens to shove their head up their ass, too?
Manfredo_1
·5 năm trước·discuss
> So how else we're suppose to interpret this statement: "No, hydrogen rapidly corrodes any metals that it comes into contact with. If they are interchangeable, expect drastically smaller service intervals."

I'm not sure why you're having trouble comprehending it. Existing gas turbines are meant to run on either oil or natural gas, not hydrogen. In addition to corrosion, hydrogen burns hotter.

You cited one specific turbine model that had a peak hydrogen mixture of 90% (average was 70%). Ignoring the fact that you're picking one specific model that's being highlighted for it's ability to accept hydrogen fuel, this still isn't viable for a carbon-neutral storage system since it still burns natural gas. No, we can't just run them at 90% for years on end because that will still advance climate change.

> Either new or existing, this isn't a hard challenge, especially considering we replace old turbines all the time.

It's good that you're admitting that it's not a simple matter of modifying existing turbines, and that new turbines have to be developed. But it is an additional bottleneck, it's not just a matter of electrolysis we also have to build the generation infrastructure to turn that hydrogen back into electricity.

Likewise if you interpreted my original comment as saying that it's impossible to run a gas turbine with hydrogen that is indeed incorrect. Though I'm rather unsure of how you reached this interpretation given that I even provided an example of a soviet experiment with hydrogen jet engines (albeit with significantly shorter flight time).
Manfredo_1
·5 năm trước·discuss
> nevermind this whole goalpost moving argument of "current gas turbine already in existence."

This was the original goalpost. Let's re-read it: https://news.ycombinator.com/item?id=26599162

> Those gas turbines you're referring to can simply be modified natural gas gas turbines. The only limiting factor would be electrolysis, but that is already something people are planning to build a lot of.

This is wrong, we'd have to build new gas turbines to run on a 100% hydrogen mixture in addition to building electrolysis capacity. At this point I think it's clear you're not interested in engaging honestly, and in the other thread you'e already started to throw around ad-hominem insults [1].

1. https://news.ycombinator.com/item?id=26599959
Manfredo_1
·5 năm trước·discuss
> This whole started because no one here thought someone would seriously try to argue that hydrogen gas turbines are impossible. For some of us this was too obvious to even bother trying to debunk.

Now you're just straight up lying. Nowhere did I claim that hydrogen gas turbine was impossible. In fact I even provided an example of the soviets experimenting with hydrogen powered jets. Do you realize that a jet engine is a gas turbine?

What I did say is that you can't just repurpose the existing fleet of natural gas turbines for hydrogen generation. I'm well aware that companies are working on 100% hydrogen turbines, but even the examples you cited require a mix of natural gas.
Manfredo_1
·5 năm trước·discuss
If we aren't using combined cycle gas turbines round-trip efficiency of hydrogen storage is seriously reduced.

I'm not moving any goalpost. This is your comment when you claimed that gas turbines could be repurposed to burn hydrogen: https://news.ycombinator.com/item?id=26599162

> Those gas turbines you're referring to can simply be modified natural gas gas turbines.

> It's past time to admit you were wrong.

Follow your own advice. You can't just feed a gas turbine hydrogen and run it as normal. Existing gas turbine manufacturers don't plant to offer 100% hydrogen gas turbines for decades.
Manfredo_1
·5 năm trước·discuss
Yes, I'm familiar with moving the goalposts. It's exactly what you've been doing in this thread. First you claimed that existing natural gas turbines could be modified to run hydrogen. That hydrogen turbines usable for grid generation were off the shelf. After realizing that these turbines only burn a mixture of 30% hydrogen and 70% natural gas you moved to goalpost to saying, "we have experience with hydrogen turbines". I certainly don't doubt the latter - in fact I'm the who provided evidence of it! But that doesn't have much bearing on your first goalpost: that the existing fleet of gas turbines can be powered with hydrogen.

For the third time, if this modification is so simple why is GE saying it won't be until 2045 that its turbines will be able to run 100% natural gas? Hydrogen gas turbines are not off the shelf devices.
Manfredo_1
·5 năm trước·discuss
Sure, we could burn hydrogen and drive a boiler like a coal plant. But that's not where this comment thread started.

> Those gas turbines you're referring to can simply be modified natural gas gas turbines

Sure, if you just want to run them for a short period of time and generate a lot more wear. If these turbines are so simple to modify, why does GE say that it won't be until 2045 that their turbines will be able to run 100% hydrogen gas?
Manfredo_1
·5 năm trước·discuss
Right. Lithium batteries won't cut it. That leaves geographically-dependent hydroelectricity, which isn't so easy to build. And then proposed solutions that are still in the prototyping phase, and aren't commercially available.
Manfredo_1
·5 năm trước·discuss
It was done for a very short duration during the 1980s as a technology demonstrator. A prototype, not an actually commercially viable product. Yes, we can improve on a 33 year old technology, but it's not something we can just buy off the shelf. GE thinks it'll take until 2045 to make turbines that run off of 100% hydrogen.

> How dishonest are you going to get before you will admit you were wrong?

When you show me where I can buy a gas turbine that runs off of hydrogen. Not a gas turbine that runs mostly off of natural gas with a little bit of hydrogen mixed in. Not a press release of a company saying "we have experience with hydrogen turbines". If you're going to say that hydrogen gas turbines are off-the-shelf then show me the shelf off of which I can buy it.
Manfredo_1
·5 năm trước·discuss
For the third time, storage is only one part of the puzzle. We also need a way to cheaply electrolyze water into hydrogen, compress it into the storage facility, and then use it to generate electricity. Nobody doubts that you can pump hydrogen into a big cave. What's dubious is transforming this into a usable energy-storage facility.

We haven't done this to provide 100 MWh of storage. How on earth can we be confident it'll be easy to provide 1 TWh of storage, or 10 TWh?

People mostly talk about lithium ion storage because that's what's actually available, besides geographically limited options like hydroelectricity. Until there's a company that's building dozens of gigawatt hours of hydrogen storage it's a moot point. It's a technology that exists the laboratory, not one that's commercially available.
Manfredo_1
·5 năm trước·discuss
Right, but then we're not talking about combined-cycle gas turbines to convert hydrogen back into electricity. If we're going to boil water than that's much less efficient than the ~66% efficiency we get out of combined cycle gas turbines.

Also, in case you weren't aware a combined cycle turbine also involves boiling water and spinning a turbine. The reason why they're so efficient is because energy is extracted both from the gas turbine (basically a jet engine) and a steam turbine driven by the heat from the exhaust from the gas turbine.

>Honestly, you should learn some thermodynamics and chemistry before accusing others of being ignorant.

Hydrogen embrittlement is a real thing, don't just go hand-waving it away: https://www.energy.gov/sites/prod/files/2014/03/f12/hpwgw_em...

What about thermodynamics am I missing?
Manfredo_1
·5 năm trước·discuss
> A gas turbine burning hydrogen does not experience any stresses that is meaningfully different from one burning natural gas or kerosene. Simply applied engineering can solve all of the issues associated with hydrogen gas turbines.

Did you misread that comment? The point was that hydrogen's application in the chemical industry don't involve turbine blades spinning at extreme speeds at high temperatures.

Yes, the principle of combusting a gas, driving a turbine with the expanding gas, and using that turbine to drive a compressor is the same. That doesn't mean you can just feed a gasoline powered turbine hydrogen and be done with it. The turbines that can run hydrogen today can only run a small portion of it.

https://www.economist.com/science-and-technology/2020/12/08/...

> The challenges of using hydrogen go beyond body shape, though. Redesigning a turbine engine to run on the stuff will be a multi-billion-dollar endeavour. Hydrogen burns faster than kerosene, and also burns hotter. That means materials exposed to its combustion experience greater stresses. It also risks increasing the pollution generated in the form of oxides of nitrogen, which would partially negate the environmental benefits of burning hydrogen. And it would be useful as well to arrange matters so that some of the energy used to compress or liquefy the hydrogen for storage could be recovered and put to work.

The Soviets built a plane that flew on hydrogen, but it only completed 100 flights. And only part of those were with hydrogen, the rest were with natural gas: https://en.wikipedia.org/wiki/Tupolev_Tu-155
Manfredo_1
·5 năm trước·discuss
A solar heavy network would still need 12 hours of storage to accommodate nighttime energy use. More actually, because of greater seasonal fluctuations further from the equator.

All of the Americas experience night time simultaneously for at least 8 hours a day. Even if we ran HVDC lines to the Sahara, there's still a period of time where most sunlight is shining on the pacific ocean.
Manfredo_1
·5 năm trước·discuss
That link you provided doesn't encompass gas turbines. Gas turbines capable of burning hydrogen do exist, but only at smaller concentrations, 70% methane and 30% hydrogen or less.