After many false starts, hydrogen power might now bear fruit • Hacker News Board

Re: After many false starts, hydrogen power might now bear fruit

#281

Post by roelschroeven » Sun, Jul 05, 2020, 12:20 PM UTC

sir_bearington wrote: post #232

roelschroeven wrote: post #193

Earlier quoted context omitted.

> The cost of storing waste is miniscule. Then how come that not a single country has yet developed a method for storing their nuclear waste safely and permanently? From your first link: > The fuel is either enclosed in steel-lined concrete pools of water or in steel and concrete containers, known as dry storage casks. > For the foreseeable future, the fuel can safely stay at these facilities until a permanent dispos…

> > With the zeroing of the budget for Yucca Mountain nuclear waste repository in Nevada, more nuclear waste is being loaded into sealed metal casks filled with inert gas. Many of these casks will be stored in coastal or lakeside regions where a salt air environment exists, and the Massachusetts Institute of Technology is studying how such dry casks perform in salt environments. Some hope that the casks can be used f…

I wasn't very clear. One of the links mentioned that not only Yucca Mountain is a good solution, but also that the temporary storage that's used in the meantime is perfectly safe. That's what I objected to with that quote.

Re: After many false starts, hydrogen power might now bear fruit

#282

Post by Jedd » Sun, Jul 05, 2020, 12:34 PM UTC

sho wrote: post #267

Jedd wrote: post #223

Earlier quoted context omitted.

> Pakistan's big deployment is one example .. A valid example of what can go wrong when you pick the wrong technology, don't do small scale trials first, and rely on government oversight. (Refer the Background & Operation section of the wikipedia article -- toe-curlingly alarming, yet ultimately unsurprising.) They almost definitely should have pursued concentrated solar thermal. It partly solves the 'storage problem…

> what can go wrong when you [..] rely on government oversight > this sounds like a traditional government project problem I don't know why you're trying to turn this into an "obviously govt can't do anything" point. There are plenty of very well-run governments who would have ably foreseen and solved these problems. And no doubt there's any number of private companies who would have screwed up just as badly. Trying…

> > what can go wrong when you

You're mis-quoting me. Is this intentional?

I understand paraphrasing, but there's better (and more accurate) ways of doing that.

> I don't know why you're trying to turn this into an "obviously govt can't do anything" point. There are plenty of very well-run governments who would have ..

FWIW it wasn't a 'no government can do anything' claim.

I have no doubt that there are a number of government agencies that can do things.

The fact that this particular project delivered a measurable 20% of projected outcomes is the point.

If you have some alternative interpretations of this outcome, they'd be very welcome.

> And no doubt there's any number of private companies who would have screwed up just as badly.

Are you suggesting I can't claim something is bad -- because something else would be just as bad?

> Trying to tar the entire idea of government with Pakistan's performance is pretty bad faith IMO.

This is a bold leap, and no faith is involved.

Re: After many false starts, hydrogen power might now bear fruit

#283

Post by Jedd » Sun, Jul 05, 2020, 12:47 PM UTC

igravious wrote: post #273

sho wrote: post #267

Earlier quoted context omitted.

> what can go wrong when you [..] rely on government oversight > this sounds like a traditional government project problem I don't know why you're trying to turn this into an "obviously govt can't do anything" point. There are plenty of very well-run governments who would have ably foreseen and solved these problems. And no doubt there's any number of private companies who would have screwed up just as badly. Trying…

Amen. Not just bad faith; ignorant, myopic and ahistorical. > this sounds like a traditional government project problem -- susceptibility to corruption, vanity, hubris etc. said the person on a web forum (the web comes from CERN, a gov project) over the internet (the internet comes from DARPA, a gov project) on a computer (ever heard of the ENIAC? a gov project) Tech bros mouthing off off-topicly about the government…

> Amen. Not just bad faith; ignorant, myopic and ahistorical.

Referring to GP's wikipedia reference, can you explain the two 'for unknown reasons' on a) why the original (Canadian) contract was not engaged, and b) the Turkish project was not engaged.

What precisely was ashistorical about any of my post?

> > this sounds like a traditional government project problem -- susceptibility to corruption, vanity, hubris etc.

> said the person on a web forum (the web comes from CERN, a gov project) over the internet (the internet comes from DARPA, a gov project) on a computer (ever heard of the ENIAC? a gov project)

I really am bewildered.

Are you claiming that because I'm using the Internet I am not authorised to claim that any government project in any country at any time is beyond questioning?

> Tech bros mouthing off off-topicly about the government is the most tedious and boring thing ever.

Goodness.

I'm sorry you're bored, I'm not a tech bro, claims of poorly run projects within the land of the pure isn't off-topic to the claims made.

Re: After many false starts, hydrogen power might now bear fruit

#284

Post by Jedd » Sun, Jul 05, 2020, 1:02 PM UTC

heavyset_go wrote: post #238

Jedd wrote: post #219

Earlier quoted context omitted.

During the night and very early morning, probably very little.

Evaporation often happens at night because of the temperature differences.

> Evaporation often happens at night because of the temperature differences.

I'm not sure the phrase 'temperature differences' exhibits a profound understanding of evaporation.

If a location gets 45c (as per GP's reference) during the day, this doesn't necessarily speak to night time temperatures.

I'll note that Bahawalpur's temperature profile is available at:

https://weather-and-climate.com/average-monthly-Rainfall-Tem...

For the three hottest months of the year the average lower temperature is around 25C, which suggests quite a low evaporation rate overnight.

It would be great if you could provide some more detailed insights.

Re: After many false starts, hydrogen power might now bear fruit

#285

Post by [deleted] » Sun, Jul 05, 2020, 2:01 PM UTC

philipkglass wrote: post #134

elago wrote: post #113

Earlier quoted context omitted.

According to the U.S. Department of Agriculture, the U.S. has 434,164,946 acres of “cropland”—land that is able to be worked in an industrial fashion (monoculture). This is the prime, level, and generally deep agricultural soil. In addition to cropland, the U.S. has 939,279,056 acres of “farmland.” This land is also good for agriculture, but it’s not as level and the soil not as deep. Additionally, there is a vast am…

US oil consumption for transportation was 14.16 million barrels per day (595 million gallons per day) in 2018: https://www.eia.gov/energyexplained/oil-and-petroleum-produc... That's 595,000,000 * 365 = 217,175,000,000 gallons per year of oil. Using 100% of cropland producing at 369 gallons of ethanol/acre gives 434,164,946 * 369 = 160,206,865,074 gallons per year of ethanol. That's only 74% as many gallons as oil con…

[deleted]

Re: After many false starts, hydrogen power might now bear fruit

#286

Post by dredmorbius » Sun, Jul 05, 2020, 2:02 PM UTC

dredmorbius wrote: post #199

elago wrote: post #113

Earlier quoted context omitted.

According to the U.S. Department of Agriculture, the U.S. has 434,164,946 acres of “cropland”—land that is able to be worked in an industrial fashion (monoculture). This is the prime, level, and generally deep agricultural soil. In addition to cropland, the U.S. has 939,279,056 acres of “farmland.” This land is also good for agriculture, but it’s not as level and the soil not as deep. Additionally, there is a vast am…

I (and many others more qualified) have run the numbers. It's not pretty. A decade ago biofuels were my first thought. The maths simply don't add up. Our options are far less energy per person, far fewer people, other sources of energy, or, most likely, some combination of these. The highest claimed yields are for algae, at a rather improbable 1,000 gal/(acre * year): [Y]ou might consider floating the algae offshore,…

Correction: that's David MacKay.

Re: After many false starts, hydrogen power might now bear fruit

#287

Post by BurningFrog » Sun, Jul 05, 2020, 2:17 PM UTC

esperent wrote: post #251

BurningFrog wrote: post #228

Earlier quoted context omitted.

Windshield wipers are a mature and cheap technology that seems applicable.

They are designed to clean water off glass. I've never lived in a dessert area so I may be wrong, but I expect they're not great for cleaning large amounts of dry dust and dirt off at least without using huge amounts of water.

I'd adapt it, of course. Not literal store bought wipers.

Some kind of brush is probably what you need for dust.

Re: After many false starts, hydrogen power might now bear fruit

#288

Post by dredmorbius » Sun, Jul 05, 2020, 2:19 PM UTC

MayeulC wrote: post #204

dredmorbius wrote: post #97

Earlier quoted context omitted.

with batteries, you need to move all the weight for all the journey For metal-air batteries, one of the more promising areas of research, the problem is actually worse: the cells gain mass as oxygen is reacted with the metal anode, discharging the battery. https://en.wikipedia.org/wiki/Metal–air_electrochemical_cell For marine propulsion, heavy fuels are typically preferred (bunker fuel typically, thogh deisel and pe…

> For metal-air batteries, one of the more promising areas of research, the problem is actually worse: the cells gain mass as oxygen is reacted with the metal anode, discharging the battery. That's interesting, thank you for the info. Having a different characteristic from the usual one might lead to interesting applications. For instance, airplanes use a lot of fuel for takeoff, as they pay double the price for the…

More likely, rethinking flight-segment dynamics and design.

The bulk of energy expenditure is on takeoff and climb segments of flight. Cruise is relatively low energy, and during approach and landing, aircraft are frequently effectively gliding. Pilots and aviation engineers speak of the amount of energy in the aircraft, exclusive of fuel, represented by its mass, altitude, and velocity.

Ideas I've seen suggested include catapult or towed launch, ejectable or jettisonable batteries, and/or hybrid fuel/electric designs, exploiting these factors.

The general problems are:

- These all increase complexity and failure risks.

- They are novel (and hence risky) concepts.

- Virtually all have scaling issues, being possibly feasible for smaller (drone, single-passenger, or few-passenger craft), but not heavy or superheavy jumbo jets. (Square-cube relations mean, generally, small aircraft are easier than large ones).

- The typical power requirements are violated in emergencies. Fuel-driven aircraft can apply TOGO (take-off/go-around) power on demand, whilst a hybrid or compound design likely could not. And final flight-phase aircraft typically have half their takeoff weight, having burnt the difference in fuel, further expanding performance options.

As for "lowering the battery", you'd do better to fly the entire aircraft at a gradually descending flight path, trading lower-drag high altitude for higher-drag lift as the battery gains mass. Current long-haul aircraft (sometimes) practice this in reverse, reching higher flight levels as fuel is consumed, lift requirements reduced, and lower-drag high-elevation flight being possible.

Re: After many false starts, hydrogen power might now bear fruit

#289

Post by pfdietz » Sun, Jul 05, 2020, 2:21 PM UTC

manfredo wrote: post #212

pfdietz wrote: post #202

Earlier quoted context omitted.

Underground hydrogen storage is a demonstrated technology, not experimental. All that's required is scaling it up, and there's plenty of room to do that. The only real missing piece was sufficiently cheap electrolysers for use with intermittently available power, but that's coming along very fast now too, with rumors of costs as low as $200/kW in China (and a recent contract win of $350/kW from a European maker of al…

Underground hydrogen storage had the same issue as kinetic storage: it's geographically limited. It's not just a matter of scaling it up, it's also matter to implementing it in places without empty salt mines handy. And as you point out, generating this hydrogen is nowhere near cost efficient. To put this in perspective, energy costs in the US average about $.10-$.20 per KWh [1]. You're literally talking about a 1,00…

> Elaborate on what you mean by emphasizing retail energy costs. That is the cost that customers pay for the electricity that is delivered to them.

It's what a residential customer would pay. It's not what an industrial customer would pay, and it's certainly not the internal cost the utility to pay for their own production of hydrogen. In particular, it includes the cost of supporting the distribution network. None of the power being sent to the electrolysers will be sent over the thousands of miles of residential distribution lines.

It also doesn't take into account that the wholesale price of electricity in power markets varies with time. The residential fixed price is derived from some average of that (plus charges for all the overhead), but the electrolysers could be operated when the wholesale price is low.

> hundreds of dollars per kilowatt hour of hydrogen storage is still a factor of a thousand more expensive.

The capital cost of storing hydrogen in underground cavities is estimated to be $1 per kWh of capacity, and perhaps much less.

Re: After many false starts, hydrogen power might now bear fruit

#290

Post by pfdietz » Sun, Jul 05, 2020, 2:25 PM UTC

carapace wrote: post #241

pfdietz wrote: post #186

Earlier quoted context omitted.

You get much more fuel out of biomass if you add hydrogen. For example, from carbohydrates, it's basically (CH2O)n + nH2 --> (CH2)n + nH2O (hydrodeoxygenation). This can make drop-in replacements for gasoline, diesel, and jet fuel.

That's very interesting. If you've got a ready source of hydrogen, say from molten salt oxidation of plastics, which produces "syngas" (a mixture of CO and H2), I think you could run that through water to make CO2 and more H2, feed the CO2 to a greenhouse and collect all the H2 for the reaction you described. Does that make sense?

You could, but I think it would be better to break the plastics into smaller not-fully-oxidized fragments, and rearrange those into desired chemicals. If the plastics have oxygen (as, for example, PET does) one could use hydrogen to pull that out, if needed.