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After many false starts, hydrogen power might now bear fruit

economist.com

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

#291

Post by jitendrac »

jillesvangurp wrote: post #252
jitendrac wrote: post #16

I think article missed a really large sector which uses coal and produces millions of tons of co2 each year, That is cement industry. Heating clinker to produce cement is energy intensive long process, where big investments towards technology for using Hydrogen can be fruitful.

Wood is basically emerging as an alternative in this sector lately. There are some wood based building materials coming on the market that are cheap, sustainable, light, safe, strong, etc. Think people building sky scrapers in areas with exposure to earthquakes and tropical storms safe. I'm talking about Tokyo. https://www.theguardian.com/cities/2018/feb/16/plyscraper-ci... Hydrogen is not really needed to fix this.

yup, new innovation is needed in construction. But wood is not gonna replace all cement-concrete use-cases.Cement-concrete has far more usecases from skyscrapers like bridges,Dams to road construction.

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

#292

Post by labawi »

Jedd wrote: post #223
dmix wrote: post #109

Earlier quoted context omitted.

I've read about a couple of solar projects that projected x/kWh and turned out to be much worse in production. Pakistan's big deployment is one example, it was planned to be 100MW but only produced 18MW. Mostly because they didn't factor in the dust that would cover the panels, keeping them clean was very expensive (I'm curious how this applies to other proposed desert deployments). Nor factoring in the typical malai…

> 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…

> doesn't need more water

>improves magnificently with high temperatures

Thermal solar is a solar heat energy source + classic steam turbine. The efficiency of a thermal->electric converter (turbine) is largely governed by the difference between the hot and cold side.

Increasing both the hot and cold side temperatures equally would not increase efficiency, AFAIK it would actually decrease efficiency, and without lots of water, they can't use evaporative cooling either.

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

#293

Post by noctune »

tuatoru wrote: post #187
jepler wrote: post #154

Earlier quoted context omitted.

Check my math: Say a fueling station needs to serve (only) 100 cars per day, providing 50kWh per car. That's 200kW average generation power needed. Ballpark, a 1 m2 solar panel can generate 200kWh/year, or 23W average. (quora answer, 2018). You need .. really? 9100 m2 of area, which is .91 hectare or 2.25 US acres. A 200kW per day (73000kWh/year) wind turbine might stand 25m tall. (uk wind energy report, 2014) Will t…

This is the point (one of the points) that Vaclav Smil makes about renewables: abysmal energy density of production (in Watts/square meter: more like 'intensity' than 'density' to me). The only thing that beats oil is nuclear fission. With everything else, production takes up land that could be used for something else, or isn't being used for something else because it has problems such as distance or inhospitable cli…

Wind turbines can coexist with agriculture without many issues. Pretty common here in Denmark. The biggest problem with building wind turbines on land here is probably NIMBY-ism.

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

#294

Post by kevin_b_er »

svara wrote: post #24

I've been diving into this literature a bit recently, and it's been mostly encouraging. Affordable clean energy is realistic. Clean energy sources are typically the cheapest sources of energy [0]. The intermittent production issue is solvable: At ~150 $/kWh storage, a combination of storage and renewables is the cheapest energy source 95% of the time [1]. The cost of different energy storage methods is coming down ex…

Seasonal energy storage would be astounding. Combine an overkill of renewable energy with seasonal energy storage via hydrogen and you'd have as much energy as you could want.

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

#295

Post by algo_trader »

dredmorbius wrote: post #203
dehrmann wrote: post #150

Earlier quoted context omitted.

If you have cheap enough energy that you're making hydrogen, can't you also make hydrocarbons? Granted, at the efficiencies we're talking, their only real use would be air travel (and petrochemicals, I suppose).

Yes. That's remarkable more sensible than futzing with naked hydrogen molecules, though the challenges here have been great as well. I covered the topic in a series of posts based on then-new research about six years ago. That's ... not developed much further: Primary article: https://old.reddit.com/r/dredmorbius/comments/22k71x/us_navy... Others: https://old.reddit.com/r/dredmorbius/search?q=fischer-tropsc... The ma…

What is the oil-cost-equivalent of existing synfuel technology?

(for uses such as air travel)

IIRC at $150 oil these synfuels were already competitive?

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

#296

Post by xyzzyz »

godelski wrote: post #139
ncmncm wrote: post #102

Earlier quoted context omitted.

It depend where the (carbon in the) methane comes from. If it comes from the ground, the exhaust contributes to global climate disruption. Venting methane is worse, but that would be wasteful, too.

It also depends where the hydrogen comes from. If you produce it from water, your byproducts are oxygen. If you produce it from methane, your byproducts are carbon dioxide. Issue is that water has 2 hydrogens and methane has 4, so typically it is produced by using methane.

Issue is that water has 2 hydrogens and methane has 4, so typically it is produced by using methane.

It’s not really about that, we don’t lack water or methane. The issue is rather about the energy required to produce given amount of hydrogen. Electrolysis requires 2-3 as much energy as steam methane reforming already if you just look at energy of chemical reactions, and moreover, steam reforming requires just heat, while electrolysis requires electricity, which again is more expensive than heat: we produce most of our electricity from heat, and the conversion efficiency from heat to electricity is around 20-30%, so it makes more sense to use all the heat directly instead of going through electricity production stage.

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

#297

Post by zamadatix »

esperent wrote: post #248
zamadatix wrote: post #164

Earlier quoted context omitted.

According to the Wikipedia article cited it takes 30 people 10-15 days to clean all 392,158 panels fully. That sounds like $100,000/y in raw wages but it seems to be limited by water supply more than raw labor cost. The dust being cited as 40% of the panel efficiency loss and not always being an issue depending on the season also drives some of that RoI down, looks like a good portion of the loss is due to the heat a…

You're off by a factor of 10 based on wages for cleaners in Pakistan which is about $1/hr. http://www.salaryexplorer.com/salary-survey.php?loc=164&loct...

Using the average number from that source you get 356,000 PKR yearly * 30 people = ~$64,000, even using the low end from that site is only a factor of 2 off not 10. The numbers were actually based of the high end from above in the chain "for one laborer to clean panels is probably about $250-300 a month (USD equivalent, in rupees) in that area. That would be a good wage compared to construction work or farm work in that region." which corresponds very well to the high end from your source of 540,000 pkr.

This comes out to ~$97,000 which is how I came up with about $100,000/y.

Just to note this isn't something you do for just one month per year if that's how you came to a factor of ~10.

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

#298

Post by ianai »

indigo945 wrote: post #275
ianai wrote: post #207

Earlier quoted context omitted.

Agree. They could probably just have people walk around with blowers to blow the sand off.

I would suggest that blowing off sand with a strong airstream would scratch the solar panels, further reducing their efficiency. Or maybe there's other problems; in any case, I find it somehow ignorant to assume that nobody in the Pakistani government has ever heard of or considered a blower (or a broom).

I assume they have heard of blowers and probably knew sand would be a problem with this install. My take away is that project was a bad faith effort to serve as a strawman against renewables for oil. This is an engineering problem not a technological problem of solar panels. Having skipped over it implies questionable motivations.

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

#299

Post by manfredo »

pfdietz wrote: post #289
manfredo wrote: post #212

Earlier quoted context omitted.

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 o…

You seem to be under the impression that the cost of hydrogen storage comes almost exclusively from the cost of electricity used for electrolysis of water. This is not the case. Even if we assume zero electricity costs, th cost of storing hydrogen amounts to over a thousand dollars per KWh.

Current estimates place this at $1,400 per KWh per year for the average case assuming that the electricity provided is free [1]. That works out to $3.80 per day per kilowatt hour of storage. Even for the optimistic estimated provided by this study, it's still $800/KWh/year - still over $2.00 per day. And again, this is assuming that free excess wind generation is used to get generate hydrogen.

Us retail energy costs are about $.13/KWh. Industrial costs are $.07/KWh. For diurnal storage, hydrogen energy storage represents a 20x cost increase even in the best case estimates for the storage cost and assuming that excess wind generation will pick up th slack.

And for non-diurnal storage the costs are even higher per KWh because a smaller amount of delivered electricity needs to pay off the same amount of capacity cost.

Also, before you point at figure 16, know that this graph includes "capacity credits" - it's not the actual cost.

1. https://www.google.com/url?sa=t&source=web&rct=j&url=https:/...

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

#300

Post by hansvm »

jimmcslim wrote: post #236
mrpopo wrote: post #72

Earlier quoted context omitted.

Do you know more about hydrogen transport? I heard it is quite more complicated and expensive than LNG (closest equivalent), because hydrogen leaks more easily.

There's also the issue of hydrogen embrittlement of steel, which is probably what causes the leaks I guess?

Hydrogen is also really small and can seep out of seals that we would ordinarily consider air-tight.
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