[HN Gopher] After many false starts, hydrogen power might now be...
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After many false starts, hydrogen power might now bear fruit
Author : helsinkiandrew
Score : 138 points
Date : 2020-07-04 13:03 UTC (9 hours ago)
(HTM) web link (www.economist.com)
(TXT) w3m dump (www.economist.com)
| svara wrote:
| 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
| exponentially [2]. A combination of Li-Ion battery (short-term),
| pumped hydro (medium-term) and hydrogen (long-term, i.e.
| seasonal) storage is probably how to smooth out the burstiness of
| renewable energy production eventually [3].
|
| When green hydrogen infrastructure is commonplace, the hydrogen
| can also be used to make synthetic jet fuel and feedstocks for
| the chemical industry.
|
| [0] https://en.wikipedia.org/wiki/Cost_of_electricity_by_source
|
| [1] https://www.cell.com/joule/fulltext/S2542-4351(19)30300-9
|
| [2]
| https://www.nature.com/articles/nenergy2017110/figures/1?pro...
|
| [3]
| https://www.sciencedirect.com/science/article/pii/S254243511...
| dmix wrote:
| 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 malaise of
| public projects adding significant delays/costs, which is
| hardly unique to Pakistan when it comes to major infrastructure
| in 2020.
|
| https://en.wikipedia.org/wiki/Quaid-e-Azam_Solar_Park
|
| Then there's the famous Solyandra which got half a billion in
| US tax payer money and flopped without ever being competitive
| price-wise: https://en.wikipedia.org/wiki/Solyndra
|
| Tesla's famous Australian battery factory only has enough to
| power 30k homes for about 1-2hrs each day. It was on-schedule,
| which is rare, and also makes money but scaling it up to
| millions of homes to make a real dent in coal would be much
| more challenging, especially sourcing enough lithium.
|
| I think it's safe to take any cheery prediction from green
| projects and add 1.5x time/production costs and/or minus 30% of
| the expected output.
|
| Note: I'm not trying to rain on the parade, I'm otherwise all
| for this stuff as long as it's realistic on a large scale.
| meditative wrote:
| Tesla's Australian battery was not for storage, it's for
| power quality.
| wlesieutre wrote:
| It's for both - 70% of capacity is for grid stability and
| the other 30% is for storing power when it's cheap and
| selling it back when it's expensive.
| walrus01 wrote:
| I'm honestly curious what is the big challenge with keeping
| large arrays of ground mounted panels clean in Pakistan. The
| prevailing wage for unskilled labor for a 6 day a week,
| 45-hour work week 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.
|
| With some basic equipment like rolling carts with sprayers
| and squeegees on extension sticks, how many individual
| 72-cell sized panels (1.99 x 0.99 meter size) can one person
| clean in one day? Multiply by probably 4 to 6 full time staff
| positions.
| zamfi wrote:
| Quoting the Wikipedia page cited above:
|
| > It required one litre of water to clean, each of 400,000
| installed panels. A total 15 days cleaning cycle required,
| 124 million litres of water enough to sustain 9000 people,
| while rain in Cholistan desert is rare and far between.
| Providing such huge amount of water in desert terrain,
| became a challenging and daunting task for management team.
| Besides, the manual cleaning methods allowed setting of
| dust before it was re-cleaned.
| kevinstubbs wrote:
| What about a fleet of automated drones/machines which
| clean the panels by blowing air? I don't know, but it
| seems like physically scrubbing the panels would take
| more machinery (heavier), more moving parts (break down
| more easily), and the scrubs themselves would have to get
| replaced & careful not to be abrasive (not sure how much
| the panels "care" about it though). These "dusters" could
| run off the excess power too. I read somewhere else in
| this thread that one problem was the solar park would
| occasionally over-produce - maybe the fleet works
| whenever there is an overproduction, or after a certain
| amount of time has passed (we _must_ clean them now and
| can't wait until the next time of overproduction).
| justinclift wrote:
| If you're going to clean things via physical automation,
| you could probably work out the energy cost involved
| ~reasonably well over time.
| riku_iki wrote:
| but maybe they can use seawater for cleaning?
| vlovich123 wrote:
| Would the salt be abrasive & damage the panels/coating
| decreasing efficiency?
|
| I would imagine another challenge is the transporation
| costs. The nearest fresh water source appears to be
| Sutlej River ~18 KM straightline. The nearest seawater
| source appears to be the Arabian Sea, ~800 KM
| straightline.
|
| The cost to a problem like this would never be labor as
| that can be trivially automated if it ever gets costly
| enough. Water is expensive at these scales.
|
| That being said, it's probable that there could be
| solutions here. Automated scrubber/blower might be able
| to get most of the efficiency back without the cost
| (whether integrated into the panel or a robot on a
| track). Could potentially use any water more judiciously
| too when needed (moisten a scrub rather than blasting it
| with water). Don't know enough about the project but I
| would hope the domain experts responsible for the project
| would have considered something I only thought about for
| 30 seconds & there are reasons that they don't do that.
| mdorazio wrote:
| This seems kind of like a bullshit excuse where they just
| didn't really want to fix the issue. There are a number
| of waterless cleaning systems that have been available
| for years, for example [1]. Additionally, why the hell
| would you throw away the water used for cleaning?
| Filtering the dust particulate out of the water is pretty
| straightforward (hell, you can go from muddy to fairly
| clean water with nothing more than a cotton t-shirt),
| then you reuse it to clean more panels. 1L/panel with
| even basic reclamation is ridiculous.
|
| [1] https://www.youtube.com/watch?v=wdidbRQaUEY
| ianai wrote:
| Agree. They could probably just have people walk around
| with blowers to blow the sand off.
| pfdietz wrote:
| And there are also many PV cleaning robots available. This
| is not self-driving car stuff, it's off the shelf
| technology.
| zamadatix wrote:
| 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 as well. By far the biggest costs seem to have been
| with corruption from choice of renewable source to choice
| of contractor vs operation of the actual installation.
| klipt wrote:
| How high does the dust go? Maybe they could cut down on
| cleaning by just building a wall around the power plant, or
| add some fans to keep the dust out?
| newacct583 wrote:
| Solyndra's failure had nothing to do with technology at all.
| They failed because Chinese manufacturers _undercut them in
| price_ , quite severely. Allegations of dumping (or fraud, on
| the other side) notwithstanding, what this says is that solar
| is actually much cheaper and more readily available than
| Solyndra's investors expected. And that's sort of the
| opposite of your point, no?
|
| Similarly the Tesla plant is doing exactly what it said it
| was going to do, when it was supposed to be finished, within
| the budget it had, and AFAIK is making money. You're
| asserting that it can't scale because it... worked?!
|
| As far as the Pakistani misdesign, yeah, I'm sure that's
| going to happen too. Nothing works perfectly.
|
| Nonetheless this seems like a pretty oddly constructed list
| of reasons why solar is "much worse in production". It seems
| to my eyes like it's doing much better than expected.
| walrus01 wrote:
| I don't disagree on the point that they were undercut in
| price. But they were also undercut in price because
| commodity normal PV panels composed of 156mm
| polycrystalline or monocrystalline cells (60 or 72 cells)
| are much cheaper to manufacture than the weird proprietary
| system they developed. They are also much cheaper to mount
| on large roofs (home depot/walmart warehouse sized) or on
| large scale 300kW+ ground arrays.
|
| Ordinary 60 or 72-cell panels are DEAD SIMPLE in their
| construction. It's a sandwich of a backing material,
| encapsulation for the cells and soldering, glass in front,
| with an aluminum frame and a junction box on the rear.
|
| Solyndra "panels" are fragile, hard to transport, hard to
| mount, everything about them was a pain in the ass.
| nappy wrote:
| You can't fund potentially breakthrough innovation and
| research and only get one tail of the distribution. It's
| a good thing, not a bad one, the the US government
| providers funding, and in this case, interest free loans
| for projects that sometimes fail.
| dgut wrote:
| Solar power is alive and kicking in Spain and increasingly
| more cost effective (removing the need of subsidies since
| 2018).
| toomuchtodo wrote:
| Spain just shuttered half of their coal capacity at the
| end of June 2020 partially due to this (also because of
| emissions requirements owners didn't want to meet), and
| intend to shutter the rest by 2025 (additional wind power
| and pumped hydro for storage is coming online in that
| time).
|
| https://english.elpais.com/economy_and_business/2020-06-2
| 9/s...
| FabHK wrote:
| Regarding [1], the article quotes production costs of USD
| 50/MWh for renewables, and USD 100/MWh for coal (graph 3).
|
| You/[1] is saying that with storage costs of USD 150,000 per
| MWh, renewables can be competitive? It doesn't compute, unless
| I misunderstand something.
| Retric wrote:
| 150,000$ / 3,000 charge cycles (~8.3 years) = 50$/MWh =
| 0.05c/kWh.
| wtallis wrote:
| I think that $150000 per MWh buys you a storage system you
| can use more than once, rather than being the cost per usage
| of the storage system. After a few years, the amortized cost
| drops below coal generation.
| imtringued wrote:
| Batteries last longer than one cycle...
| azdle wrote:
| Just from your numbers, it sounds like it's a good deal as
| long as you need to (grid) store less than 1/3 of your
| generated/consumed energy.
| jacquesm wrote:
| Hydrogen, to put it simply is a battery, not a fuel, and a
| relatively poor battery at that. For all the money dumped into it
| and the amount of research that has been done BEV is now
| generally considered the way forward. It also doesn't suffer from
| the problem that Hydrogen tends to go FOOF when you least expect
| it, and there isn't the pesky problem of Hydrogen embrittlement
| to deal with.
| [deleted]
| carapace wrote:
| Hydrogen is sexy but alcohol matches our existing context better.
|
| Small-scale alcohol fuel production integrated into regenerative
| agriculture farms is different from mass ethanol production.
|
| You can ferment anything that has starch or sugar, the leftovers
| from the distillation can be composted or fed to livestock. Most
| existing internal combustion engines can be modified to use
| alcohol fuel. And it's carbon-neutral.
| dredmorbius wrote:
| Feedstock is the problem here: there's simply not enough net
| primary productivity on the planet, and humans already
| appropriate ~20%.
|
| There are some marginal gains possible, but on the order of
| single-digit percentages of present fossil fuel consumption.
| _Maybe_ low double-digits.
|
| The US had a largely biofuel based transport system in 1900.
| Horses consumed 20% of all US grain production, the population
| was under 100m, and transport generally was a small fraction of
| today's values (or at least last year's) per capita: closer to
| 300 mi/yr, much of that walking, than 15,000.
| elago wrote:
| 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 amount of acreage--swamps, arid or sloped land, even
| rivers, oceans, and ponds--that the USDA doesn't count as
| cropland or farmland, but which is still suitable for growing
| specialized energy crops.
|
| Of its nearly half a billion acres of prime cropland, the
| U.S. uses only 72.1 million acres for corn in an average
| year. The land used for corn takes up only 16.6% of our prime
| cropland, and only 7.45% of our total agricultural land.
|
| Even if, for alcohol production, we used only what the USDA
| considers prime flat cropland, we would still have to produce
| only 368.5 gallons of alcohol per acre to meet 100% of the
| demand for transportation fuel at today's levels. Corn could
| easily produce this level--and a wide variety of standard
| crops yield up to triple this.
| dredmorbius wrote:
| 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, along
| the Pacific and Atlantic costs. It 's roughly 1,300 miles
| from San Diego, CA to Port Angeles, WA, and 1,800 miles
| from Homestead, FL to Lubec, ME. Dividing our 443,000
| square miles by those two added together, we find we'd have
| to extend our grow region some distance off-shore. That is,
| 143 miles off-shore. The full length of both coasts._
|
| _Or perhaps you 'd prefer to re-purpose the Gulf of
| Mexico. Its total area is about 600,000 mi2, we'd need
| about 3/4 of it dedicated to algae growth._
|
| https://old.reddit.com/r/dredmorbius/comments/2cvap7/the_in
| t...
|
| Tom "Do the Math" Murphy:
|
| https://dothemath.ucsd.edu/2011/11/the-biofuel-grind/
|
| https://dothemath.ucsd.edu/2011/08/garbage-in-garbage-out/
|
| The late David MacCay's _Alternative Energy Without the Hot
| Air_ gives a comprehensive breakdown for the UK of
| alternative energy options. Again, the picture is bleak.
|
| https://withouthotair.com
|
| The takeaways are _we use a lot of energy_ and _there are a
| lot of us_.
| philipkglass wrote:
| 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 consumption.
|
| It's actually much worse than that, because the energy
| content of a gallon of ethanol is only about 65% the energy
| content of a gallon of oil:
|
| https://en.wikipedia.org/wiki/Energy_density#Tables_of_ener
| g...
|
| This much ethanol would only provide 48% of the energy
| currently consumed by oil based transportation.
|
| It's actually much worse than that because most crop land
| is already used to grow _crops_ eaten by animals and
| people. If we feed all the crops to transportation
| machinery, others will go hungry.
| carapace wrote:
| You're right that you couldn't replace every use of fossil
| fuel, but for a large portion of non-industrial use I think
| it's a very valid and viable strategy.
|
| The key is that you're producing the alcohol as part of an
| integrated system of production that mimics Nature. You have
| a farm that requires no inputs (of fertilizer, and in some
| cases no irrigation) that produces multiple crops per year.
| ("Syntropic" agriculture, "Permaculture", food forests) You
| can grow sugar beets, yams, sugar cane, or starchy plants
| such as potatoes, certain kinds of reeds, tubers, etc.
| directly for fermentation, or use scrap fruit from the
| orchards, etc. Literally anything that has starch or sugar
| can be used as a feedstock. Scrap dough from a (doughnut)
| bakery.
|
| The leftovers from the fermentation and distillation aren't
| wasted: you feed them to livestock. Because it's a yeast
| culture there's _more_ protein in it now than it had before.
|
| So your farm produces fruits and veggies, meat, and alcohol
| fuel.
|
| (I'm getting all this from
| http://alcoholcanbeagas.com/sitemap )
| pfdietz wrote:
| 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.
| mdavis6890 wrote:
| I wish I'd stop hearing about Hydrogen as a fuel source. It's
| not. It's just a battery, and should simply be compared to other
| types of batteries, like Li-Ion. Maybe Hydrogen fuel cells are
| better batteries, maybe not.
|
| But it's still just a battery, and needs to be charged from the
| electric power grid (by using the electricity to separate
| hydrogen from water), just like any other battery would.
| boublepop wrote:
| The defining difference between fuel-cells and batteries is
| that fuel-cells don't need to be "recharged" as in running an
| electrochemical reaction in reverse, they just need you to
| change the fuel.
| acidburnNSA wrote:
| But the fuel was charged from another source in fuel cells
| too. You don't mine hydrogen. The energy carrier point
| remains. The primary energy will be from gas, oil, coal,
| nuclear, hydro, solar, wind, geothermal, biomass, or tidal.
| tomxor wrote:
| Following Musk's thinking... i'd really like to see that energy
| density volume vs mass chart adjusted for average vehicle weight.
| i.e see the total system, engine, storage components and fuel
| converter etc.
|
| On that graph, compared to petrol, liquid hydrogen appears to be
| about 4x larger by volume but interestingly only 2/5ths of the
| weight.
|
| The electric motors are lighter sure, but then what about the
| mass and volume of the compressed storage tank and the fuel cell
| itself? difficult to know if it starts to gain on IC engine
| again. lots of questions that make that graph feel pretty
| meaningless.
| ecpottinger wrote:
| Not once you include the storage tanks.
| tomxor wrote:
| That's my entire point.
| [deleted]
| mrtnmcc wrote:
| Something practical not mentioned here is that the proton
| exchange membrane in fuel cells generally degrade in a few years
| and need to be replaced. This is a major expense. Degradation is
| accelerated if the hydrogen (fuel) or oxygen (from environment)
| are not pure.
| xivzgrev wrote:
| As soon as I read hydrogen stored in a tank - did anyone else
| think potential to explode in an accident?
| admax88q wrote:
| Hydrogen production is almost entirely produced from fossil fuels
| currently. Its not really a low carbon energy source unless
| electrolysis can be made much more efficient.
|
| Its a shame this article didn't examine the production side of
| hydrogen.
| reyoz wrote:
| A recent report [1] looked at the efficiencies of generating
| hydrogen at a waste water treatment plant to lower production
| costs. The WWTP provides the water and uses the oxygen that is
| also produced by electrolysis to increase the efficiency of the
| biological treatment process vs air. Some of the electricity
| for the electrolysis can also be sourced from biogas produced
| by the WWTP.
|
| [1] https://www.jacobs.com/sites/default/files/2020-06/jacobs-
| ya...
| helsinkiandrew wrote:
| Isn't the last 1/3 of the article about the differences between
| grey, blue and green hydrogen?
| admax88q wrote:
| Ah that's my fault then. About 2/3 of the way through the
| article something loaded or shifted as nobody can resist the
| urge to highjack scrolling and I lost the rest of the text so
| I stopped reading.
| ced wrote:
| From Wikipedia:
|
| _The lower the energy used by a generator, the higher its
| efficiency would be; a 100%-efficient electrolyser would
| consume 39.4 kilowatt-hours per kilogram (142 MJ /kg) of
| hydrogen,[24] 12,749 joules per litre (12.75 MJ/m3). Practical
| electrolysis (using a rotating electrolyser at 15 bar pressure)
| may consume 50 kW[?]h/kg (180 MJ/kg), and a further 15 kW[?]h
| (54 MJ) if the hydrogen is compressed for use in hydrogen
| cars._
|
| It's not great, but it doesn't seem unworkable. I can't read
| the article, but isn't the idea to use hydrogen tanks as a
| battery to smooth out the variability of renewables like solar?
| DaiPlusPlus wrote:
| How is that different from criticism of BEVs when they're used
| in areas with coal-based electricity?
| admax88q wrote:
| My understanding is moving electricity into a battery is much
| more efficient than using it to break water into hydrogen.
| hnick wrote:
| I don't think most people consider it an energy source, more so
| a battery or storage medium. And cheaper storage is an
| important part of the renewables story because local supply can
| be unpredictable.
|
| I saw this article earlier today along those lines:
| https://www.smh.com.au/environment/climate-change/alchemy-of...
|
| Supposedly this stores hydrogen metal hydrides cheaper than
| lithium batteries, whatever that means, but I'm not qualified
| to judge.
| dghughes wrote:
| There is a video on YouTube about Bob Lazar the area 51 guy.
| Only it's about how he uses solar and wind to break down
| water into oxygen and hydrogen. He stores the hydrogen as a
| metal hydride. The tanks are heated to release the hydrogen
| and it's used to power his car.
| goda90 wrote:
| The article does talk about steam reforming vs steam reforming
| + carbon capture vs electrolysis of water and the carbon cost
| and economics of each.
| jsilence wrote:
| The explosion limits of hydrogen are very wide. I do not want to
| live in a world with a widely deployed hydrogen infrastructure.
| Stuff is going to blow up. People are going to die. Disclaimer:
| chemical engineer, German University.
| MayeulC wrote:
| People said that about electricity, too. A lot of people died.
| Houses burned. Norms were changed regarding cabling and
| earthing. Hopefully, whatever we decide to adopt as a
| technology will come with adequate safety norms.
|
| While only tangentially related, a lot of people think about
| the Hindenburg accident when talking about either hydrogen or
| dirigibles. But those contain less fuel than an airplane, at
| least in terms of energy. And 35 people died, around a third.
| To contrast with airliner accidents. But it sure left a mark on
| collective psyche. And I agree that hydrogen is incredibly
| volatile and explosive, which isn't a good fit for every
| application.
| kumarski wrote:
| Okay, going to chime in here because this is categorically wrong
| on so many fronts.
|
| Tldr: Impossible for civilization to make an instantaneous non-
| gradual switch to hydrogen fuel cells.
|
| People like Hydrogen because they're hyped about how it is:
|
| - Clean
|
| - Plentiful
|
| - Emission-less
|
| Hydrogen is difficult to handle.
|
| - Unwieldy as a gas
|
| - Boils at 20 degrees F/ - 6 degrees C / ~420 Kelvins
|
| - Tough to maintain at a high pressure.
|
| To go 300+ miles or ~480km or more on hdyrogen is ugh tough.
|
| H - 120 MJ/kg
|
| Gasoline - 44 MJ/kg
|
| Volume wise, ugh.
|
| H- 8 MJ/L
|
| Gasoline - 32 MJ/L
|
| You need ~5-10 kilograms of H2 to deal with light duty vehicles.
|
| Compressing the stuff is annoying.
|
| Training and retraining all the gas station attendants to deal
| with cryogenic materials is no small undertaking.
|
| There's 100K gasoline/diesel stations in the USA.
|
| Very special handling for hydrogen.
|
| Hydrogen penetrates metals.
|
| Makes metals the enemy and things can wear down unexpectedly.
| Scary stuff. Preventative maintenance is complicated.
|
| Gasoline has ~4x-8x the kwh per a gallon to compressed hydrogen
| fuel. (my calculation might be a bit off, but not that far off.)
|
| Pumping hydrogen into a vehicle is done slowly from my
| recollection.
|
| Hydrogen's explosion risk is extreme, the spark from the leak
| could cause it. eekkkkk.
|
| Hydrogen's flames are invisible. It's a pale blue flame that's
| difficult to see during the day.
|
| People might come back and say there's progress with magnesium
| adn/or carbon nanotubes or other things, but they're all meh and
| don't scale.
|
| Hydrogen has a shitty power to mass ratio. It escapes
| independently/leaks out easily without you knowing. It's
| dangerously explosive!
|
| It emits lots of CO2 to make the stuff. CH4+O2 = CO2+2H2 Makes
| the whole thing seem like a pointless exercise.
|
| The efficiency of manufacturing hydrogen for fuel usage is
| probably like 10% to 30%. Can't imagine it being more than that.
|
| I'm not a Chem E though.
|
| To make a cryogenic pipeline system in the USA for H2 would cost
| $1T+
|
| Every year I get asked about Hydrogen, it's all BS.
|
| Any scientist that says it's highly viable has me wondering how
| much money they wasted on their degree.
| Erlich_Bachman wrote:
| Why does it need to be instantaneous? Who is even asking for
| instantaneous?
| BenjiWiebe wrote:
| Hydrogen boils at 20 degrees Kelvin, not Fahrenheit. That's
| -423 degrees Fahrenheit. If it boiled at 20 F, it would be a
| LOT easier to store and handle.
| hwillis wrote:
| > Volume wise, ugh. H- 8 MJ/L, Gasoline - 32 MJ/L
|
| In practice, hydrogen @10 kpsi/70 MPa is currently a bit over 1
| MJ/L when including the tanks. Gasoline is misleading as well,
| because a fuel cell is easily twice as efficient as a gas
| engine and up to 3x.
|
| Li-ion batteries are anywhere from .5 to 2.5 MJ/L, for
| reference. Thing is, volumetric efficiency is all but
| irrelevant for most applications. Even airplanes have huge
| amounts of empty space that could accommodate tanks; container
| ships would be less efficient but that's about it.
|
| > You need ~5-10 kilograms of H2 to deal with light duty
| vehicles.
|
| 5 kg will take a Toyota Mirai over 300 miles.
|
| > Training and retraining all the gas station attendants to
| deal with cryogenic materials is no small undertaking.
|
| This is not a thing. Attendants don't need to do anything with
| cryogenic anything.
|
| > Hydrogen penetrates metals. Makes metals the enemy and things
| can wear down unexpectedly. Scary stuff. Preventative
| maintenance is complicated.
|
| This is an issue when you're trying to build electron
| microscopes, not when you're fueling cars. The diffusion rate
| of hydrogen is negligible for everyday purposes like safety.
| Certain parts need to be designed to avoid embrittlement, but
| it's a minor problem- embrittlement is only really an issue at
| VERY high temperatures. If the steel isn't glowing, it's a
| minor issue, and for most other metals it's even less of an
| issue.
|
| > Pumping hydrogen into a vehicle is done slowly from my
| recollection.
|
| It's as fast as a highway pump, and often slightly faster. It's
| pretty hard to pump _slowly_ when 10 kpsi is involved, after
| all.
|
| > Hydrogen's flames are invisible. It's a pale blue flame
| that's difficult to see during the day.
|
| Typically it just explodes, unfortunately. Hydrogen is always
| at such high pressure that it spreads out rapidly and sustained
| flames are very unlikely, and then there's the fact that the
| energy density causes things to break.
|
| > The efficiency of manufacturing hydrogen for fuel usage is
| probably like 10% to 30%. Can't imagine it being more than
| that.
|
| Commercial processes are ~60% and non-commercial are above 80%.
| DaiPlusPlus wrote:
| What is your opinion of Toyota's hydrogen storage system for
| cars? It seems to tick all the boxes.
|
| (I just assume Toyota isn't going big on the Mirai for the same
| reason Ford and GM still only pay lip-service to BEVs: they
| don't want to upset their dealer network too much)
| threatripper wrote:
| Hydrogen might make some sense for long haul trucks. Then you
| need fewer refueling stations on only the major routes. You
| could also generate the hydrogen locally by using electricity.
|
| Alternatively you could equip the trucks with batteries and
| connect them to the electrical grid via overhead lines similar
| to trains for recharging. Combined with autonomous driving
| those trucks could go non-stop and leave the highway with full
| batteries.
| postingawayonhn wrote:
| Do we really need to convert long distance trucks to fully
| electric? Why not just work on hybrid trucks to increase
| efficiency and allow them to operate with zero emissions
| while in urban areas.
| ssmiler wrote:
| 2nd option exists and is called rolling highway ;)
| speedgoose wrote:
| I used to drive a hydrogen car once in a while a few years ago.
| It was nice to fill the car in a few minutes and get about 300km
| of range, but that was it.
|
| With the hydrogen you have so few refueling stations, they are
| very expensive, that range anxiety is a thing. To not improve
| things, reliability is very poor. My work had a hydrogen
| refueling station on its parking. It was often broken and
| actually a bit scary to walk past it. They eventually removed it,
| which was a good call. Another hydrogen station sharing the same
| design exploded a few months later. The hydrogen car sales
| dropped from not much to virtually zero since in the country.
|
| So to resume, hydrogen cars are expensive, refueling stations are
| expensive, the energy is expensive.
|
| Electric cars with large batteries are a much better solution to
| hydrogen cars IMHO. You can charge everywhere, the eletric grid
| is very will developped, the energy is cheap. The cars are also
| much more powerful thanks to the large batteries pack, it's
| useless but it feels nice.
| Gibbon1 wrote:
| I feel like the draw of hydrogen as a fuel source is that it
| doesn't disturb the current power structure which is based on
| control of oil and gas supplies. Countries have to constantly
| import oil and gas to power their transport networks. That
| requires those countries to pay in dollars (usually). Control
| that and you have them by the nose.
|
| Electrification completely upends that. A country that is self
| sufficient in energy can tell other countries to take a hike.
| amelius wrote:
| > Electric cars with large batteries are a much better solution
| to hydrogen cars IMHO.
|
| Electric cars are still very dangerous when they catch fire
| though. And the fires are very difficult to control. Especially
| in multistorey (or underground) car parks. And even more so if
| there are multiple EVs parked next to eachother.
| speedgoose wrote:
| Sure when the batteries burn it's a problem. But the
| batteries don't burn that often. For example, when a diesel
| car did burn inside an airport parking in Stavanger, many
| electric cars did burn as well but not their batteries.
| kolinko wrote:
| And gasoline cars aren't?
| darksaints wrote:
| Hydrogen may never be competitive with batteries for
| intermittently used passenger cars, but not all vehicles are
| intermittently used passenger cars. There is a lot of evidence
| that hydrogen can be competitive and potentially superior for
| vehicles which are used all day long, like taxis, delivery
| vehicles, etc.. And for continuous high power applications like
| maritime and aviation, batteries are so far from a realistic
| possibility that at best they are research projects. Batteries
| might work for ultra low range applications of trucking, like
| LTL and local delivery, but a lot of useful hauling capacity is
| given up by hauling batteries around.
| svara wrote:
| The article isn't about hydrogen cars and in fact points out
| that hydrogen cars have lots of problems.
| Ottolay wrote:
| I hate that most people just respond to the title and don't
| respond to the contents of the article.
| Erlich_Bachman wrote:
| Maybe the way forward for the hydrogen power is to tackle the
| power storage in the grid first. Yes, I know that it is not
| very efficient, but few solutions there are efficient and we
| need some solution if we are going to increase reliance on
| solar and wind. Maybe while hydrogen energy storage will take
| its place in the grid, the technologies will get developed
| further, up to theoretically a point where a hydrogen-based car
| will make more sense realistically. (For example availability
| of hydrogen itself, the price and the number of stations around
| will be more allowing of it.)
| jasonlaramburu wrote:
| When you consider the energy required to produce lithium ion
| batteries they are actually worse than fuel cells from an
| emissions perspective:
|
| "As an example, a 100kWh battery will give a potential range of
| 250 miles and, in order to produce that battery, it will take
| around 20 tonnes of CO2," he said. "A typical battery lasts for
| 150,000 miles, so that equates to around 83g/km of CO2. Then,
| when you take into account charging over that same distance,
| the same battery car will deliver 124g/km of CO2 over its
| lifetime."
|
| By comparison, Auto Express says that a recent study found that
| a Toyota Mirai hydrogen fuel cell car produces around 120g/km
| of CO2 over its lifetime when the manufacturing process is
| taken into account. But if hydrogen were to be produced by
| renewable energy, that figure could be reduced significantly."
|
| Source: https://www.theweek.co.uk/electric-
| cars/101196/hydrogen-fuel...
| sorenbs wrote:
| Sounds like you need to follow Auke on Twitter :-P
|
| He has literally spent the last five years debunking this
| nonsense. Here's a thread from just 5 hours ago:
| https://twitter.com/AukeHoekstra/status/1279359481177083904
|
| TL;DR: These comparisons always use too much energy for
| battery production, too high efficiency for gasoline cars,
| and fail to take into account that the grid is rapidly
| decarbonising, even in backwater countries like USA. Your
| source claims 20 tonnes for battery production, but reality
| is around 6 tonnes and falling due to grid decarbonising.
| jasonlaramburu wrote:
| Those figures cited by Auke are self-reported by Tesla. Not
| saying that invalidates them but important to consider
| context. It would seem that emissions associated with
| battery production vary greatly depending on geography and
| mix of energy sources. Eg in Germany, emissions from Model
| 3 battery production are estimated at 11 to 15 tonnes per
| vehicle: https://eufactcheck.eu/factcheck/mostly-false-
| electric-cars-...
| sorenbs wrote:
| The 11-15 Tonnes come from the study that you referenced
| page is disputing?
|
| There is a persistent narrative in Germany that diesel
| cars are better for the environment, and your comment is
| playing into that. This narrative is wrong and damaging.
|
| Why are you doing this?
| jasonlaramburu wrote:
| The paper didn't dispute anything. It made the point that
| emissions from battery production depend on the local mix
| of energy sources. At the time of publication, Germany
| got 1/3 of its energy mix from coal, hence batteries
| produced there have a higher emissions profile.
|
| What am I 'doing' exactly, pointing out a fact that there
| is no 'free lunch' when reducing emissions?
| mcot2 wrote:
| 1.) There is already tech in development for batteries to
| last 1M miles.
|
| https://www.autoblog.com/2020/06/11/catl-million-mile-
| batter...
|
| 2.) Energy required to produce the batteries will eventually
| shift to zero emission sources.
|
| 3.) Materials can be recycled from the battery even after its
| million+ mile use.
|
| It's hard to overcome the energy required to produce hydrogen
| plus the bad efficiency of fuel cells compared to
| batteries/electric motors.
| jasonlaramburu wrote:
| Green energy will decarbonize hydrogen production as well.
| kolinko wrote:
| How are those emissions calculated? Is there anything in the
| process that needs to generate co2? (like in concrete, where
| production of concrete generates co2 by itself).
|
| If this co2 is due to electricity/transportation cost then
| the problem will solve itself with more electricity from
| green sources.
| jasonlaramburu wrote:
| Couldn't you make the exact same argument about hydrogen?
| As renewables grow the emissions associated with hydrogen
| production will come down too.
| sorenbs wrote:
| Sure, but the total system loss for hydrogen is much
| higher, so unless renewable electricity becomes free,
| batteries win on tco.
| Ottolay wrote:
| The lithium and other metals in that battery though can be
| recycled at its end of life. Subsequent batteries will have
| lower life cycle carbon footprint.
| Dumblydorr wrote:
| The issue of charging was also there with BEVs, until Tesla
| straight up built a huge network of superchargers. The players
| in hydrogen say they will do the same. But for personal
| vehicles, hydrogen won't math out, it's greatest advantage is
| its energy density for trucks.
|
| It's for long range trucks that we will see hydrogen first.
| Green hydrogen will act as energy storage, big renewables grids
| can dump excess into green hydrogen and thus avoid curtailment.
| Then, you replace heavy duty trucks, which need to be able to
| not have heavy batteries, with fuel cell trucks, and you build
| out 1000 large hydrogen stations across the transit network.
| henrikschroder wrote:
| > The issue of charging was also there with BEVs, until Tesla
| straight up built a huge network of superchargers. The
| players in hydrogen say they will do the same.
|
| The fact that EV players actually delivered and built
| charging networks should offer plenty of proof as to which
| technology is more viable.
|
| It took decades to build out the network of gas stations
| across countries. The reason it took much less to build out
| charging networks is because the power grid already existed,
| we already had 95% of the infrastructure for delivering the
| "fuel" for EVs.
|
| But hydrogen companies are still talking as if it's super
| simple to build out a hydrogen infrastructure. Why would that
| not take decades as well? And that's assuming there was some
| kind of massive consumer demand for hydrogen vehicles, which
| there just isn't.
| Dumblydorr wrote:
| You're forgetting decades of lithium ion buildout for
| personal devices. Hydrogen needs time to scale, batteries
| have been doing so for decades. Tesla was able to build
| dozens of chargers because others had invented and scaled
| great cylindrical batteries and they had straubel who knew
| how to make great packs.
| Certhas wrote:
| Hydrogen to avoid curtailment is key. Hydrogen is super
| inefficient. But if you would be dumping the energy otherwise
| that doesn't matter.
| darksaints wrote:
| Efficiency isn't, and never has been, a deal breaker. There
| are hundreds of millions of vehicles that have been built
| with efficiency levels far lower than the best in class for
| ICE, and they're still used. Efficiency is just one factor
| of many that contribute to cost of ownership and operation.
|
| Even then, fuel cells are not super inefficient. At the low
| end of efficiency, PEM fuel cells are already more
| efficient than the vast majority of current generation ICE
| vehicles. And with SOFCs with novel heat recuperation
| technologies, 85-90% efficiencies are already achievable.
| RobertoG wrote:
| Maybe ships is an even better fit than trucks?
| hwillis wrote:
| Trucks are explicitly limited by weight, ships are somewhat
| limited by volume. Container ships especially need to be
| loaded way up because the cargo is less dense than eg crude
| oil.
|
| Heavy trucks are also a much bigger issue than
| international shipping, which is only ~2% of global GHG.
| 6.7% of US GHG emissions come from medium and heavy duty
| trucks, or 23% of emissions due to transportation.
| dylan604 wrote:
| Would it be though? I understand ships are heavy polluters,
| but the areas they are polluting in are much larger than
| trucks in traffic in cities. Cities are so much more dense,
| and you can see that effect in satellite imagery.
| Eric_WVGG wrote:
| I was wondering the same thing, from a density perspective.
| And similarly for airplanes.
|
| As planes and boats expend fuel, they get lighter, so less
| fuel is needed to move the second half of the journey, and
| less for the last quarter, etc. That "bonus" doesn't work
| out with batteries, you need to move all the weight for all
| the journey. The energy density of batteries, to my
| understanding, just doesn't add up correctly for boats or
| most airplanes.
|
| What I would like to know is, wouldn't a hydrogen-powered
| boat or plane not only have a similar calculation on how
| much fuel is needed, but also (in the case of boats) be
| even cheaper to move because its fuel payload is lighter
| than water? Water 997kg/m3 vs liquid hydro 71kg/m3, also
| gasoline 783kg/m3, sounds like a nice bonus for jumbo jets
| too. (I am NOT a physicist or mechanical engineer)
|
| Gasoline-powered sea vessels are terrible polluters,
| incidentally, accounting for 18% of all air pollution.
| Between the air pollution benefits and possibility of the
| vessels being so much more fuel efficient, it seems like
| hydrogen would be a benefit even if the production isn't
| completely clean.
| dredmorbius wrote:
| _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 petrol
| engines do exist). Much of the pollution is in the form
| of particulates and sulfer emissions. You can actually
| see major shipping routes on atmospheric sensing maps by
| SO2 emissions:
|
| https://earth.nullschool.net/#current/chem/surface/level/
| ove...
|
| As long-term risks these are ... somewhat minor as these
| contaminants settle out quickly: in days to months rather
| than centuries to millennia for CO2 and methane. Not
| great for respiratory health, but not the long-term
| planetary risk fossil fuel combustion overall is.
| MayeulC wrote:
| > 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 weight of their fuel: they need to carry it up, when
| they have the most. This could actually be a game-
| changer, I think.
|
| That could also be exploited: raise the battery when it
| is charged, have it gain weight, generate electricity
| while lowering it. Perpetual motion doesn't exist, of
| course. But gaining a bit of extra mileage is
| theoretically possible here :)
| eqvinox wrote:
| Or non-electrified railways. A modern "diesel" engine is
| actually diesel-electrical anyways, since curiously
| diesel->electric->movement is more efficient than straight
| diesel->movement. For a hydrogen-electrical engine you
| could presumably stick one or two special tanker cars
| behind it with the necessary tech to keep it cool. The
| engine could even be dual-mode and use electrification
| where available (like this one already does for diesel:
| https://en.wikipedia.org/wiki/Bombardier_ALP-45DP )
|
| For comparison, an ES44AC
| [https://en.wikipedia.org/wiki/GE_Evolution_Series] carries
| 18900l of diesel (weighing 15.7 tons), which at 38.6 MJ/l
| rounds to 730GJ of energy. Hydrogen seems to have a
| specific energy of 120-142 MJ/kg, using the conservative
| 120 that's about 6.1 tons of hydrogen, but now for the
| volume... https://www.energy.gov/eere/fuelcells/hydrogen-
| storage lists "0.03kg/l" as a "system target"... so 6.1
| tons is 203,333l. That's 2 conventional tank cars (but
| those don't have any cooling or pressurization systems.)
|
| (Of course this assumes the efficiency of
| diesel->electrical and hydrogen->electrical to be similar,
| which is not the case.)
|
| P.S.: https://en.wikipedia.org/wiki/Hydrail &
| https://www.bbc.com/future/article/20200227-how-hydrogen-
| pow...
| bogdanu wrote:
| You can't charge your hydrogen car at home, not to mention
| without any special and expensive equipment.
| jiofih wrote:
| It pays off to read the comment fully before replying to
| it.
| bogdanu wrote:
| My reply was mostly meant only for the first 2 sentences,
| except the trucking part.
|
| I was trying to evidentiate that charging stations built
| by tesla supplement home charging or any normal outlet.
| It's a bit different than building a network of
| superchargers because the demand would be a lot higher
| because a hydrogen powered car will be fully dependent of
| those specially built charging stations.
|
| The main idea is that a BEV owner doesn't need a
| supercharger station to use his car. Sure, it'll be nice,
| but not mandatory; let's not forget that not everybody
| lives in US or W. Europe where the network is more
| developed.
| chefandy wrote:
| Can't gas up at home either. By my reckoning, if there was
| a huge network of hydrogen stations that should do the
| trick.
| bogdanu wrote:
| Nope, but you can with a BEV. A SMB could afford to offer
| a low electric charging station; heck, software companies
| could offer the possibility to charge their employee cars
| for free as a perk; even a normal outlet would be enough,
| 8-9 hours would be more than enough for charging.
|
| Maybe the local administration could offer some
| incentives to companies that have this.
| darksaints wrote:
| Maybe not with current production cars, but there is plenty
| of available technology that _would_ allow for it. Fuel
| cells can be reversible...meaning the same cell that takes
| hydrogen and oxygen and turns it into electricity and
| water, can do the reverse: take water and electricity and
| turn it into hydrogen and oxygen.
| hwillis wrote:
| And you always have full (trip) range every morning with an EV.
| Yes, filling up in 5 minutes is better than 20. Never needing
| to fill up is even better.
| [deleted]
| Erlich_Bachman wrote:
| > Never needing to fill up is even better.
|
| And which technology allows for that? The cars "running on
| water" that new age alien enthusiasts are always on about?
| UnpossibleJim wrote:
| There's also the work on wireless charging via the roadway,
| itself. No, it isn't working right now but it's in its
| infancy. Only the very first prototypes have been rolled
| out, and they don't wear well, admittedly. Solutions are
| being worked on.
|
| Technology is only limited by your imagination and your
| ability to problem solve. =)
| fennecfoxen wrote:
| Capital expenditure, in a system where resources are
| finite and trade-offs must be made, is a notoriously
| tricky problem to solve.
| freehunter wrote:
| One of the HN guidelines is to assume good faith when you
| respond to a comment.
| aae42 wrote:
| i think he's referring to those who have the ability to
| charge their car at home, effectively never having to visit
| actual charging station
| Animats wrote:
| If you want an hydrogen-powered car, buy a Toyota Mirai. They've
| been on sale in California since 2016. There are a few hydrogen
| stations where you can fill it. 5 minute refuel, about 300 mile
| range. (400 miles in the 2021 model.) The first three years of
| hydrogen are included with the vehicle purchase. Vehicle price
| about US$60K. (Expected to be higher for the 2021 model.)
|
| Total US sales in 2019: 1502.
|
| It's just not selling.
| userbinator wrote:
| _There are a few hydrogen stations where you can fill it._
|
| ...and that 's the problem. Gasoline, diesel, and electricity
| are all far easier to find than hydrogen.
|
| (Electrolysis is also extremely inefficient, for those who
| might be wondering.)
| threatripper wrote:
| Hydrogen has an efficiency problem. You need to convert other
| forms of energy to hydrogen at a loss. Then you need to store it
| and transport it, which is costly and may impose quite some
| energy cost for cooling or compression. Then you need to convert
| it back to electricity, also at a loss. If you start at
| electricity, the electrical grid and batteries would be much more
| efficient. If you start at oil or gas, you could use convention
| ICEs and get comparable overall efficiencies. For them transport
| and delivery is a solved problem.
|
| Hydrogen fuel cells are clean where you use them. But so are
| batteries. Inner cities could be kept cleaner using either. Inner
| city traffic is mostly short range, so batteries are at an
| advantage.
|
| Batteries have a rare earth problem. But so do Hydrogen fuel
| cells. There is work to reduce it for both technologies.
|
| Hydrogen fuel cells have a problem with varying loads. You would
| use additional batteries in cars to supply peak demand when
| accelerating or store braking energy. For comparable weight,
| range, and price you could replace all hydrogen technology with
| more batteries. Those bigger batteries would also wear out slower
| because the power demand per cell is lower.
|
| So, when would hydrogen make sense? I think only if you don't
| care for efficiency. When you have so much electrical power that
| it costs you nothing and is available at least a few hours every
| night. Hydrogen would do well in a combination with large scale
| nuclear fission/fusion. It could take decades until we get there
| if we ever go that route.
|
| I see that, as batteries become less and less expensive, the
| niche where Hydrogen could have good advantage is getting smaller
| and smaller. However you twist and turn it, either oil&gas or
| batteries have the advantage.
| pfdietz wrote:
| > Batteries have a rare earth problem.
|
| NiMH batteries do, but who is using those?
| SV_BubbleTime wrote:
| > So, when would hydrogen make sense?
|
| All production issues aside, aviation makes sense to me. Planes
| are only filling at known stops, the weight is superior to our
| best batteries, and the transition from fossil fuel to hydrogen
| jets should be easy.
|
| As for as long haul trucks, I can kinda see it, maybe, still a
| lot of storage, production, efficiency issues. Weight isn't
| nearly the same concern as it is for aviation.
|
| For cars, yea, I don't see it.
| unchocked wrote:
| And batteries have a scaling problem - hydrogen complements
| them nicely for long term storage. When energy is free, make
| hydrogen and store it in a tank (or in a salt cavern, as the
| article describes).
| GhostVII wrote:
| Electricity has a transmission problem though - there are some
| parts of the world with lots of clean energy, which we can't
| fully take advantage of because we can't transport electricity
| that far. Hydrogen allows us to use that clean energy to power
| cars in other parts of the world, since you can produce
| hydrogen in those places and then ship it to places without
| much clean energy. Also you can presumably stop and start
| hydrogen production as electricity demand changes (ex. Only
| produce it on sunny windy days where there is excess
| electricity) allowing you to shift the demand curve more easily
| than with electric cars.
| Gibbon1 wrote:
| I skimmed this
|
| http://large.stanford.edu/courses/2010/ph240/harting1/
|
| Appearances is that losses in transmission lines are a few
| percent per 1000km. Across the US is about 4000km so you'd
| lose a little under 20%.
| mrpopo wrote:
| 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.
| VBprogrammer wrote:
| One interesting approach is to convert the hydrogen again
| into ammonia (nh4). It's easier to store and is a very
| useful industrial feedstock in its own right.
| dehrmann wrote:
| I don't buy that hydrogen transport could ever be more
| efficient than shipping high-voltage electrons over copper.
| atombender wrote:
| I like this diagram from Volkswagen visualizing the energy loss
| at every step for hydrogen versus BEV:
|
| https://images.hgmsites.net/lrg/hydrogen-vs-electric--volksw...
|
| This image (don't know the source), which includes oil and
| coal, is also a good visualization:
|
| https://i.imgur.com/Wuhnlvu.png
|
| Even simpler:
|
| https://pbs.twimg.com/media/DPkaz0nX4AAcr_v.jpg
| dmckeon wrote:
| With regard to
| https://pbs.twimg.com/media/DPkaz0nX4AAcr_v.jpg if the
| capture and separate elements can be decentralized, then
| distribution and one storage phase are eliminated.
|
| In other words, if a refueling station can do solar or wind
| capture and electrolysis on-site, the economics are better.
| This would be unlikely for stations in urban or high-density
| areas, but for rural and suburban locations it might be a
| win.
| jepler wrote:
| 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 these function
| in suburban to urban settings? Would they be accepted by
| the public? In the US, siting rules are a mess, but one
| example I found called for 2500 feet (760+m) distance to
| property line and 1.5 times turbine height to overhead
| utility lines. (NCSL, 2016)
|
| Given these fairly large size requirements, unless I
| slipped some decimal points, it doesn't seem likely to work
| out.
|
| https://www.quora.com/How-many-kWh-will-1-sq-meter-of-
| solar-...
|
| https://cdn.ymaws.com/www.renewableuk.com/resource/resmgr/D
| o...
|
| https://www.ncsl.org/research/energy/state-wind-energy-
| sitin...
| tuatoru wrote:
| 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 climate or unfriendly (steep or unstable)
| terrain. All of which drive up maintenance costs or make
| the land also unusable for energy production.
|
| There are no good solutions apart from the one that coal
| companies astroturfed us into nearly banning in the
| 1960s.
| dehrmann wrote:
| How efficient is electrolysis compared to making
| hydrocarbons?
| mongol wrote:
| I would like to have seen more elaboration on transmission
| losses in the power grid. For example, if we imagine solar
| cells in Sahara generating energy for Europe, is power grid
| transmission feasible or does hydrogen look better in
| comparison?
| Gibbon1 wrote:
| I linked a paper talking about that. Losses are likely on
| the order of 5% per 1000km. I would think long distance
| transmission lines could transmit power both east and west
| which solves some of the time shifting issues. And south to
| north which solves some of the issue with low irradiance
| during the winter at high latitudes.
|
| AKA Germany would probably be better off investing solar
| farms in southern Spain and connecting via long distance
| transmission lines. Only 1600km or so. Also consider sunset
| is an hour later in south west Spain.
| sacred_numbers wrote:
| The problem with generating power in the Sahara for use in
| Europe has little to do with transmission losses and much
| more to do with the capital cost of building high capacity
| power lines over thousands of kilometers. There's also the
| cost of protecting those lines, since they would have to
| pass through several different countries that are not
| always politically stable.
| pkphilip wrote:
| There are other ways of generating electricity apart from
| electrolysis. For example, from food waste through yeast and
| other methods. Yes, there is some energy being used but you are
| talking about material which would go waste anyway:
|
| https://fuelcellsworks.com/news/a-simplified-way-to-turn-foo...
|
| First: Energy density The primary advantage of hydrogen is
| energy density. Though Li Ion and other technologies have
| improved considerably, they are no where near the energy
| density of fossil fuel technologies and therefore vehicles
| which use these batteries will have to carry huge weight of
| batteries to get better range. With Hydrogen that is not a
| problem.
|
| Second: Storage There has been huge advances in the safe
| storage of hydrogen - from the use of nanoporous carbon for
| storage
| https://www.sciencedirect.com/science/article/pii/S100200711...
|
| to the use of LOHCs (Liquid Organic Hydrogen Carriers) that is
| aromatic liquids to store hydrogen instead of storing it as gas
| or liquid hydrogen:
| https://www.chemistryworld.com/features/hydrogen-storage-get...
| ncmncm wrote:
| Hydrogen's high density of available energy per unit mass is
| the key to identifying where it is most potentially useful.
|
| Simply, it is by far the best of all possible aircraft fuels.
|
| Its one major disadvantage for this, as for most uses, is its
| low mass density: it needs more room than diesel to store
| enough to be useful. The tanks need to be bigger, and either
| strong enough to contain high pressure, or well-enough
| insulated to keep it liquid.
|
| Current aircraft store fuel in wing tanks not roomy enough
| for hydrogen. The most practical hydrogen-fueled aircraft
| would probably have a shape more like a lifting body than a
| submarine with skinny wings sticking out. So for best
| efficiency, we might need new airframes, but just using
| hydrogen yields major improvement. To oversimplify, the plane
| doesn't need to lift so much weight of fuel to cruising
| altitude, or carry it halfway across the world.
|
| Tankage has improved radically in recent years with the
| development of aerogels, which make practical carrying liquid
| hydrogen that need not held be at high pressure, so can be in
| tanks that conform to an aerodynamically-practical shape.
| (Other sophisticated storage methods increase weight, so are
| more practical on the ground.)
|
| Hydrogen is tricky to store for long or in large amounts, so
| the best way to use it is to produce it on demand where it is
| needed. A major airport would be a good place to produce it,
| as it could be piped directly into aircraft and used
| immediately. All the airport would need is water and power.
| Power can be collected by wind and solar over a wide area,
| delivered by transmission lines. The amount of water needed
| is negligible.
|
| Producing hydrogen would also yield plenty of oxygen, which
| might just be vented; but by carrying liquid oxygen, aircraft
| could fly higher, faster, and more efficiently, or at least
| get to cruising altitude more quickly. As electric power
| continues to get cheaper, uses for it such as liquifying
| oxygen along with hydrogen get more attractive.
|
| The first use will be in long-haul craft operating from a few
| major airports. It is possible that current large aircraft --
| 747s, 777s, A380s -- could be converted, by using some of
| what is now cargo space for tankage, and replacing fuel pipes
| and pumps and, quite possibly, engines. It would be a big
| job, made attractive mainly by the extreme cost of qualifying
| new airframe designs.
|
| The lost cargo space would be made up easily by the much
| larger weight capacity, as tens of tons less weight of fuel
| is needed. Cargo aircraft today often fly half-empty so as
| not to exceed their takeoff weight limit.
| nanomonkey wrote:
| Pure oxygen can also be used in the pyrolysis phase of
| gasification, turning waste organic matter into syngas
| (Carbon monoxide and Hydrogen gas), as it produces a more
| pure fuel then using air alone (which is 60% inert
| nitrogen).
| xyzzyz wrote:
| > For example, from food waste through yeast and other
| methods.
|
| How is it better than generating biogas from biomaterial,
| something we already do at industrial scale? What's the
| advantage of biohydrogen over biomethane?
| weswpg wrote:
| isn't methane much worse for the environment than
| generating power from hydrogren?
| ncmncm wrote:
| 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.
| godelski wrote:
| 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.
| xyzzyz wrote:
| If you generate the methane from biomass, and then burn
| it all without leaking any, I can't see how it can be in
| any way worse for environment than biohydrogen.
| cultofmetatron wrote:
| sounds like Iceland would do well to export hydrogen from
| electrolysis
| speedgoose wrote:
| Transporting hydrogen is expensive. It also has a tendency to
| leak.
| Erlich_Bachman wrote:
| > It also has a tendency to leak.
|
| But I mean, that has to be a limitation of current
| technology, right? There has to be engineering solutions
| that we can devise to make it as safe statistically as for
| example gasoline transport?
| marcosdumay wrote:
| > But I mean, that has to be a limitation of current
| technology, right?
|
| Not much. Hydrogen has a tendency of assuming a form that
| no material can hold.
|
| People have been working on chemical storage, but the
| efficiency always suffer.
| dredmorbius wrote:
| No, it's not just a matter of technology, or at least not
| in ways that are readily addressable. Hydrogen molecules
| are so small that the simply pass through solid matter as
| if it were loose-weave cloth. Worse, it embrittles most
| metals.
|
| And the leaked gas, especially if in an enclosed space,
| is flammable or explosive over a very wide range of
| concentrations.
|
| Long-term storage, transport, and use, at scale, is
| hugely problematic.
|
| https://www.sciencedirect.com/topics/engineering/hydrogen
| -mo...
|
| https://en.wikipedia.org/wiki/Hydrogen_embrittlement
|
| https://www.sciencedirect.com/topics/engineering/hydrogen
| -ex...
| dehrmann wrote:
| 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).
| dredmorbius wrote:
| 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/com
| ments/22k71x/us_navy...
|
| Others:
| https://old.reddit.com/r/dredmorbius/search?q=fischer-
| tropsc...
|
| The main development since has been Foghorn, a Google
| (Alphabet) project attempting to develop the technology.
| It failed.
|
| https://x.company/projects/foghorn/
| Xylakant wrote:
| Hydrogen has the nasty property of leaking through many
| materials, including metals. It also needs to be kept
| extremely cold. Both properties make it much harder to
| transport and store. It's not clear that technology must
| exist that makes transporting and storing hydrogen as
| safe and economically viable as gasoline.
| ComputerGuru wrote:
| Even storage of helium has largely been solved, and that
| is far more tricky than hydrogen. It's just expensive.
| Xylakant wrote:
| Helium is inert and not prone to explode when it sees the
| first spark. Also, as you indicate: storing helium is
| expensive - it is only economically viable because there
| is no competing product and hence whatever the price for
| helium storage is, it will get paid.
| SV_BubbleTime wrote:
| Remind me but there is also no way to make new helium.
| It's not a renewable, is it?
|
| I thought it was only available as a byproduct of natural
| gas collection.
| occamrazor wrote:
| Safe probably yes. Economically competitive is much
| harder.
| thinkcontext wrote:
| Iceland exports renewable energy in the form of aluminum.
| They have the potential to develop more energy but it's
| controversial because of impact on the landscape.
| aitchnyu wrote:
| Aluminum is called congealed electricity due to the energy
| intensive manufacturing process and recycling is very
| economical.
| generatorguy wrote:
| What type of energy can they develop? Iceland is well known
| for their geothermal energy I wouldn't have thought that
| would have a huge impact on the landscape more than any
| other low rise industrial buildings.
| thinkcontext wrote:
| 70% of electricity is hydro, most of the rest is
| geothermal. On the consumption side about 70% is used for
| aluminum.
| Gibbon1 wrote:
| I ran into a fascinating paper published in the 1950's by a
| Norwegian group who ran a pilot plant to electrowin iron
| from iron-sulfide waste from a copper mine. They claimed
| something like 4-5 kwh per kg. Unlike electrowining
| aluminum it's a room temp aqueous process. My thought is,
| it's probably economic if you have access to intermittent
| sources of really cheap electricity.
| [deleted]
| lucioperca wrote:
| They might be just connected to the Euro-Powergrid in the
| future: https://www.landsvirkjun.com/researchdevelopment/subm
| arineca...
| svara wrote:
| Many of the things you're saying aren't correct, see my other
| comment (sibling to yours) for references.
|
| Nuclear is not cheap compared to photovoltaics, wind and hydro.
| Since the former two are bursty, overcapacity in them leads to
| cheap excess energy at times, which needs to be stored.
|
| Which storage method is the best depends on multiple factors,
| particularly on the duration of storage, capacity required and
| frequency of charging/discharging.
|
| Batteries are great for relatively short term storage, but for
| long term, seasonal storage, hydrogen and pumped hydro are the
| options we have. Pumped hydro capacity is limited, and the cost
| of hydrogen production and storage is coming down. So that's
| where hydrogen makes sense: Long term, high capacity storage.
| threatripper wrote:
| > Many of the things you're saying aren't correct, see my
| other comment (sibling to yours) for references.
|
| I really wish that I was wrong instead of just semi-accurate
| and sloppy.
|
| > Nuclear is not cheap compared to photovoltaics, wind and
| hydro.
|
| The price of nuclear power is dominated by regulation.
| Running the power plant is quite cheap. The real cost is
| satisfying regulation and getting rid of the nuclear waste.
| If you use new reactor designs it promises to be really
| cheap. But currently regulation cost is so high that it's not
| happening any time soon. Similarly, nuclear fusion promises a
| lot. Maybe one day it will deliver.
|
| My point is that IFF you have dirt cheap nuclear energy, it
| would be quite appealing to convert it to hydrogen (or
| Methane/Methanol) and to replace natural gas and oil with it.
| But since that is not happening, renewables will NOT deliver
| enough energy to replace gas and oil completely any time
| soon. We have a factor of 10-100 to scale up for that to
| happen.
|
| > Since the former two are bursty, overcapacity in them leads
| to cheap excess energy at times, which needs to be stored.
|
| Wind and solar currently rarely have overcapacity because in
| many nations mandated by regulations the other sources will
| have to go offline instead. The problem is that if you really
| manage to build up wind and hydro to satisfy electricity
| demand on average the Hydrogen generators will only utilize
| somewhat in the region of 10% of their design capacity in
| average. They need to be very cheap to run at a profit for
| that.
|
| Also, if electricity is really cheap, we have a lot of uses
| for it. For example heating is ideally done using clean
| electricity. This substitution frees up a lot oil and gas
| that you can use instead of Hydrogen.
|
| > Which storage method is the best depends on multiple
| factors, particularly on the duration of storage, capacity
| required and frequency of charging/discharging.
|
| > Batteries are great for relatively short term storage, but
| for long term, seasonal storage, hydrogen and pumped hydro
| are the options we have. Pumped hydro capacity is limited,
| and the cost of hydrogen production and storage is coming
| down. So that's where hydrogen makes sense: Long term, high
| capacity storage.
|
| True. But if you have enough production capacity, you don't
| really need storage. You only store it if it is cheaper than
| simply generating more power when you need it. Instead of
| generating Hydrogen and storing it you could use a natural
| gas peaker plant. You have natural gas and storage solutions
| already available and installed. Hydrogen has to be cheaper
| than natural gas.
|
| You have some nice academic references while I only have
| anecdata that may be partially outdated by now. In my past
| experience Hydrogen and fuel cells have failed to deliver
| time after time, year after year while Lithium batteries have
| really taken off.
|
| Look at that figure: https://ars.els-
| cdn.com/content/image/1-s2.0-S25424351183058...
|
| Currently, Hydrogen is off the charts because it is too
| expensive but it is projected to come down and dominate the
| upper end in 30 years while Lithium batteries dominate all
| the rest. Lithium batteries are here today and the focus is
| on batteries. Natrium and other battery technologies may be
| ready by then and drop prices a further factor of 10.
|
| I do not deny that some Hydrogen from electricity makes
| sense. Especially if you need Hydrogen for your chemical
| processes. Maybe even for storage of excess electricity (or
| just adding it to the natural gas instead of storing it). But
| I don't see Hydrogen for small vehicles anytime soon.
| klft wrote:
| Dirt cheap for whom? Chernobyl costs Belarus 20% of its
| annual budget according to https://eu.usatoday.com/story/ne
| ws/world/2016/04/17/belarus-...
| ljf wrote:
| Nuclear power is only dirt cheap if the government/society
| picks up all the externalised costs for the storage and
| recycling of waste.
|
| Can you tell me which nuclear stations cover all their own
| costs?
|
| As far as I am aware, all nuclear power stations in the
| world do not bear that cost - it is always picked up by the
| government.
|
| They often figure that the long term cost is worth it for
| energy stability - not because nuclear is cheap - but
| because it is more stable than relying on energy imports
| from another country.
| manfredo wrote:
| The cost of storing waste is miniscule. Because there's
| so little of it. The entirety of the US's nuclear waste
| from electricity generation occupies a volume the
| footprint of a football field and 10 meters high [1]. The
| government did build a waste storage facility, which was
| planned to have cost $150 million [2]. Which is tiny
| compared to the tens of billions that nuclear plants
| themselves actually cost.
|
| The notion that cost of storing nuclear waste would make
| nuclear power considerably more expensive is incorrect.
|
| 1. https://www.energy.gov/ne/articles/5-fast-facts-about-
| spent-...
|
| 2. https://en.m.wikipedia.org/wiki/Yucca_Mountain_nuclear
| _waste...
| roelschroeven wrote:
| > 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 disposal solution is
| determined by the federal government.
|
| But from Wikipedia's page on dry cask storage, linked
| from your second link:
|
| > In the 1990s, the NRC had to "take repeated actions to
| address defective welds on dry casks that led to cracks
| and quality assurance problems; helium had leaked into
| some casks, increasing temperatures and causing
| accelerated fuel corrosion".
|
| > 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 for 100 years, but cracking
| related to corrosion could occur in 30 years or less.
|
| In other words the "safe" temporary storage is not really
| safe.
|
| From your second link:
|
| > In September 2007, it was discovered that the Bow Ridge
| fault line ran underneath the facility, hundreds of feet
| east of where it was originally thought to be located,
| beneath a storage pad where spent radioactive fuel
| canisters would be cooled before being sealed in a maze
| of tunnels. The discovery required several structures to
| be moved several hundred feet further to the east, and
| drew criticism from Robert R. Loux, then head of the
| Nevada Agency for Nuclear Projects, who argues that Yucca
| administrators should have known about the fault line's
| location years prior, and called the movement of the
| structures "just-in-time engineering."[80][81] In June
| 2008, a major nuclear equipment supplier, Holtec
| International, criticized the Department of Energy's
| safety plan for handling containers of radioactive waste
| before they are buried at the proposed Yucca Mountain
| dump. The concern is that, in an earthquake, the
| unanchored casks of nuclear waste material awaiting
| burial at Yucca Mountain could be sent into a "chaotic
| melee of bouncing and rolling juggernauts".[82]
|
| How sure can we be there are no other fault lines waiting
| to be found? How sure can we be earthquakes won't cause
| problems in 100 years, or 500 or 5000 years? The Yucca
| Mountain repository is supposed to last 10000 years. How
| do we know it will?
|
| Storing nuclear waste is a huge unsolved problem. What's
| going to happen is that we're going to put it somewhere
| out of sight and let future generations deal with it. As
| other posters said: the nuclear industry externalizes all
| its difficulties to government, society and even future
| generations.
| manfredo wrote:
| > Then how come that not a single country has yet
| developed a method for storing their nuclear waste safely
| and permanently?
|
| They have. Finland has built a disposal site: https://en.
| m.wikipedia.org/wiki/Onkalo_spent_nuclear_fuel_re...
|
| The US built the Yucca Mountain, but then Congress
| blocked its usage. This was done due to political
| posturing not technical concerns. Burying it in an area
| with no groundwater is a foolproof method of disposal
| short of hyperbolic scenarios involving societal collapse
| followed by a future people digging in an area with no
| resources for an inexplicable reason. Yucca mountain is
| not in a geologically active area, so the concern about
| earthquakes is moot.
|
| > How sure can we be there are no other fault lines
| waiting to be found? How sure can we be earthquakes won't
| cause problems in 100 years, or 500 or 5000 years? The
| Yucca Mountain repository is supposed to last 10000
| years. How do we know it will?
|
| After 10,000 years the uranium is no more radioactive
| than it was when it was dug out of the ground. And when
| Yucca mountain is filled the entrances are blocked by
| meters of concrete - even if canisters are somehow get
| compromised the uranium still needs to magically get
| through several meters of rock and concrete to get out
| into the environment.
|
| It is a solved problem, but politicians have decided not
| to use the solution. In the US that is, Europe has it's
| dig in Finland continuing as planned.
| roelschroeven wrote:
| > They have. Finland has built a disposal site: https://e
| n.m.wikipedia.org/wiki/Onkalo_spent_nuclear_fuel_re....
|
| > In 2012, a research group at the Royal Institute of
| Technology in Stockholm, Sweden, published research that
| suggests that the copper capsules of KBS-3 are not as
| corrosion-proof as SKB and Posiva claim. The research
| group led by Peter Szakalos estimated that the copper
| capsules would last only about 1,000 years, instead of
| the 100,000 years claimed by the companies. According to
| the research results, corrosion in pure copper advances
| at about one micrometre a year, whereas KBS-3 depends on
| a rate of corrosion that is a thousand times slower.
| Independent research conducted in Finland has supported
| the results of Szakalos's group.
|
| I said "safely and permantently".
|
| > Yucca mountain is not in a geologically active area
|
| > Nevada ranks fourth in the nation for current seismic
| activity.[78] Earthquake databases (the Council of the
| National Seismic System Composite Catalogue and the
| Southern Great Basin Seismic Network) provide current and
| historical earthquake information. Analysis of the
| available data in 1996 indicates that, since 1976, there
| have been 621 seismic events of magnitude greater than
| 2.5 within a 50-mile (80 km) radius of Yucca
| Mountain.[78]
|
| > DOE has stated that seismic and tectonic effects on the
| natural systems at Yucca Mountain will not significantly
| affect repository performance. Yucca Mountain lies in a
| region of ongoing tectonic deformation, but the
| deformation rates are too slow to significantly affect
| the mountain during the 10,000-year regulatory compliance
| period.
|
| So there is tectonic deformation in the area, but
| everyone who has a stake in the projects believes it
| won't be a problem. To me that sounds like the believe
| that the Challenger's O-ring couldn't cause problems.
|
| > After 10,000 years the uranium is no more radioactive
| than it was when it was dug out of the ground.
|
| Which is why I only mentioned shorter timescales.
|
| > And when Yucca mountain is filled the entrances are
| blocked by meters of concrete - even if canisters are
| somehow get compromised the uranium still needs to
| magically get through several meters of rock and concrete
| to get out into the environment.
|
| > The volcanic tuff at Yucca Mountain is appreciably
| fractured and movement of water through an aquifer below
| the waste repository is primarily through fractures.[73]
| While the fractures are usually confined to individual
| layers of tuff, the faults extend from the planned
| storage area all the way to the water table 600 to 1,500
| ft (180 to 460 m) below the surface.[74] Future water
| transport from the surface to waste containers is likely
| to be dominated by fractures. There is evidence that
| surface water has been transported down through the 700
| ft (210 m) of overburden to the exploratory tunnel at
| Yucca Mountain in less than 50 years.[75][76] > The
| aquifer of Yucca Mountain drains to Amargosa Valley, home
| to over 1400 people and a number of endangered
| species.[2] > Some site opponents assert that, after the
| predicted containment failure of the waste containers,
| these cracks may provide a route for movement of
| radioactive waste that dissolves in the water flowing
| downward from the desert surface.[77] Officials state
| that the waste containers will be stored in such a way as
| to minimize or even nearly eliminate this possibility.
|
| We already know the waste containers degrade much faster
| than originally thought. There is a significant chance of
| contamination of the groundwater.
| VBprogrammer wrote:
| One way of thinking about it is that nuclear power is the
| only type of power we have at the moment where all of the
| negative externalities are baked into the process.
|
| I really want renewables to work but so far grid scale
| batteries just don't exist. The biggest lithium battery
| isn't even a blip, it's roughly equivalent to what the UK
| receives through French over production every 6 minutes.
| nicoburns wrote:
| Do we really need long-term storage? Wouldn't it be cheaper
| just to overprovision production?
| pfdietz wrote:
| It's best to do both.
|
| Go play with this web site and look at the optimal
| solutions (for producing constant power output) under
| various cost assumptions, using real weather data.
|
| https://model.energy/
|
| Generally, the best solutions involve some overbuilding,
| some storage, and some combination of solar and wind. For
| sunny places, solar + batteries (+ a little hydrogen); for
| windy places, wind + hydrogen (+ a little solar and
| batteries).
| manfredo wrote:
| Seasonal fluctuations in energy production are more extreme
| in far northern and southern latitudes. Which just so
| happens to be where the majority of energy consumption is
| located.
|
| The amount of energy storage required even to just handle
| the daily duck curve is staggering. To put this in
| perspective, the US consumed 11.5TWh of electricity daily.
| Global lithium ion battery production is 300GWh per year.
|
| Until some truly groundbreaking storage mechanism gets
| developed, renewables have difficulty providing more than
| 40-50% of energy demand.
| anoncake wrote:
| Nonsense. No one's going to use lithium ion batteries for
| this use case.
| pfdietz wrote:
| Right. It's one of the common anti-renewable canards that
| batteries would be used for more than diurnal smoothing.
| manfredo wrote:
| I think you missed the point: even for diurnal storage
| the scale required amounts to a decade's worth of
| _global_ battery production just to create capacity equal
| to 1 /4th of just the US's daily electricity usage.
| pfdietz wrote:
| This is a very lame argument. Manufacturing capacity
| isn't some fixed constant of nature, it's whatever makes
| sense given the market for the product. So if there's a
| large market, a large manufacturing capacity will be
| created.
|
| https://cleantechnica.com/files/2019/04/2019-Q1-Growth-
| in-Gl...
| manfredo wrote:
| Even if we assume that the production capacity will
| continuously increases at the predicted rate, think you
| missed the part where that was just the US's storage
| requirements. Global electricity consumption annually was
| 22.3 PWh in 2017, yielding 61TWh per day. And while
| battery production increases, so too does electricity
| demand. Even if we assume that battery production
| increases to 1TWh-2TWh per year by 2030 as per your link
| we're still taking about decades to achieve even 1/4th of
| the _current_ (not 2030) daily electricity consumption
| even if 100% of battery production was dedicated to grid
| storage. And that 's not possible because grid storage is
| going to be competing with electric vehicles and
| electronics. And again, by 2030 were going to be using
| more electricity than we are currently. The necessary
| capacity is increasing exponentially. Pointing out that
| battery production is predicted to increase doesn't alter
| the fact that the scale required is massive.
|
| And this all this is ignoring the fact that batteries
| lose half their capacity after 300-500 cycles. Even if
| we're generous and say 1000 cycles that's still just 3
| years for diurnal use (daily charge and discharge
| cycles).
| pfdietz wrote:
| I didn't miss that. Why do you think global manufacturing
| capacity will stop when it reaches what the US needs, and
| not expand to satisfy the global market? You think the
| manufactures are going to leave sales and profits on the
| table for no good reason?
|
| The growth in production is being controlled by the
| growth in the market. New factories can be added at very
| high rate if needed. You are treating the manufacturing
| capacity as some exogenous constraint rather than
| something that can be changed along with everything else.
| manfredo wrote:
| Then what's the alternative? Kinetic storage is
| geographically limited. Th Sabatier process has end to
| end efficiency of ~30% not to mention it needs an
| external source of carbon dioxide. The remaining
| proposals are at the experimental stage (thermal storage,
| hydrogen storage).
| pfdietz wrote:
| 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 alkaline
| electrolysis systems). This is more than adequate for
| hydrogen storage.
| sacred_numbers wrote:
| It's almost always cheaper to overbuild renewables than to
| use seasonal storage. Seasonal storage is used once a year,
| so if you can store a Kwh of energy for $1 it still
| increases the cost of the stored electricity by 4-5 cents
| per Kwh. Let's look at a 1 Kw average output. Assume that
| you have 6 Kw of solar, along with 18 Kwh of batteries.
| This will work fine 7-8 months out of the year, but will
| not be sufficient for winter, so you will need seasonal
| storage. About 2000 Kwh should be sufficient to make up for
| the deficit. Alternatively, how much solar would you need
| to avoid seasonal storage? About 10-12 Kw would probably
| work. That would mean an additional $3,200 to $4,800 in
| capital costs, assuming 80 cents per watt of solar. In
| order for seasonal storage to compete it would need to cost
| less than about $2 per KWh. For hydrogen this would equate
| to about $40 per kg. That's on the low end of estimates
| I've seen for underground hydrogen storage, and doesn't
| even take into account the cost of generating the hydrogen.
| It also doesn't take into account revenue generated from
| selling excess electricity in summer. Even if you sold
| excess electricity for only 1 cent per Kwh you could still
| offset about half the cost of the extra solar capacity.
|
| I think many people see excess capacity as a form of waste
| to be reduced, but it's like thinking that gigabit fiber is
| a waste because it's not used to it's full capacity. The
| value of oversupply is that it's always available when you
| need it. The fact that new industries can spawn from the
| super cheap rates for excess electricity or data is just a
| bonus.
| pfdietz wrote:
| > It's almost always cheaper to overbuild renewables than
| to use seasonal storage.
|
| I disagree, especially at high latitudes. Try that in the
| UK, for example, at https://model.energy/
| SmokeyHamster wrote:
| >You need to convert other forms of energy to hydrogen at a
| loss.
|
| When wouldn't it be at a loss? That's just physics. Hydrogen
| fuel cells aren't a source of energy in and of themselves,
| they're just a storage medium, like any other battery. And the
| act of filling them will never by 100% efficient because
| nothing is, so there will always be loss.
| FabHK wrote:
| Yes, any conversion incurs a loss. The point is that hydrogen
| introduces additional conversions, because it must first be
| produced, and then converted to something useful.
| polishdude20 wrote:
| Hydrogen fuel cells don't store the hydrogen. They convert
| the hydrogen into electricity. The losses come from a:
| converting electricity to hydrogen by electrolysis and b:
| converting that hydrogen back to electricity.
| superklondike wrote:
| Why would I want to drive to a fueling station when I can plug my
| ev in at home?
| spenrose wrote:
| A summary of the virtuous cycle created by cheap renewables and
| hydrogen electrolyzation:
|
| https://www.carboncommentary.com/blog/2020/6/17/renewables-p...
|
| Lots of comments on this thread that reveal folks are up to date
| with the state of hydrogen infrastructure c. 2017. It's changing
| really fast as billions of dollars are poured into R&D and pilot
| projects. For example, storage and transport:
|
| https://uk.reuters.com/article/uk-japan-hydrogen-chiyoda-cor...
|
| Siemens has pledged to make turbines that run on 100% hydrogen by
| 2030:
| https://new.siemens.com/global/en/company/stories/energy/hyd...
|
| Hydrogen trains: https://www.snam.it/en/Media/Press-
| releases/Agreement_Alstom...
|
| Hydrogen in steelmaking:
| https://www.spglobal.com/platts/en/market-insights/latest-ne...
|
| I could post 15 more. Our collective priors were well-grounded
| just a couple years ago, but it is time for a big update.
| cheesecracker wrote:
| "might" - so it won't, again.
| jakozaur wrote:
| Main points:
|
| 1. The only hydrogen produced from electricity is ecological.
| Carbon capture doesn't work today.
|
| 2. The hydrogen from electricity is expensive, though as wind and
| solar get exponential cheaper, we will end up with spikes excess
| cheap electricity (negative prices today or disconnecting
| plants). It makes sense to produce hydrogen during those spikes.
|
| 3. Cars on hydrogen don't make sense at all. The massive cost of
| infrastructure plus batteries are superior and getting better on
| that front.
|
| 4. Hydrogen from electricity can replace the first reformation
| from natural gas.
|
| 5. Next promising use cases are industrial heating, such as steel
| production (instead of coal).
|
| 6. Least profitable, but still plausible, uses hydrogen as long-
| term energy storage and mixing it with natural gas.
|
| 7. I wonder whether generating hydrogen from seawater and getting
| back freshwater would improve the economics of this form of
| energy storage.
| harg wrote:
| I don't know if you had access to the whole article but it
| addresses all of the points you mention (except 7).
| postingawayonhn wrote:
| > It makes sense to produce hydrogen during those spikes.
|
| I'm not sure that it necessarily does. If you're only producing
| during those peak periods of electrical output then your you're
| going to have a lot of hydrogen producing equipment sitting
| idle at other times.
| maxerickson wrote:
| 1 kg of (electrically produced) hydrogen costs more than 1000
| gallons of desal.
|
| (1 kg of hydrogen would make a few gallons of water)
| hwillis wrote:
| edit: misinterpreted "desal" as diesel rather than
| desalinated water.
|
| Well that's just not at all true. Hydrogen by electrolysis
| costs <$20/kg. A much more interesting fact about a kg of
| hydrogen is also that it has very close to the same energy
| content as a gallon of diesel, and significantly more when
| used in a fuel cell vs an ICE.
|
| https://www.nrel.gov/docs/fy04osti/36734.pdf
| maxerickson wrote:
| 1000 gallons of desalination costs $2 or $3.
|
| I was responding to point 7, not comparing hydrogen to
| _diesel_.
| hwillis wrote:
| ah, I thought you had misspelled.
| mitchtbaum wrote:
| pedal power also propels
| Majromax wrote:
| This article looks like a fine discussion about the economics of
| hydrogen production, but unless I've missed something it skips
| over the immense storage difficulty.
|
| Hydrogen is a difficult thing to manage in quantity. Its density
| is fantastically low, so storing it in gas form requires absurd
| pressures -- an inherent risk to any vehicle. Storing it in
| liquid form goes a long way towards solving the density/pressure
| problem, but now the system must have a full cryogenic process to
| _keep_ the hydrogen liquified. (Worse yet: over time hydrogen
| embrittles (https://en.wikipedia.org/wiki/Hydrogen_embrittlement)
| metals, making storage even more complicated)
|
| This isn't much different than the problems faced by rockets, and
| it's why liquid hydrogen is not considered a 'storable
| propellant' for long-duration flight.
|
| In a zero-net-carbon economy, residual demand for high power
| density may still have to be filled by some kind of bio-derived
| or synthetic hydrocarbon.
| dmix wrote:
| Now I'm curious how Hyundai or the stations actually produce
| the hydrogen fuel.
|
| Edit: this video had a good overview of the various production
| methods, including on-site at the fuel station
| https://www.youtube.com/watch?v=f7MzFfuNOtY
| darksaints wrote:
| We don't need to rely on metals for hydrogen
| storage...composites work just fine. And for use cases like
| maritime and aviation power systems, cryogenic storage _isn 't
| necessary_. At all. Because even with simple styrofoam
| insulation, consumption rates vastly exceed evaporation rates.
| mcot2 wrote:
| Not to mention the efficiency of converting the stored Hydrogen
| to power. It's hard to beat the efficiency of a battery and
| electric motor.
| superklondike wrote:
| EV owner here. Why would I want to drive to a fueling station
| when I can fuel up at home with electricity? And from a
| maintenance level, ev's have substantially fewer parts and almost
| zero maintenance, whereas hydrogen perpetuates the ICE-engine
| paradigm... frequent oil changes, many moving parts, lots of
| service costs at the dealership. The economics of H2 may be
| different at the commercial scale, but we use a Chevy Bolt in a
| far northern climate and get nearly 200 miles of range in the
| winter. The future is already here, and H2 missed the consumer
| vehicle bandwagon.
| jitendrac wrote:
| 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.
| threatripper wrote:
| Why not use electricity or natural gas for heating? Both would
| be more efficient than using hydrogen as an intermediate step.
| jitendrac wrote:
| For current circumstances this makes sense, Natural gas is
| not carbon neutral.
|
| For electricity, as the renewable energy generation capacity
| will increase, Storage of excess will be essentially
| required. when in near future we develop viable tech to
| generate hydrogen from electricity with low or no carbon
| impact at reasonable efficiency,we can save them in
| underground reserves(Safest way in my view) and use existing
| piping infrastructure of natural gas for its transportation.
| we need to do research and wait for appropriate tech to be
| available.
| [deleted]
| goda90 wrote:
| The article didn't touch on this at all, so has anyone heard
| updates on attempts at doing in-vehicle hydrogen production from
| water and some sort of reactant? It's been years since I saw
| something on it, but if I recall, it used some pellets made of
| certain metals that react with the water to produce hydrogen.
| You'd fill the tank with water, and after some number of fill ups
| you'd also need to replenish the pellets which could be sent off
| for recycling.
|
| Edit: I found an article about this. It appears to have been
| developed by the military and has been licensed out for more
| development: https://techxplore.com/news/2019-07-h2-power-
| hydrogen-fuel-s...
| threatripper wrote:
| In that case you'd be better of using methanol which can also
| be used in fuel cells.
| Erlich_Bachman wrote:
| A theory like that ignores most of known basic physics.
|
| What would the energy source be? It does not matter what
| chemical or electrochemical reactions are possible in general,
| what matters is where does the energy come from. Water does not
| contain any energy. (Not any chemical energy that can easily be
| extracted. Of course it contains energy in the sense that
| E=MC^2, but in that sense we have about the same chance to run
| a car on sand, or rocks or oreos.)
|
| On the other hand, if you do have an energy source, then why
| would you need water at all?? You would just use the energy to
| drive the car (like EVs do), you wouldn't waste half of it to
| hydrolysis of water into hydrogen first to use that hydrogen...
|
| A theory about a "car running on water" (which, at least in my
| experience is often followed by conversations about how Nicola
| Tesla could transfer energy through the air, or about how
| government has all the technology for infinite energy, but they
| block it from being used because they are evil) - is a pipe
| dream which is heavily based on ignorance about physics and
| gross underestimation of the difficulty of real engineering
| problems.
| goda90 wrote:
| I found the Wikipedia article: https://en.m.wikipedia.org/wik
| i/Aluminum_based_nanogalvanic_...
|
| Saying this ignores basic physics is like saying gasoline
| engines ignore basic physics. No one is saying that it's free
| energy. The question is, what is the energy to
| produce/recycle the alloy? How many miles can you get out of
| a reasonable supply of the alloy before replacing it? If
| those numbers are good enough, maybe they'll perform better
| than battery vehicles. And so I'm asking what's the state of
| that research.
| bambam24 wrote:
| Does people get referral bonus for sharing this paid website
| links?
| dang wrote:
| Paywalls are ok if there's a workaround. Users usually post
| workarounds in the thread. Yes, it sucks, but the alternatives
| suck worse. The Economist has been the source for a lot of good
| HN discussions, as have other soft-paywalled sites. We don't
| allow hard-paywalled ones.
|
| This is in the FAQ at https://news.ycombinator.com/newsfaq.html
| and there's more explanation here:
|
| https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...
|
| https://news.ycombinator.com/item?id=10178989
| gandalfian wrote:
| I think the charts are saying roughly a litre of lithium battery
| has 1kwh, a litre of liquid hydrogen 3kw and a litre of petrol
| 10kw. By 2050 your litre of green hydrogen might cost 10 cents to
| make or 3c per kWh.
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