27 ms·

Ditch the Batteries: Off-Grid Compressed Air Energy Storage

• penetrarthur 8y ago
  Volvo diesel cars avoid turbo lag by storing compressed air. Not very relevant but interesting nevertheless https://www.roadandtrack.com/new-cars/car-technology/news/a27515/volvos-diesel-turbo-lag-solution-is-compressed-air/ https://www.roadandtrack.com/new-cars/car-technology/news/a2...
  • imeron 8y ago
    And Bosch uses compressed air to keep motorcycles on track (experimental tech) https://www.youtube.com/watch?v=3ERowrZJyfw https://www.youtube.com/watch?v=3ERowrZJyfw
    • tonyedgecombe 8y ago
      If you could point them backwards for a little extra thrust ...
      • johnbrodie 8y ago
        Modern supersports are pushing ~200hp, no need for the extra weight that would generate the thrust.
        • stcredzero 8y ago
          The Spitfire actually used the jet propulsion of the rearward facing exhaust for an extra few horsepower. Many piston engine aircraft do this.
  • rusk 8y ago
    ABS braking does the opposite: a vacuum is stored that's used to release the brakes in short bursts.
    • dsfyu404ed 8y ago
      Modern (post 1990-something) ABS has its own pump. Air brakes on trucks run in reverse. Compressed air releases spring pressure therefore releasing the brake.
      • blattimwind 8y ago
        > Air brakes on trucks run in reverse. Compressed air releases spring pressure therefore releasing the brake. I think pneumatic brakes almost universally work this way, because it's fail-safe w.r.t. line leaks. E.g. in trains the main air line is for powering pneumatics as well as releasing brakes; at nominal pressure (8-10 bar iirc) the brakes are released, at lowered pressure (3-5 bar) the brakes are fully applied. If the line ruptures or the train splits all brakes across the train are fully applied.
• newman8r 8y ago
  An added benefit is you could power your air-tools with something like this without having to convert to electrical energy. As a former off-gridder, that's actually a really big plus. Another non conventional way to store energy is using gravity power modules (example: http://www.gravitypower.net/ http://www.gravitypower.net/) Storing hydrogen from electrolysis via solar panels also sounds interesting. Basically once your batteries are charged you start making hydrogen.
  • brittohalloran 8y ago
    Similar to those gravity power modules: a company called Ares (https://www.aresnorthamerica.com/ https://www.aresnorthamerica.com/) is trying to use much smaller concrete 'cars' on rails to store energy. Not sure of the status of it but it looked promising to me. The direct use of compressed air is interesting. Taking it to the extreme, you could have compressed air as your primary utility piped through your home, and have appliances that run off compressed air. Refrigeration cycle is compression based anyway for example. You would still need some electricity for control circuits for example, but you might be able to keep the heavy lifting air-based.
    • VikingCoder 8y ago
      Nah, there's water-based computers, there could be compressed air computers. Picturing the different logic gates running on compressed air is a hoot.
      • mikeash 8y ago
        You should check out Ted Chiang’s story “Exhalation.”
        • VikingCoder 8y ago
          This seems to be a legal copy of it? http://www.nightshadebooks.com/Downloads/Exhalation%20-%20Ted%20Chiang.html http://www.nightshadebooks.com/Downloads/Exhalation%20-%20Te...
• tomhoward 8y ago
  Reminds me of this project from a few years ago: a two-person hot-rod driven at up to 20mph by a 256-cylinder compressed-air engine, constructed out of Lego... https://www.youtube.com/watch?v=_ObE4_nMCjE https://www.youtube.com/watch?v=_ObE4_nMCjE
• jakecrouch 8y ago
  Lightsail Energy tried and failed to bring this to market - not sure whether this can ultimately outperform Lithium Ion Batteries, which have all the pressure of the electronics industry behind them.
  • newman8r 8y ago
    I feel like they have different applications so they're not necessarily competing. Obviously compressed air systems will never have the energy density of a battery, but they could be much more reliable. It also scales up really easily, and I think that's where the sweet spot is - I've heard of people sealing off caves to make giant air storage tanks for these projects.
    • oori 8y ago
      "sealing off caves" - would love to see, or hear the facts. Specifically, about safety of the pressure "chamber".
      • newman8r 8y ago
        https://caes.pnnl.gov/ https://caes.pnnl.gov/ - it's an interesting project. Apparently it's more like 'underground caverns' than caves.
      • jandrese 8y ago
        I think it is more typically done with old mines. Natural caves are far more complex systems and there are environmental concerns.
        • newman8r 8y ago
          you're right - it looks like the caverns being used for experimentation are the result of solution mining for salt.
  • telchar 8y ago
    The charge/discharge efficiency for compressed air is terrible since most of the energy gets wasted as heat. This plus the terrible volumetric energy storage density makes it a nonstarter for most applications.
• rossdavidh 8y ago
  So, I seem to recall that the Amish sometimes use something like this to power their tools. Source: my own unreliable memory of an article I read somewhere. Anybody more knowledgeable out there able to confirm or disfirm?
  • manveru 8y ago
    There's an article about it at http://www.amishnews.com/amisharticles/amish_tech.htm http://www.amishnews.com/amisharticles/amish_tech.htm which references some books that might describe it in more detail. > Almost any electrical appliance can be adapted to work off of alternate power, such as compressed air. Some Amish women have been using compressed air to power blenders in the kitchen for years. In one house, compressed air powers a water pump, sewing and washing machines, and drills and saws in the shop. Some Amish businesses have as their specialty adapting such appliances so they can be powered by compressed air.
  • nickynickell 8y ago
    Not a hard confirm, but I stood there marveling at the pneumatic ceiling fans in an Amish bakery once. Each one had a little oscillating engine and some plumbing for the compressed air.
  • pjmorris 8y ago
    Maybe the article was 'Amish Hackers' by Kevin Kelly? [0] http://kk.org/thetechnium/amish-hackers-a/ http://kk.org/thetechnium/amish-hackers-a/
  • nightbrawler 8y ago
    While I was researching offgrid options a few years back I came across this site and their windmill for compressed air: https://www.cottagecraftworks.com/wind-compressor-wind-driven-air-compressor-alt-energy https://www.cottagecraftworks.com/wind-compressor-wind-drive... They also have quite a few interesting compressed air kitchen appliances...such as mixers, grain mills.
• corey_moncure 8y ago
  An early design for the automobile ran on compressed (liquid!) air. http://www.didik.com/ev_hist.htm http://www.didik.com/ev_hist.htm It might work for some applications, but in 120 years we haven't been able to make it work for cars, at least.
  • JustSomeNobody 8y ago
    > ... but in 120 years we haven't been able to make it work for cars... Ok, but has anyone worked on the problem in the past 120 years?
    • brohee 8y ago
      https://www.mdi.lu https://www.mdi.lu tried to make compressed air two person urban cars (Air Pod) but with the main inventor and visionary now dead I don't know if there is much momentum left...
  • tomatotomato37 8y ago
    I suggest anyone interested in the history of compressed air storage to also check out http://www.douglas-self.com/MUSEUM/LOCOLOCO/airloco/airloco.htm http://www.douglas-self.com/MUSEUM/LOCOLOCO/airloco/airloco.... There's also a few articles on the website about compressed air cars and city-wide infrastructure
  • jandrese 8y ago
    IIRC there are compressed air cars used in India. They aren't very good, but you get free air conditioning when they're moving and they're cheap, so they fit the market well.
  • blattimwind 8y ago
    Has worked fine for compressed-air locomotives in e.g. mines.
• Uhrheber 8y ago
  When compressing air, a lot of heat is generated, and in most cases wasted. When the air is released, it cools down, and has to take heat from the surroundings. Which doesn't work very fast without additional heat exchangers, and especially not in cold environments. Compressed air storage is only efficient with additional heat storage, which is something that promoters of compressed air storage often "forget" to tell you.
  • larrik 8y ago
    Did you read the article? All of that is in like the first paragraph.
    • qop 8y ago
      What the parent said was still useful I think to people who might not know this particular trope throughout the industry.
  • josefresco 8y ago
    They didn't forget - it's addressed in detail. They are advocating "small scale" The low efficiency is mainly since air heats up during compression. This waste heat, which holds a large share of the energy input, is dumped into the atmosphere. A related problem is that air cools down when it is decompressed, lowering electricity production and possibly freezing the water vapour in the air. To avoid this, large-scale CAES plants heat the air prior to expansion using natural gas fuel, which further deteriorates the system efficiency and makes renewable energy storage dependent on fossil fuels.
    • davidhyde 8y ago
      Going "small scale" does not solve the heat problem unfortunately. If it does then the authors did not mention it. All they mentioned is how large scale plants deal with the problem.
      • josefresco 8y ago
• drizzle87 8y ago
  I was quite excited by compressed air storage when Lightsail came into the picture almost 5-7 years ago. Sadly, they could not make the economics work and ended up pivoting into a company that sells carbon fibre tanks for high-pressure storage. As someone who follows the energy space closely, Lithium ion batteries now have so much momentum and $$$ pumped into them via R&D work, it's going to be hard for competing energy storage technologies to catch up. Flywheel and hydrogen fuel-cell also often come up but I think we're at a point now where batteries are going to take off simply because of their wide area of applicability. With that economy of scale costs will drive down and even more research and $$$ will flow.
  • at-fates-hands 8y ago
    My concern with batteries is we're so gung ho on producing these, we haven't stopped to consider the environmental impact from the manufacturing process or the incredible task of recycling these once they've outlived their usefulness. It reminds me a lot of when people pushed plastic for everything in order to save the trees and reduce paper consumption. Some 40 years later, we're now trying to get off plastic and dealing with massive environmental issues surrounding nearly every kind of plastic.
    • batbomb 8y ago
      Do you think it’s better or worse than the initial mining?
    • lr 8y ago
      This guy actually goes to a lithium "mine" in the middle of the desert... https://www.youtube.com/watch?v=0KX2qw79qpk https://www.youtube.com/watch?v=0KX2qw79qpk
    • linsomniac 8y ago
      Back in the late 1800s, city planners met to try to come up with some plan for dealing with "the manure problem". Large cities couldn't handle the amount of manure produced by the horses in the city. They ended the meeting early, because they couldn't come up with any sort of plan. Then cars came along and they were all like "Yay! The pollution problem is solved!" I too wonder what the impact of so many lithium batteries is going to be. I mean, I know they are saying that they are extremely recyclable, and I hope that's true. But I wonder what the unintended consequences of this switch is going to be.
• donquichotte 8y ago
  At ETH Zurich, there is a project aiming at scaling compressed air storage to MWhs. [1] The interesting part is that they are trying to make the storage adiabatic, i.e., they store the heat that is generated while compressing the air in a phase change material (i.e., a material that will become liquid when hot, since a lot of energy can be stored in phase transitions) and get the heat back to warm up the cold expanding gas on decompression. The issue is that even with the phase change storage, heat will dissipate into the rock within a couple of days, making the whole process inefficient for long-term storage. [1] https://www.ethz.ch/content/specialinterest/mavt/energy-technology/renewable-energy-carriers/en/research/energy-storage/elecstor.html https://www.ethz.ch/content/specialinterest/mavt/energy-tech...
  • jononor 8y ago
    Sounds like a promosing solution for averaging out daily fluctuations though.
• mabbo 8y ago
  > However, to store 360 Wh of potential electrical energy, the system requires a storage reservoir of 18 m3, the size of a small room measuring 3x3x2 metres. The authors note that “although the tank size appears very large, it still makes sense for applications in rural areas”. This would light a home for an hour, with LED bulbs and careful usage. And all it requires is a room-sized storage tank. So if I wanted something that ran my house all night, I'd need a storage tank larger than said house.
  • hedora 8y ago
    I thought this too, but read the rest of the article. Spoiler alert: State of the art is 30x better
    • deleted 8y ago
      [deleted]
    • test6554 8y ago
      I picture Rick Moranis operating a large space-based vacuum cleaner.
  • sandworm101 8y ago
    Or you could liquify the air. That would make the storage much more energy-dense but introduces all sorts of practical/heat issues. People have played around with running cars on liquified nitrogen. The air conditioners probably worked well.
    • bdamm 8y ago
      Steam power, in a sense. Now I kind of want to build one, although the crash scenario is just as terrifying as with a hot car. Hmm.
      • reaperducer 8y ago
        There are clubs and people all over the United States (often in rural areas) dedicated to building home-made steam powered machines and vehicles. Unfortunately, these real-life steampunks (not cosplay kids) usually also would rather spend time working on their projects and not documenting them, so there's not very much on the internet compared with the number of people active in the hobby. Keep an eye out at county fairs and small town carnivals and rodeos. They usually show up.
• JohnJamesRambo 8y ago
  I'm surprised no one is talking about how scary it is that you are basically making a high powered bomb at your house any time you have one of these. Anyone that has watched Mystbusters understands the incredible destructive power stored in compressed air. I'll stick with batteries, thanks.
  • beat 8y ago
    You probably keep multiple gallons of gasoline nearby, tho.
    • evan_ 8y ago
      Not to mention the giant propane tanks that many houses in rural areas already have
      • JoeAltmaier 8y ago
        Not the same? Shoot a propane tank, it leaks. No oxygen in the tank. There is very little outside compressed gas that can explode disastrously without oxygen. A tank of compressed gas is probably high up on the 'bomb in the house' category. Just under the water heater I suppose.
      • IkmoIkmo 8y ago
        Or the LPG tanks hundreds of millions of people have in their homes outside the developed world. e.g. India, Brazil, much of North Africa etc. They're considered quite safe, though.
    • JohnJamesRambo 8y ago
      Gasoline has to be mixed in a perfect ratio with air to be dangerous and explode. A simple leak from that enormous amount of air storage could be catastrophic. A leak of your gas tank and it just piddles out on the ground.
    • bdamm 8y ago
      Air is far more explosive than gasoline. Gasoline is practically docile compared to the equivalent energy stored as compressed air. When a vessel of compressed air ruptures, it almost instantaneously decimates everything around it with a powerful shockwave. Think of a popping balloon, but scaled up 10000x. You think a hot water heater is bad? Just imagine the entire house being demolished in a second. Gasoline, on the other hands, just burns in a hot concentrated fire. It takes entire minutes to kill that which is nearby.
• leowoo91 8y ago
  Afaik, compressed air energy startups come and go since long time, this should be ok for use in enterprise though.
• driverdan 8y ago
  It's interesting to see research done in this space but it's not even remotely practical yet. Their 410Wh system is more complex, five times larger, and has a much higher up front cost than an equivalent amount of lithium battery storage.
• toolslive 8y ago
  Hold on... So if you take a Tesla, remove the batteries, remove the electro engine, and replace that with a trivial compressed air based pneumatic motor it would be more eco friendly, more powerful and have a higher autonomy ?
  • danieltrembath 8y ago
    Unfortunately there are downsides, but compressed air vehicles are already a thing. https://en.wikipedia.org/wiki/Compressed-air_vehicle https://en.wikipedia.org/wiki/Compressed-air_vehicle https://en.wikipedia.org/wiki/Compressed_air_car https://en.wikipedia.org/wiki/Compressed_air_car
  • balfirevic 8y ago
    From https://en.wikipedia.org/wiki/Compressed_air_car#Disadvantages https://en.wikipedia.org/wiki/Compressed_air_car#Disadvantag... - A 2005 study demonstrated that cars running on lithium-ion batteries out-perform both compressed air and fuel cell vehicles more than threefold at the same speeds. - A 2009 University of Berkeley Research Letter found that "Even under highly optimistic assumptions the compressed-air car is significantly less efficient than a battery electric vehicle and produces more greenhouse gas emissions than a conventional gas-powered car with a coal intensive power mix."
• 1024core 8y ago
  Isn't there a loss in efficiency due to heat? Compressing air heats it up, which is lost (this is the basic principle behind refrigeration, though it doesn't use air). And then there's the loss in converting this PE back into electricity. Are these losses less than what's lost in LiON cells?
  • contravariant 8y ago
    Read the article they go into this in detail.
• g8oz 8y ago
  Also interesting is hydraulic energy storage. Any entrepreneurs want to take a shot with this system? http://license.umn.edu/technologies/z07054_hydraulic-energy-storage-systems http://license.umn.edu/technologies/z07054_hydraulic-energy-...
  • leblancfg 8y ago
    >Hydraulic energy storage systems store energy by compressing air similar to a battery storing energy in an electric circuit. Wait, did you read the article? :)
    • g8oz 8y ago
      Hydraulic systems and compressed air systems are usually regarded as separate things. Maybe the distinction is a bit arbitrary and the former can be regarded as a subset of the latter but there you go. edit: Google says hydraulic transmits power through fluid, compressed air through air/gas.
      • blattimwind 8y ago
        Pneumatic vs hydraulic is about compressible vs incompressible fluids. (Naturally, hydraulic oil is also a much better lubricator and an exceedingly superior sealant than oiled air).
• dpcx 8y ago
  Joey Hess has been using his fridge for off-grid energy storage... With lots of data around what he's seeing. It's really interesting, and he still gets to keep his food cold. EDIT: Not really used as a battery, but probably could be. http://joeyh.name/blog/entry/fridge_0.1/ http://joeyh.name/blog/entry/fridge_0.1/
• fleetside72 8y ago
  I worked for a company that had old underground mines and a power company used them to fill with compressed air when energy was cheap and then release and generate electricity when it is more expensive. My company got a cut.
  • preordained 8y ago
    Clever
  • reaperducer 8y ago
    I used to have friends in the oil industry in the 90's, and I remember them talking about the industry maybe using dried up wells the same way. I don't know if it ever became anything, though. As much as people consider the oil industry a bunch of evildoers, it is always at the forefront of the absolute latest in tech. Hard problems + money does that.
• natch 8y ago
  Or, don’t ditch the batteries. They work fine. The title of the article strikes me as one of those marketing titles possibly planted by a press release. Position the competing product as if it’s somehow bad. “Protein-free!” I’m not buying it.
• KirinDave 8y ago
  > The low efficiency is mainly since air heats up during compression. This waste heat, which holds a large share of the energy input, is dumped into the atmosphere. Wait... wait... I'm... not sure I believe the extend of this statement. If this isn't wrong it's certainly awkwardly worded.
• simonebrunozzi 8y ago
  > "they do not require rare or toxic materials" This benefit alone would make me hope for compressed air energy batteries to receive tons of funding, and become cost-competitive with other forms of batteries. Also, consider that there are three important elements in a battery "economics": 1) Weight / energy density - how much energy can you store, per weight of the battery? Important for cars. 2) Volume / energy density - how much energy can you store, per volume of the battery? Important for cars as well. 3) Cost / energy stored - how much does it cost to store a unit of energy? This can also be divided into two elements: setup (e.g. the cost of producing the battery and deploying it) vs maintenance (how much does it cost to keep the battery alive, over the years?) There are also other minor factors, such as reaction to environmental changes (e.g. temperatures, etc).
• andyidsinga 8y ago
  Its really interesting that they can get up to the efficiency of led acid batteries in applications for rural areas. I wonder if maintaining that large air tank is more difficult / costly than maintaining the batteries. Its also interesting that we're only talking about 116 PSI - I'm guessing CFM is more important. > A simulation for a stand-alone CAES aimed at unpowered rural areas, and which is connected to a solar PV system and used for lighting only, operates at a relatively low air pressure of 8 bar and obtains a round-trip efficiency of 60% -- comparable to the efficiency of lead-acid batteries. [7] However, to store 360 Wh of potential electrical energy, the system requires a storage reservoir of 18 m3, the size of a small room measuring 3x3x2 metres. The authors note that “although the tank size appears very large, it still makes sense for applications in rural areas”.
• newnewpdro 8y ago
  I always wanted to have an air compressor running every day on my otherwise quiet property.
• stmw 8y ago
  When compressed air energy storage comes up, it is always worth remembering PV = nRT, the ideal gas law. And then remembering that things are not ideal.
  • btrettel 8y ago
    Mechanical engineer here. The ideal gas approximation is plenty reasonable for the pressures and temperatures of interest here. https://en.wikipedia.org/wiki/Compressibility_factor https://en.wikipedia.org/wiki/Compressibility_factor
• trumped 8y ago
  I'd love to go nuclear ... charge your phone once a year?
• kazinator 8y ago
  How about steel springs? Rubber bands? Weights hoisted on cables?
• dylanz 8y ago
  I'm not knowledgeable about any of this, but how does this compare to a Trompe? https://en.wikipedia.org/wiki/Trompe https://en.wikipedia.org/wiki/Trompe
• gleglegle 8y ago
  Highview claims to be able to do this at prices competitive with Lithium batteries. https://www.highviewpower.com/technology/ https://www.highviewpower.com/technology/
• jeena 8y ago
  This reminds me of perri air from spaceballs https://4.bp.blogspot.com/-prQEijRsbNk/Vnq-6GVfO-I/AAAAAAAABjA/GSEn_ij3AzE/s1600/spaceballs-scrocco-perri-air.png https://4.bp.blogspot.com/-prQEijRsbNk/Vnq-6GVfO-I/AAAAAAAAB...
• sangnoir 8y ago
  Off-topic: one of my favourite Ted Chiang short stories - Exhalation[1] - is about compressed-air-based lifeforms. 1. http://www.lightspeedmagazine.com/fiction/exhalation/ http://www.lightspeedmagazine.com/fiction/exhalation/
• theyinwhy 8y ago
  Peugeot is working on this for years but it got frozen last year: https://www.groupe-psa.com/en/newsroom/automotive-innovation/hybrid-air/ https://www.groupe-psa.com/en/newsroom/automotive-innovation...
• tomohawk 8y ago
  Also works for vehicles. Hydraulic hybrids capture 3x more of the braking energy. https://en.wikipedia.org/wiki/Hydraulic_hybrid_vehicle https://en.wikipedia.org/wiki/Hydraulic_hybrid_vehicle There's a retrofit for garbage trucks that pays for itself in 2 years, or you can buy them new. http://www.govtech.com/transportation/Hybrid-Garbage-Miami-Dade-040511.html http://www.govtech.com/transportation/Hybrid-Garbage-Miami-D...
• awful 8y ago
  I would just love a couple of small vertical turbines slowly pumping up my underground storage. I live in a sometimes violent wind location, often just when I could use the energy to run the furnace. I could see easily augering 10-15ft holes , dropping in vertically buried, used, composite tanks bought off Ebay, run at a fraction of their max pressure. Easily adding more to increase capacity, as needed. Yes a little pock-pock noise of the pistons and check valves, but it would only happen when wind blows. Though, a tank failure may mean retrieving it off the roof.
• sgt101 8y ago
  Silly question - could tires be used to do this? I mean, could one improvise a storage system via a stack of car tires?
• ChuckMcM 8y ago
  I have argued unsuccessfully in the past that this technique would be an excellent data center strategy. That is especially true if you had your data center near the Columbia river and its near constant winds. Using wind power to compress into high pressure tanks, then when you need extra energy you pull it out and pipe the air expansion pipes through heat exchanges in the data center. That way heat from the data center goes to warming up the air (better efficiency when you feed it to the turbines) and it cools the data center which is part of what one might use the energy for in the first place. If you put the air expansion pipes in a conveniently located source of water you could chill that water to freezing.
  • cwkoss 8y ago
    If the entire contents of the data center were pressurized, would it increase the efficiency of air cooling? (Denser air -> more heat capacity?)
    • ChuckMcM 8y ago
      It would certainly increase the heat capacity of the air. Compressing air into the data center however would not be a win. During compression the air gets hot. In the system that I was pushing the compressed air tanks were outside in the wind so that they were benefiting from the cooling effects of the same wind that was pumping air into them.
      • cwkoss 8y ago
        Good point. Could allow for low power cooling (once pressurized, venting pressure would drop temperature of the contents without added energy), but probably not worth the trouble.
• Timothycquinn 8y ago
  Seems like a technology that has narrow usecases like where cogeneration is possible. I guess large city's and industrial applications which can use the waste products of the thermal cycle. For alternatives, my money in the long run is on molten salt batteries [1] for large scale. Technology also has benefit of increased industry knowledge of how to utilize molten salts safely which will benefit LFTR research. (1) http://news.mit.edu/2018/metal-mesh-membrane-rechargeable-batteries-renewable-energy-0122 http://news.mit.edu/2018/metal-mesh-membrane-rechargeable-ba...
• jacknews 8y ago
  This makes some sense in poor tropical nations, where rigging a mechanical system like this is quite feasible locally (instead of having to import advanced lithium batteries, along with usually exorbitant import duties etc), and some of the "inefficiency" can be used to heat, and particularly, cool spaces. It also makes sense for oceanic wind turbines, which can use periods of high wind vs low demand to pump air into large under-sea air storage bags, using the sea as free cooling/heating towards isothermal operation.