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For comparison, global jet fuel consumption for major airlines in 2013 was over 60 billion liters. (http://www.transtats.bts.gov/fuel.asp http://www.transtats.b

• yxhuvud 12y ago
  I wonder what the energy consumption would be though.
  • dkokelley 12y ago
    How do you mean?
    • rozap 12y ago
      I think he means that a lot of experimental energy sources require more energy than they produce, so it's a net loss.
      • bdamm 12y ago
        This problem is worth dedicating a few nuke plants to the problem, if in fact all you need is 1500 or 2200 deg C. Especially in Nevada, which has plenty of radioactive surface already.
      • dkokelley 12y ago
        Isn't the point that this process can be completed with the components in the air and the energy from the sun? At ~15% efficiency we're losing 85% of the potential energy from the sun, although we were previously capturing 0% of it. It should take an insignificant amount of input energy to begin the process, and then be a net energy positive for us.
        • bradleysmith 12y ago
          manufacture and assembly of components, and life-time & maintenance of parts should provide a 'break-even' formula for energy in vs. energy out. As long as building the machine doesn't cost more energy than it produces over X time period, you're right, the only inputs are sun and air, of which we have an practically unlimited supply. Happy to be corrected, just commenting for the sake of discussion. This is how I understand the 'efficiency' of such experimental energy to be determined.
          • breischl 12y ago
            It would also take up a massive amount of land and cover it with solar mirrors, likely causing local ecological damage. And you need roads & infrastructure to support construction and maintenance, and to move the product out. And houses for the workers, and places for them to shop, and and and....
          • zephjc 12y ago
            You still have to build and maintain power plants for extracting energy from other sources (coal, hydro, etc), which have huge additional costs.
• backprojection 12y ago
  That doesn't sound so bad. I wonder if the process could be made to work with salt water.
  • bradleysmith 12y ago
    A cursory glance says it's a very different process, but this is probably relevant: http://science.dodlive.mil/2014/04/11/energy-independence-creating-fuel-from-sea-water/ http://science.dodlive.mil/2014/04/11/energy-independence-cr...
• gmarceau 12y ago
  Jet fuel sells for $2.88 per gallon (76 cents per liter), http://www.indexmundi.com/commodities/?commodity=jet-fuel http://www.indexmundi.com/commodities/?commodity=jet-fuel If the entire world worth of jet fuel was obtained from Nevada, it would inject around 4 billion dollar per year into Nevada's economy, or around $1500 per capita every year. I can imagine them choosing the money over the land.
  • knowaveragejoe 12y ago
    It may not be the State's choice, though. Something like 85% of Nevada is Federal land.
  • dkokelley 12y ago
    That might only be an upper limit on the economic potential. After all, buyers need to be incentivized to switch suppliers, and the fuel needs to be transported to where it is needed. I used Nevada as an example because it's a low population density, highly undeveloped, sunlight-rich state, which makes it ideal for solar production plants. I'm sure other production facilities will spring up in the California desert and similarly situated regions around the world. What excites me most about solar energy plants is that it's ideal for our empty desert regions - Lots of sunlight, lots of undeveloped land, low population. Edit: The $4 billion figure seems off. If global demand is 60 billion liters, that's $45.6 billion at $0.76/liter. Am I missing something?
  • kashkhan 12y ago
    that's not really how it will work. If to generate $1500 per year each person needs to invest $150,000, then it ain't gonna happen.
  • theorique 12y ago
    I'm finding a daily consumption of 200M gallons, or 73B gallons annually. This would work out to a global consumption of about $220B worth of jet fuel, not $4B.
    • dkokelley 12y ago
• kokey 12y ago
  This could also be a nice alternative way to create a liquid fuel from nuclear energy.
  • ChuckMcM 12y ago
    That is the interesting thing, you could build a nuclear plant which in the center of a circle, the circle with an area the size of 3% of Nevada) and use it to make kerosene all day and all night. But we likely won't do that. However the first fusion plants, will probably dump excess production in the form of dense hydrocarbons for all the reasons listed here (lowers CO2 footprint, saves production energy for 'later', can be easily transported.)
  • Dn_Ab 12y ago
    It's much more economical to extract from the ocean, higher concentrations and working from largest sink mitigates a lot of envirodamage of CO2: http://www.dtic.mil/cgi-bin/GetTRDoc?doc=GetTRDoc.pdf&AD=ADA539765 http://www.dtic.mil/cgi-bin/GetTRDoc?doc=GetTRDoc.pdf&AD=ADA..., http://en.wikipedia.org/wiki/Carbon-neutral_fuel#Renewable_and_nuclear_energy_costs http://en.wikipedia.org/wiki/Carbon-neutral_fuel#Renewable_a...
  • leoc 12y ago
    Relevant: http://www.nrl.navy.mil/media/news-releases/2014/scale-model-wwii-craft-takes-flight-with-fuel-from-the-sea-concept http://www.nrl.navy.mil/media/news-releases/2014/scale-model... http://www.washingtontimes.com/news/2014/apr/10/game-changer-us-navy-can-now-turn-seawater-jet-fue/ http://www.washingtontimes.com/news/2014/apr/10/game-changer... . You can see why the technology would appeal to the US Navy, even if it's not quite price-competitive with other means of getting jet fuel: they're keen to untether their carrier groups from the supply chain as much as possible, which is partly why they have the convenient nuclear reactors already.
    • dredmorbius 12y ago
      My read is that the "supply chains" arguments are largely incorrect. The scale of operations of the 100kgal/day site would vastly exceed the available onboard space available within any existing warship -- you'd need a floating platform of some sort dedicated to the task. Since the proposal presumes use of a carrier's own nuclear plant to supply power for the operation, the carrier would be physically tethered to the fuel synthesis platform. Carrier operations require operating at near flank (top) speed for takeoffs and landings. You couldn't fight and fuel at the same time. Even task-switching between modes would be at best cumbersome. The US NRL's own research materials propose a fixed-site pilot, perhaps powered by OTEC (ocean thermal energy conversion) as a renewable energy source (this provides constant 24/7 power based on sea temperature gradients from sites such as the Hawaiian Islands with proximate shallow and deep-water zones at large temperature differential). Similarly any electrical power source, most conceivably renewable solar or wind, or nuclear, could be used for fuel synthesis. My back-of-the-envelope calculations suggest that supplying the equivalent of present-day US petroleum consumption would be plausible. It would require a few thousand km^2 of solar capacity, a roughly 10m tall by 4.5m square processing plant, and capital of roughly $8 trillion (based on USNRL's estimates) for synthesis and likely 1-2x that for the solar capacity. In either case, you'd still have tankers and tenders transporting fuel, what you'd eliminate is the specific reliance on routes from existing petroleum extraction and refining sites. Overall efficiency should be vastly better than the levels discussed here. Limiting point seems to be hydrogen electrolysis, which is 60% efficient (in terms of hydrogen energy potential) based on existing operational data. The Fischer-Tropsch reaction is pretty low in energy demand, or net positive. There are _vast_ volumes of seawater which would have to be processed, and pumping of that could be a significant energy cost (or perhaps tidal flows and some clever one-way-flow solid-state valves could be used to accomplish this: http://makezine.com/2012/01/05/the-tesla-valve-one-way-flow-with-no-moving-parts/ http://makezine.com/2012/01/05/the-tesla-valve-one-way-flow-...). It's not clear to me what the actual efficiency of the USNRL's method would be, though it seems clear that 60% net energy recovery is a theoretical maximum. I'd suspect 20-50% might be reasonably attained -- and that's far, far higher than the 1.7% claimed by the article referenced by this HN post.
• Gravityloss 12y ago
  Jets are not the first or even the tenth problem. We are burning coal for electricity as we speak.
  • pcl 12y ago
    I believe that these synthesis problems are targeting jet fuel because it's easier to manufacture than other forms of fuel, due to the simple chemical structure of kerosine.
    • XorNot 12y ago
      It's also because oil availability is kind of a very important problem for the world's militaries.
  • dredmorbius 12y ago
    Synthetic (or biofuel) for aviation is of interest because, very simply, existing commercial aviation cannot exist without cheap and abundant liquid hydrocarbon fuels. Already rising fuel costs have vastly affected the industry. US "peak aviation fuel" occurred in 1999. Peak departures was in 2005. 2012 consumption is _half_ of what was forecast in 2000, and departures 30% of the trend as of 2005 (even allowing for recession). I first ran into this fact in January while looking into a biofuel "breakthrough" touted by Boeing (breakthrough or not it's wholly inadequate for needs): http://redd.it/1wo2hl http://redd.it/1wo2hl The departures data comes from a presentation by Steven Kopits made in February which I didn't come across until April: http://energypolicy.columbia.edu/events-calendar/global-oil-market-forecasting-main-approaches-key-drivers http://energypolicy.columbia.edu/events-calendar/global-oil-... While passenger miles are still up, net, from 2000 levels, that's only on account of more efficient aircraft and higher load factors (that reduced legroom isn't just in your head). So that's the problem scope. Electricity is largely a solved problem: we can generate it with solar, wind, geothermal, hydro. Even nuclear for some bridging potential (though fuel availability even for thorium is decidedly limited as I calculate it http://redd.it/23nvqs http://redd.it/23nvqs). Other than air travel, most transport needs are also tractable. Personal transport can be addressed via denser development, bicycles, electrified mass transit, personal electric vehicles, and other means. Rail can be electrified. Drayage (non-rail overland transport) is trickier, but might be addressed through EVs, biofuels, and even animal locomotion in a pinch. Ocean shipping might return to use of sail or solid biofuel in the form of pelletized fuels. But you cannot fly planes which carry appreciable cargos of people or freight useful distances reliably at speed without liquid fuels. So addressing that is of interest (an alternative would be to forgo flight or switch to lighter-than-air craft). Personally I find the prospect of seawater-based fuel synthesis far more likely than air-based technologies: much richer carbon source, and likely far higher efficiencies.