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You seem to have read only the introductory paragraphs. There is little need to store or transport hydrogen that may be produced right where and when it is nee

• wongarsu 4y ago
  If I read the abstract correct it's doing electrolysis of moisture in the air. That's a process that inherently uses more energy then you get back out of the hydrogen. After all burning hydrogen just turns it back into water, and we can't have more than 100% round-trip efficiency. I could imagine it as a viable storage technology, e.g. if you want to install a solar farm in a remote location you could have it produce hydrogen from the air and sell that.
  • ncmncm 4y ago
    Obviously all conversions involve losses. If you have electric power but need hydrogen, you have to make the hydrogen, whatever the loss. This method has lower loss than others. Probably ammonia will be a better transport medium than hydrogen, but you need hydrogen to make ammonia.
    • saalweachter 4y ago
      Regardless of energy transport, we will be making huge amounts of ammonia using green hydrogen in the future. We need ammonia for fertilizer, and right now we get the hydrogen for that from methane, which can't be the plan long-term. At the moment switching to hydrolysis would double to quadruple the cost of the hydrogen, but eventually falling electricity and rising natural gas prices should invert that. The Haber-Bosch process itself doesn't require petrochemicals, it's just the cheapest way to run it in the current market.
      • ncmncm 4y ago
        "electrolysis". Hydrolysis is a wholly different activity. The intent of the method presented is to make electrolysis energetically cheaper. It might end up financially cheaper, depending on what the apparatus costs, which will of course start out high and come down if used much. Apparently there are practical catalytic processes to go directly from N2 and H2O to NH3 and O2. Everything will compete, and a few processes will win. Tolerance of impurities in the water has often been a problem. Where you have to distill the water first, that increases cost.
• eptcyka 4y ago
  And what would be the use of producing hydrogen when and where it is needed? What's the point of the hydrogen? This might be useful when there's a need to use hydrogen for some chemistry, but for energy purposes, if you don't need to store any energy and you'd be ready to use the energy then and there, what's the point of generating hydrogen?
  • ncmncm 4y ago
    Last year the world used seven hundred million tons of hydrogen, almost all produced from natural gas. In the future the world will use many, many times more, on top of all current uses producing steel, ammonia, and even methane, liquifying for aviation, and pushing underground to produce power from later. The authors have no crystal ball. But need for lots of hydrogen is an easy call, and motivates better ways to produce it. Once produced, it will be used according to the needs of those producing it. The authors' speculations on such use do not bear on the value of the work.