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Boeing Installs World's Largest 'Reversible' Renewable Energy Storage System (computerworld.com)

Posted by timothy on from the from-suck-to-blow dept.

Lucas123 writes: Boeing announced that it has installed a first-of-its-kind 50MW Solid Oxide Fuel Cell (SOFC) system on a naval base in Port Hueneme, Calif. The fuel cell system, which can scale to 400KW, is unique in that it uses solar power to generate hydrogen gas from seawater, which it then stores until it releases the gas into a fuel cell stack to produce electricity, heat and water. Because the system can both store energy and produce electricity, Boeing is calling the fuel cell system "reversible." The Navy's Engineering and Expeditionary Warfare Center is testing the fuel cell system on a microgrid to determine its viability for use at both remote bases and during overseas military missions.

4 of 120 comments (clear)

  1. Sounds good... by jamstar7 · · Score: 1, Interesting

    That is, if you're near a large supply of readily accessible water. Even with scavanging the water vapor off the fuel cells, there will be losses. And it's likely to use a lot of water to start up. Here in the desert, water is a BIG issue.

    50 kw per hour is 36 megawatts a month. Enough to power a small town. And this tech scales easily? It could be an answer for said small towns, a few 50-400kw plants should do them. I like decentralised energy generation. Less choke points. Less transmission infrastructure to maintain.

    --
    Understanding the scope of the problem is the first step on the path to true panic.
    1. Re:Sounds good... by Hognoxious · · Score: 4, Interesting

      "Kilowatts per hour" doesn't make any sense at all. Watts are already a rate - joules per second.

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
    2. Re:Sounds good... by Solandri · · Score: 3, Interesting

      The Gibbs free energy of water is -237.14 kJ/mole, or (at 55.6 moles/liter) 13.184 MJ/liter, or (in electrical terms) 3662 kWh per ton of water. That's how much energy you gain combining hydrogen and oxygen to form water (H2 and O2 have a Gibbs free energy of zero). So about a third the energy density of gasoline (negative energy density actually, since the end product is water).

      An average U.S. household uses about 13 MWh/yr, so if were to all come from hydrogen and oxygen, they would form about 3550 liters of water in a year, just under 10 liters a day. Or put another way, a 1000 MW version of this would generate about 273 tons of water per hour. Divide by the efficiency to get how many tons of water are needed to separate into hydrogen and oxygen.

      This actually gets to another off-topic synergy I've been wondering about. Evaporative distillation takes more energy to desalinate seawater than reverse osmosis. So most of the solutions thus far have been to build big reverse osmosis plants. But that's purely an energy analysis. It ignores the cost of the energy. Evaporative distillation relies almost entirely on thermal energy. Well, at power generation plants, heat is considered a waste product - it's free energy.

      For places where water is in short supply like California, why isn't every power plant being built near the sea, where they can use seawater for cooling? It'll have to be a two-stage cooling circuit with a heat exchanger to prevent corrosion from affecting power generation systems. But that's already what's used in nuclear plants so there's no new engineering which needs to be developed there. Do this and 1/3rd the energy from burning coal, oil, or nuclear can go into generating electricity. The remaining 2/3rds of the energy can go into desalinating seawater.

      The thermal energy cost to desalinate is on the order of 80 kWh/ton. Or 288 MJ/ton. So your 1000 MWe power plant (which is generating about 2000 MW of thermal energy) has enough thermal energy to desalinate seawater to produce 3.5 tons of fresh water per second.

  2. Largest of its type only by hackertourist · · Score: 5, Interesting

    Reversible energy storage systems have been around for a while. Pumped water storage scales to GW levels with 70% efficiency, but depend on specific geography.
    Another scheme is to use an electric locomotive to push rail cars up a hill, and use motor braking on the downhill run to extract the energy again.

    Storage in hydrogen is less efficient: electrolysis is 70% efficient, a fuel cell is 40-60%, so chain efficiency is around 35%. The advantage is it's scalable and can be made portable (which is why the DOD is interested).