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Power Plant Fueled By Nut Shells

Posted by simoniker on from the don't-have-to-be-nuts-to-work-here dept.

sbszine writes "The Sydney Morning Herald is running an article about a green power plant that runs on the discarded shells of macadamia nuts. The power plant, located in Gympie, Queensland, is expected to reduce greenhouse gas emissions by around 9500 tonnes in its first year of operation."

16 of 297 comments (clear)

  1. Some times you feel like a nut... by Powercntrl · · Score: 5, Funny

    ...sometimes a volt.

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    DRM is like antifreeze, to the MPAA/RIAA it's sweet, to the consumers it's poison.
  2. Reduction in Co2? by zefod · · Score: 5, Interesting

    My guess is that they would burn the shells of these nuts, right? This produces carbondioxide, so how does this reduce CO2?

    1. Re:Reduction in Co2? by zmooc · · Score: 5, Informative
      Wrong. The only thing that matters in this context, is the percentage of CO2 in the atmosphere. While in the long term, burning plants would indeed not introduce any new CO2 into the biosystem. The only problem is that it is generally assumed it takes about 100 years for nature to create a balance between CO2-production ans CO2-consumption by plants. Just compare it to a closed system in a box with a plant and a device burning it's seeds; the plant will consume the CO2 a lot slower than the device can produce it so the CO2-level in the box will definately go up just like a sink will fill when the tap runs faster than the drain can put up with.

      But in the long term it's always better to burn plants instead of oil since burning oil introduces new C into our biosystem while burning plants only raises the C-level in the atmosphere but not in the biosystem.

      By the way, this only works if you assume each burned plant will be replaced by a equivalent plant. Burning more plants means the average age and therefore size of plants will decrease and therefore the amount of C these plants can hold will also decrease. And then even the space that's available for plants is declining.

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    2. Re:Reduction in Co2? by misterpies · · Score: 5, Insightful

      Wrong wrong wrong. A nut grows in a single season. The carbon in the nut can only come from CO2 in the atmosphere. Therefore burning nuts is carbon neutral over a single nut-growing season.

      Similarly, I fail to follow your example of a plant in a box. OK, while the seeds are actually aflame CO2 will be produced faster than it's being absorbed. But overall, the amount of carbon in the system is constant: anything which is not in the plant is in the atmosphere. Therefore so long as you burn the plant no more quickly than it grows, you'll never end up with a higher CO2 concentration than when you started.

      Your argument only applies if you start burning something which has been growing for decades -- eg old-growth forest -- in which case you're releasing CO2 that took decades to remove from the atmosphere. But so long as you burn material grown only over, say, the last year -- eg fast-growing bamboo -- then the net amount of CO2 released into the atmosphere over that year must be zero.

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    3. Re:Reduction in Co2? by famebait · · Score: 5, Informative
      Just compare it to a closed system in a box with a plant and a device burning it's seeds; the plant will consume the CO2 a lot slower than the device can produce it
      What makes you believe that? Are you assuming that the plant produces seeds at a diminishing rate, or that burning a seed releases more carbon than was put into building it? Because something doesn't add up here.

      You are describing a closed system with a net production of carbon. If you have one of those you could be very rich indeed.
      Just like a sink will fill when the tap runs faster than the drain can put up with.
      That's not a closed system.
      The only problem is that it is generally assumed it takes about 100 years for nature to create a balance between CO2-production ans CO2-consumption by plants.
      That's a little out of context. Yes, if you completely cut down a forest, it takes a long time until there is once again the same amount of biomass contained on that area. But we're not _removing_ the ecosystem and waiting for it to return here, we're burning a nutshell in stead of allowing it to rot. The tree is still there, and it doesn't take a 100 years to replace a nutshell. If you burn a billion shells a year and produce a billion too, you have a net emission of zero. You're basically just extracting solar energy, the shells and the carbon are just carriers in the process.

      There would be an minor initial 'cost' in that you're shortening the cycle a little, releasing the carbon more shortly after it's trapped compared to natural decomposition. So you get an initial emission over the first year or two after start up, as the 'cache' of decomposing shells releases its carbon at the same time as new shells are burnt immediately. But after they're gone you'll be running in balance. Or you could avoid that too by imitating nature and storing the shells a couple of years before burning them.
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  3. Nuts by CGP314 · · Score: 5, Funny

    The power plant, located in Gympie, Queensland, is expected to reduce greenhouse gas emissions by around 9500 tonnes in its first year of operation.

    In an unrelated story, macadamia nut consumption is up 10,000%

  4. This is a failed experiment... by shadowcabbit · · Score: 5, Funny

    ...after trying to harness the power of looney, wacky, zany, or crazy, they succeeded only in making use of nutty power.

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  5. Now if only... by thesuperjason · · Score: 5, Funny

    we could develop a plant that converted empty XXXX (local QLD beer) cans into usable power. Now that'd be something! Well, it'd ease my concience anyway...

  6. Efficiency? by brucmack · · Score: 5, Interesting

    It would be nice to know what the cost efficiency of this plant is... seeing as how this has always been the big problem with "green" power.

    Also, is there any inherent advantage to using macadamia nuts rather than some other biomass?

    1. Re:Efficiency? by Thomas+M+Hughes · · Score: 5, Insightful

      The main advantage in this case is that they were already growing the macadamia nuts in the area, and they were already shelling them. The shells were then, previously, just being discarded. Because the "fuel" for this power plant was previously considered "waste", the result is much more efficient economically then a lot of things.

      Think of it like this:

      macadamia = shell + nut

      Old equasion:
      profit = sale of nut - disposal of shell

      New equasion:
      profit = sale of nut + electricity generation from shell

      This, of course, assumes that the electricity produced from the shells can be sold at a profit that is greater than the cost of disposing of the nuts. From everything I've heard here, the power plant is relatively inexpensive to construct ($3 million), as such, the cost of electricity generation probably won't be that great. However, we'd need more data to say that for sure.

      As an added bonus, the CO2 output is neutral over a single year. Ie: shell takes 1 year's worth of CO2 in as it grows, we then burn it, and 1 years worth of CO2 is released. Comparatively, coal takes in X number of years (thousands of years ago), we burn it, and it releases it into the atmosphere now, resulting in a gain in CO2 in the atmosphere.

      Keep in mind that this means we won't be powering the entire country with macadamia nut shells. This plant only powers 1200 homes. The brilliant aspect of this is that its powered off of waste that was already present in the region. This would be similar to a facility that produces corn creating a power plant next to it that is fueled by corn husks and the unedible parts of the corn. Its simply just a comparative advantage. Its fuel that you have here and now, so there are little to no transportation costs. Even if another biomass is more efficient, you'd have to transport it to the generation facility, decreasing its overall efficiency.

      Ideally, for something like this, you'd build lots of smaller facilities, wherever burnable bio-waste is produced. 1200 homes here, 1200 homes there, mix it with some solar and wind generation, and other alternative energies, and eventually the fossil fuel habit might be kicked.

  7. Energy in/Energy out. by CGP314 · · Score: 5, Insightful

    How much energy goes into getting the nuts out of the shells in the first place? I remember going to a macadamia nut farm in Hawaii once. They had a prize of a lifetime supply of macadamias if you could get a nut out of a shell without using a saw. I tried smashing it with a rock with no luck. Apparently, no one had ever collected the prize.

  8. Rogue Nation by Potor · · Score: 5, Funny

    How did they get the technology to split the nut?

  9. Thats nothing by mphase · · Score: 5, Interesting

    Watch this process turn your garbage into oil.

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    vampirical
  10. Higher usable energy by moscow · · Score: 5, Informative
    According to ABC Queensland , Macadamia shells are actually prime material for electricity generation - they burn more cleanly than coal, and produce more energy.

    Of course, natural decay of the shells would release the CO2 in any case.

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  11. Re:The article doesn't say... by madbastd · · Score: 5, Informative
    But does anyone know why they chose macadamia nuts? Seems a very strange choice.
    Macadamia trees are a native plant in that part of Australia, and grow very well. There's a large macadamia nut industry there, which was throwing out huge amounts of nutshell.
  12. Hello, 1970? by heironymouscoward · · Score: 5, Interesting

    This is the scene. I'm a young boy, 8 years old, in Dar-es-Salaam, capital of Tanzania. On the horizon sits a squat building with a tall tower, belching some kind of gray-white smoke.

    "Mummy, what's that?"
    "It's a power plant, Heirony"
    "What does it burn, Mummy?"
    "Caschew nut fruits, Heirony"

    The caschew nut grows as a small nut on a huge fruit which is rich and oily. For each of those tiny caschew nuts, a fruit weighing perhaps 500gr is grown, harvested, and then discarded.

    In Tanzania in 1970, and probably still today, these fruits were dried and then burnt for power. Glad to see that some third-world technology had finally made it to the rich west.

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