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Renewable Energy: Farm Anaerobic Digesters

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1 to 13 of 13

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    • CommentAuthorowlman
    • CommentTimeMar 10th 2015
     
    I always thought that the main guiding principle for this technology and it's application was initially as a means of disposing of a waste product and turning it into something useful.
    On small and medium farms and horticultural establishments it could usefully serve to dispose of otherwise "waste" matter.
    It now appears we are turning good food producing land into feedstock for industrial sized digesters merely to capitalise on tariffs, or put another way as an investment tool for City get rich quick merchants, who are funding this. All this while food imports rise.
    Is it beyond the wit of man to formulate rules that direct tariffs into true waste management? Is it a case of feed in tariffs distorting the scene.
    It makes me think the Government really don't care and are only interested in ticking boxes before the 2020 GHG emission targets are due, irrespective of it's impact or morality.

    .
    • CommentAuthortony
    • CommentTimeMar 10th 2015
     
    I reckon these things add CO2 to the atmosphere.

    The definition of zero carbon is not helping.
    • CommentAuthortony
    • CommentTimeMar 10th 2015
     
    I reckon these things add CO2 to the atmosphere.

    The definition of zero carbon is not helping.
    • CommentAuthorowlman
    • CommentTimeMar 10th 2015
     
    Yes, and producing Methane, a green house gas I believe. But it's all done in sealed containers you know,--Oh yeah.
    • CommentAuthorEd Davies
    • CommentTimeMar 10th 2015 edited
     
    If the amount of methane which leaks (at least a small amount will, obviously) is greater than the amount which would have been produced by the normal mix of aerobic and anaerobic digestion of this waste then that would be a bit of a problem. Other than that, I don't see how it's a net loss.
    •  
      CommentAuthorSteamyTea
    • CommentTimeMar 10th 2015 edited
     
    Posted By: owlmanOn small and medium farms and horticultural establishments it could usefully serve to dispose of otherwise "waste" matter.
    It now appears we are turning good food producing land into feedstock for industrial sized digesters merely to capitalise on tariffs, or put another way as an investment tool for City get rich quick merchants, who are funding this. All this while food imports rise.
    To be fair you have to put it against the bigger picture of agriculture being global.

    It is a real nonsense to think that a farmer should do anything else than maximise assets and profitability, regardless of who is funding it. They are a business just like any other. Down here in the last few years many dairy farms have changed, a few have got bigger, about 4 supply a local processor and most have stopped (no idea what they are doing now).
    Like any industry, they tend to cluster together, so most dairy is now in Herefordshire, Worcestershire, Avon, Somerset and surrounding areas. This makes logistical sense and for a cheaper product.

    If you look at the amount of land that is available for farming, you will find that there is plenty of it, this site will tell you all you need to know:

    http://www.fao.org/home/en/

    Land area, land usage, productivity etc.

    It has been a long time that agriculture has been run on a local level, some still try, but most are appreciative of the global market place and more than willing to exploit it.

    So I do not see a problem with growing crops for energy per se, I do question why people would do it e.g. is it the most productive use of the land, would a wind farm or a solar farm be better, though they are hampered by planning more than a change of crop.

    As for the 'City' financing farming, that has been going on for decades, nothing new there. Monsanto did not expand into a global corporation on the back of seed sales to local farmers, Birdseye does not survive though the sole use of fast freezing local fish from the NE coast of the USA.

    Farming is big business, with big machinery, big investments and, when done right, big profits.
    it is also very interlinked.
    • CommentAuthorowlman
    • CommentTimeMar 10th 2015
     
    If the AD was scaled to a specific need e.g a dairy farm,or beef rearing enterprise, etc etc. then fine.

    My point is, that we now have the "big boys" riding on the back of these relatively small scale farms, and building 1 and 2 Mw power stations on the same premises, and using specially grown monoculture feedstock to bulk up the deficient amount that the original user produced. It's a money making scam, dreamed up in Lord knows where, endorsed by the Green Party the NFU and anyone else who thinks they may reap some kudos.
    They are deliberately growing "waste", surely that's not how it was intended?
    •  
      CommentAuthorSteamyTea
    • CommentTimeMar 10th 2015
     
    Not really the scam, just normal economics exploiting market imbalances.

    Not saying I agree or disagree with any of it, just the way it is.

    As an example, in the last 4 years, the UK has got up to about 3.9 MW of installed PV. This has been done on the back of a guaranteed payment of around £150 to £200 /MWh. In the last ten years there has been no new nuclear, and probably won't be for 15 to 20 years, the guaranteed payment fort that is just under £100/MWh and as far as I know there is no CAPEX protection on PV, but there is on Nuclear (we will be bailing out Hinkley and the costs are going to be huge).

    I have never been a fan of any state subsidy. The state really does not need to help build the energy sector, what they need to do is tax it on pollution.
    • CommentAuthorowlman
    • CommentTimeMar 10th 2015
     
    You have to set it ST, against the backdrop of 2020 and that was one of the main drivers for the increase in this technology.
    That seems to have been forgotten in the race to "appear Green" . The embodied energy in the growing of "waste" the building of arguably inefficient power producers, the potential for methane escape and other problems, just don't stack up as green technology when used in this manner. Fine as relatively small scale genuine waste disposal, with a useful by product.
    This has nothing to do with global agriculture, it's just smoke and mirrors, masquerading as sustainability. If there is a surplus of agricultural land as you suggest and you want to be green, then plant trees on it. Or alternatively spend the FITs on upgrading the housing stock. But no returns there for the City.
    •  
      CommentAuthorSteamyTea
    • CommentTimeMar 10th 2015
     
    Bit of a cross post there.

    I would not claim that AD is green, just better than coal. :wink:
    • CommentAuthortony
    • CommentTimeMar 10th 2015
     
    I was thinking that most of the carbon that goes in finishes up in the atmosphere as carbon dioxide.
    •  
      CommentAuthorSteamyTea
    • CommentTimeMar 10th 2015
     
    It does, why combustion technology is not very good. It is quite unnecessary too, but it is very cheap.
    • CommentAuthorowlman
    • CommentTimeMar 10th 2015
     
    I think you're on the right trail tony. The gas that comes off the process is "low grade" and the CO2 needs to be scrubbed out before the useful part can be fed into the grid for instance. That CO2, I suspect is just exhausted into the atmosphere. Additionally the process uses a CHP to drive the whole thing, again burning the gas.

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