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Cow dung to power more Dutch homes

  1. Nov 13, 2009 #1

    Evo

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    Interesting, I wonder how cost effective it is and if it's limited to a small area.

    http://news.yahoo.com/s/nm/20091113/od_uk_nm/oukoe_uk_dutch_cows_1 [Broken]
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Nov 13, 2009 #2
    the dutch have no life
     
  4. Nov 13, 2009 #3
    They should just convert all the sewer plants into power plants.
     
  5. Nov 13, 2009 #4
    The article seems to be somewhat garbled, saying the energy will be distributed as heat, which is probably not the case. I suspect the gas will be used to generate electricity.

    At any rate, as it says, methane digesters don't just utilize dung but also "grass and food industry residues". Almost any vegetation can be converted directly to methane. That makes this an eminently renewable energy source. Many varieties of fast growing "weeds", useful for little else, could be used to generate methane.

    The end product, after the useful methane has been harvested, is an excellent fertilizer.

    There is no reason a community wanting to explore this alternative energy shouldn't also make use of the human sewage it automatically generates. As it is, a lot of energy is expended in simply neutralizing it, when, treated differently, it could constitute an energy source.

    IIRC burning methane is not cleaner than current fuels. The main advantage would be decentralization, freedom from fossil fuel distributors.
     
  6. Nov 13, 2009 #5

    IMP

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    What a load of crap. Something smells funny about this.
     
  7. Nov 13, 2009 #6

    Monique

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    I know the zoos are already using manure to generate power for some time.
     
  8. Nov 13, 2009 #7

    Ivan Seeking

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    Heck, we are way ahead of the game here. Washington DC has been running on manure for years.
     
  9. Nov 13, 2009 #8

    Monique

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    On second thought, I also know of neighborhoods where they collect human sewage to generate power. They question how cost effective it is, is an interesting one.
     
  10. Nov 13, 2009 #9

    Ivan Seeking

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    That is the problem. Many of these approaches are viable but not cost effective. As the price of energy continues to rise, alternative sources become practical.

    It has been known since that 1970s that algae was likely a vialble source of biodiesel, but the cost of fuel was simply too low to make the pursuit of algae power practical.
     
  11. Nov 13, 2009 #10

    lisab

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    Has to be the worst idea ever, for the Netherlands! I mean, aren't there windmills and wind turbines *everywhere* there? Imagine the hell to pay, when the 5hit hits the fan.
     
  12. Nov 14, 2009 #11
    :biggrin: No problem, we're used to that. Happens all the time:

    http://www.ceja.educagri.fr/image/produc/315phot07.jpg [Broken]
     
    Last edited by a moderator: May 4, 2017
  13. Nov 14, 2009 #12
    I don't think bio gas faces any of the engineering obstacles that, say, really cost effective solar panels face. It's pretty low tech. I think the main reason it isn't being developed more aggressively is that it doesn't represent progress in pollution control:

    http://en.wikipedia.org/wiki/Methane

    People hope the switch from fossil fuels to alternatives will eliminate contributions to the greenhouse effect.
     
  14. Nov 14, 2009 #13

    Ivan Seeking

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    If it was cost effective it would be pursued. In fact this option has been "in the news" since I was a kid - long before global warming was even an afterthought. It has never been cost effective except perhaps for the rare cases of large farms.

    Low tech often means labor intensive. I have always assumed that this is why it is used mainly in third-world societies where the cost of labor is exceedingly low. For example, I remember seeing a spot on this where all of the kids in a village would go around each morning collecting the cow doo. The energy return on the labor invested was very low at best, but it was enough to provide limited power for a couple of hours - IIRC, it was enough to run a 5 hp generator for a few hours a day. Compare that to our cost of 13-18 cents per KW-HR. A few hours at perhaps 2500 watts [net power yield] is worth about a buck.
     
    Last edited: Nov 14, 2009
  15. Nov 14, 2009 #14

    Moonbear

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    There's a difference between being cost effective and profitable. It very well may be cost effective, especially if you can charge on both ends -- charge the farmers or other sources of waste (i.e., restaurants) a nominal waste disposal fee that is less than they'd pay to a waste disposal company that would just landfill the waste, and charge the consumers of the gas or electric obtained from the source. Afterall, the raw product isn't something you need to spend money mining or drilling or growing to obtain, but just collect waste that people already pay to have hauled away.

    It may not be hugely profitable to be appealing to private industry. But, it might suffice to at least break even for a public utility to operate.

    Environmentally, again, this is something that's going to sit around generating methane gas anyway, so if you can collect it and harvest it (and perhaps burn the residual organic matter to further generate energy), it seems better to turn it into useful energy than to just let it be emitted into the air. The potential downside would be if the energy production means the remaining solids that would not convert to methane gas end up being used for energy instead of being composted as fertilizer to return nutrients to the soil (the Dutch have a lot of cows, but they also have a lot of tulips that need to be fertilized).
     
  16. Nov 14, 2009 #15

    Ivan Seeking

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    My point was not that its unworkable. The point was that it has always been difficult to do this cost effectively.

    Also, we have to be careful when we talk about something being cost effective when it depends on petroleum for the process. All of those pumps and delivery trucks use cheap energy obtained from petro. So there is not only the issue of financial cost, but also hidden energy costs. It is possible to profitable but a net energy sink.

    Many people argue that corn-ethanol is a net energy sink.
     
  17. Nov 14, 2009 #16

    Moonbear

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    I think you have to think about it from the perspective of what the situation would be if this particular fuel source was not used for energy production at all. In the case of cow manure, it's still going to be produced, and the trucks are still going to run to haul it away. Except now it may mitigate some of that energy consumption by being tapped as a source of energy. So, even if it doesn't break even, there can be some benefit to it.

    On the other hand, with something like corn ethanol, if there were no buyers for that corn, it wouldn't be planted. If there are no buyers for manure, the cows are still going to poop.
     
  18. Nov 16, 2009 #17
    Any process or procedure is bound to be clumsy and overly expensive at first. It can take decades of experience, and input from a couple generations of clever problem solvers before something is streamlined to the point it's viable. Or, if you assemble enough people who are willing to drive forklifts through walls (you remember that story you told), it can go much faster.

    A methane digester is a very simple plumbing apparatus designed to take advantage of an automatic biological process, unlike, say, an oil refinery, which is a lot more complex. There aren't any major engineering hurdles to jump in going from waste to methane: it happens by itself. The task is merely to contain the process and collect the results. With human waste you don't need kids to gather it since it's already flushed to concentration points. (The sewer mains themselves already function as methane digesters and, interestingly enough, a free source of gas is as far away as the other side of the water trap in your toilet.)

    I think moonbear is probably right in viewing conversion to bio-gas more as a good solution to getting rid of human and animal waste, which is going to happen and produce methane anyway. A minimum goal would be for sewage treatment plants to produce enough energy to operate themselves. Producing enough to put some into the grid would be a great bonus if it's feasible.
     
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