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The price of pellets in New England

Post in 'The Green Room' started by woodgeek, May 11, 2011.

  1. woodgeek

    woodgeek Minister of Fire

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  2. Slow1

    Slow1 Minister of Fire

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    Nevermind pellets - all wood (including firewood) would have been in shorter supply I suspect. However, burning at 25% efficiency just really doesn't cut it in my opinion no matter the affect on costs. Even the proposed 40% minimum seems rather low to me. Come on folks - quit trying to burn water ok?

    Sure it may be "carbon neutral" in the sense that the trees can be re-grown, but why truck in (burning diesel) three times as many loads as needed to generate the power? I don't think that is very 'carbon neutral' is it?
  3. btuser

    btuser Minister of Fire

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    40% kills me. I was just at an old rusting biomass powerplant that hasn't been fired since 2005. Still getting subsidies, promising jobs, taking up space. Every few years a new person comes along to buy it, kinda like a Restaurant that keeps the same name but different members of the family are the owners, because the last tax cheat went back to the homeland.
  4. Slow1

    Slow1 Minister of Fire

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    The thing is that I do believe that it could be possible to design an economically and environmentally viable biomass power plant. I expect the problem is the scale they want to go with - utilizing all the energy produced in an efficient manner requires utilizing the heat as well as the electricity in a reasonable way (i.e. don't just make up an excuse to use it). I suspect the reality is that you end up primarily using the heat and any electricity becomes a byproduct of the process. As I understand it, the efficient biomass plants in Europe heat water/steam to use for local area heating or industrial use, not just electric power generation. Rather hard to pipe that long distances, but for local use it works out well.

    Then of course the question of fuel comes in - as we all know here, dry wood (or other biomass) burns best, but imagine the space that would be required to process and store 3 years worth of fuel for one of those plants! ha. Ok, sure, use some of the heat produced by the plant itself to dry the fuel out, but then that effectively subtracts from the overall efficiency...

    We are able to achieve reasonable efficiency in our biomass burning due to the fact that we have small scale systems utilizing the heat right at the source and can dry out our fuel (or buy dried out pellets as the case may be). Very different picture when you scale up I suppose....
  5. woodgeek

    woodgeek Minister of Fire

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    I am assuming that the 25%/40% number is the ratio of input BTUs to output electricity--IOW it includes the thermodynamic penalties inherent in
    any heat engine. 25% might be close to the theoretical limit is the exhaust temp is low or the steam turbine is not state of the art. For burning 'waste'
    that has a low cost per BTU, I'd have to see the lifecycle cost analysis on upgrading the boiler or the turbine...low cost fuel favors low eff economically.

    One of my pet peeves is how folks on both sides of the green story abuse the nom 50% thermodynamic hit in converting heat BTU to electrons. I.e. the
    fossil generators always compare their input heat BTU to the equivalent wind/solar power BTU if you ran the elec through a resistance heater, and say that
    wind/solar provides <1% of 'primary energy' rather than saying >2% total US electricity. On the other side, the greens look at delivered elec Kwh versus
    input BTU, and say our fossil power system is <40% eff (including the thermo hit) to suggest we should scrap the whole thing and buy PV panels.

    If the thermo eff is included in the 25% in the article--the noisy greens killing the MA plant are guilty of the latter.

    Me, I am largely heating my house with the reciprocal thermo factor--I get a COP=2+ from my HP running on wind power elec.
  6. woodgeek

    woodgeek Minister of Fire

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    Of course, Slow1 is right--in a perfect (i.e. free capital equipment) world we would have 100% combustion eff, take 40% out as elec and deliver the other 60% as process heat to a factory or district heating to the neighborhood. Unfortunately, I think the suburban model of the US, versus the higher density overseas makes district heating harder here, in the sense that the parasitics and piping costs would be way too high.

    Micro-CHP anyone?

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