carbon calculator

Hi

Has anyone a link to a comprehensive carbon emissions calculator? I've tried several but they all want to know your electricity consumption (0kw) and none i've seen include wood heat in any form. :x

Just a simple listing of carbon emissions from propane, diesel, gasoline and wood consumed would do me well. This is all to make me feel even better than i already do about the way we live in our household. Any ideas or input welcome.

thanks

Comments

  • BB.BB. Super Moderators, Administrators Posts: 31,085 admin
    Re: carbon calculator

    I know that this is not what you asked for--but if you have multiple fuels available it is nice to compare prices based on BTU values of different fuels.

    http://www.hearth.com/econtent/index.php/articles/fuel_cost_comparison_calculator/?id=47_0_1_0_M7

    Here is a carbon calculator that includes Natural Gas and Heating Oil:

    http://carbonfund.org/site/pages/calculator/

    Here is another carbon calculator that is in the MKS units:

    http://www.nef.org.uk/energyadvice/co2calculator.htm

    So far, I have not found anything that says burn a pound of wood gives xx lbs of CO2... And most sites treat burning wood as being "carbon neutral"... However, you can probably equate the burning of wood with that of coal (and, in fact, it is probably worst than coal as there is, typically more water in wood which would tend to reduce wood's thermal efficiency).

    Moving some numbers around from these various websites:

    1 tonn of coal (metric ton ~ 2,200 lbs) = 2419 kG of CO2 or 1.1 lbs of CO2 per 1 lbs of coal...

    2000 lbs of coal ~ 20 million BTU

    17.5 Million BTU per Cord of Hardwood
    11.3 MBTU per Cord of Softwood

    So, as a VERY ROUGH ESTIMATE (based on equal thermal output between coal and wood: i.e., that 1 MBTU of Coal and 1 MBTU of wood output the same weight of CO2--just a SWAG):

    2,200 lbs of CO2 per 20 million BTU of Coal (1 ton of coal)
    2,200 lbs CO2 / 20MBTU of coal * 20/17.5 BTU/BTU for Hardwood = 2,500 lbs CO2 / 20 MBTU of Hardwood
    2,200 lbs CO2 / 20MBTU of coal * 20/11.3 BTU/BTU for Softwood = 3,900 lbs of CO2 / 20 MBTU of Softwood

    2,500 lbsCO2/20 MBTU * 17.5 MBTU/20 MTBU/Cord = 2,190 lbs of CO2 per Cord of Hardwood
    3,900 lbsCO2/20 MBTU * 11.3 MBTU/20 MTBU/Cord = 2,200 lbs of CO2 per Cord of Softwood

    Be warned--all of these numbers are probably not accurate to more than the first digit and are based on the estimate that burning coal and hardwood are approximately equal in their carbon production. My guess is that burning wood may even release more CO2 than coal--but these calculations can at least provided an estimate.

    From here, a cord of wood weighs approximately 2-3 tons (seems to agree with my number above that a cord of (hardwood) is about equal in BTU's from a ton of coal):
    A pile of wood 4 feet by 4 feet by 8 feet neatly stacked as shown in the diagram. This gives a volume of 128 cubic feet, although there may be only 80 to 90 cubic feet of actual wood allowing for space between the stacked pieces. Bulk firewood is usually sold by the cord or fraction of a cord. A cord of wood, depending upon the type of wood and its dryness, generally weighs between 2 and 3 tons. As a rough guide, it will yield the heat equivalent of a ton of coal or 200 gallons of fuel oil. A typical full size pick-up, bed level, will hold about half a cord.

    And here is a link on BTU's from a cord of wood (over 25 species of wood listed):

    http://www.daviddarling.info/encyclopedia/C/AE_cord.html
    Species|Density (lb./cu.ft.)|Weight per cord (lb.)|BTUs per cord(millions)|Recoverable BTUs per cord millions)|Units needed to produce 1 million BTUs
    hickory 50.9 4327 27.7 19.39 BTU/Cord 0.052
    ...(best to near worst)...
    white pine 26.3 2236 14.3 10.01 BTU/Cord 0.100

    There are just too many variables to be more accurate (hard coal/soft coal/dry wood/wet wood/species of wood/temperature of fire/etc.)...

    Have Fun!
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: carbon calculator

    how efficiently the wood stove re burns the smoke, as many modern efficient units do.
  • BB.BB. Super Moderators, Administrators Posts: 31,085 admin
    Re: carbon calculator

    From the links above--burning efficiencies:

    http://www.hearth.com/econtent/index.php/articles/fuel_cost_comparison_calculator/?id=47_0_1_0_M7
    Oil and Gas Furnaces
    Older Models - 50% to 70%
    Newer Models - 70% to 85%

    Wood Hearth Products
    Open Wood Fireplace - 5% to 25%
    Older Non-Airtight Stoves - 25% to 35%
    Older Airtight Stoves - 40% to 60%
    Newer EPA Stoves and Fireplaces - 65% - 80%

    Pellet Stoves
    Older Pellet Stove (pre-1994) - 50% to 65%
    Newer Pellet or Corn Stove - 65% to 80%

    Gas (LP or Natural) Hearth Products
    Vented Gas Fireplace Logs - 5% to 15%
    B-Vent Gas Fireplaces and Stoves - 35% to 65%
    Direct-Vent Fireplace and Stoves - 40% to 80%
    Vent-Free Fireplaces, Stoves and Logs - 90%

    Coal Heating Systems
    Older Coal Furnace/Boiler - 50% to 65%
    Modern Coal Stove - 60% to 80%
    Stoker or Hopper-Fed Stove - 70% to 85%
    Electric Resistance Heat - 95% to 100%

    The other link where I got the wood heating BTU values has a bunch of links about stoves/fireplaces and such... And in one of those links, they say that a catalytic wood stove adds about 10% efficiency (replace caytalyst about every 6 years / 10-12,000 hours).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: carbon calculator

    ah...
    my stove here says 70%, and it does refer to 4.4 grams per hour of emissions: http://www.lopistoves.com/product_guide/detail.aspx?id=208#Specs

    the liberty stove is the one i wish id gotten is rated at only 2.6 grams per hour. (still 70% efficiency)
    http://www.lopistoves.com/product_guide/detail.aspx?id=211#Specs

    these models use a pretty effective recirculation system and natural convection (no catalytic converter as i was just telling crezwer). im guessing the lesser emissions from the bigger stove might be due to more heat (bigger firebox) equaling more airflow, so more convction on the outside, and more air recirculation inside.
  • System2System2 Posts: 6,290 admin
    Re: carbon calculator

    I just looked up: 1 pound = 453.59237 grams
  • BB.BB. Super Moderators, Administrators Posts: 31,085 admin
    Re: carbon calculator

    A simple conversion between kg and lbs:

    1lb/.45359237 kg = 2.20462262 ~ 2.2 lbs/kg

    Regarding emissions, it appears that at least half of the 2.6 grams/hour (if not all) is particulate emissions.

    If you 66,800 BTU's / hour for Matt's link below, then CO2 emissions (1/2 hardwood 1/2 soft wood) would be, approximately:

    0.0668 MBTU's per hour / 14.4 MBTU's per cord * 2,200 lbs of CO2 per cord =~ 10.2 lbs of CO2 per hour (at full heat).

    Again, the above numbers are very approximate values for CO2 emissions...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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