carbon footprint and heat

I don't remember the study but it went like this for CO2 production per BTU;
Pellet stove - best
wood - almost as good
Natural gas - not so good
Propane - almost not so good
Electricity - very poor
Green Heat
from the report;
Per dollar invested, wood or pellet stoves and boilers can reduce more carbon emissions than any other heating energy source. In a significant portion of the middle of this country, a wood or pellet stove can supply 80 – 100 percent of necessary heat for small and mid-sized homes. Installing a high quality wood or pellet stove will cost about $2,500 to $3,500. That investment can easily reduce your carbon footprint by two to four tons per year, or 10 – 20 percent of your entire emissions. Few investments of this size can deliver such a big reduction.

I am a big fan of wood pellets; since we have a local saw mill that produces them, they have a very small carbon footprint and produce less CO2 from the flue for the same heat as any other heat source.


The Salzburger Institute for Urbanisation and Housing (SIR) released a study for the Energy Efficiency Day which showed biomass pellets offer households the most efficient way of reducing their carbon footprint. By switching from a heating oil system to a pellet heating system, the average Austrian household can avoid up to 10,000 kilograms of CO2 emissions. This is more than the emission reduction potential of all other renewables and efficiency measures.

Using highly efficient insulation materials throughout the home, which would cost on average 4 times more than a biomass heating system, would only offer CO2 savings of around 3300kg.

Geothermal heating systems are an attractive alternative to heating oil, but they too perform weakly compared to biomass. This is due, the SIR says, to their reliance on relatively large amounts of electricity - which, in Austria's electricity mix, is obtained mostly from fossil sources:

I think that would be another factor that would be great to have in the mix: cost.

It would be cool to see for each of the forms of heat, both the CO2 released into the air, and the cost. And I think that by limiting it to a state like montana, then you don't run into the stuff where people argue about the info because they live in florida.

This page says

Natural Gas $461 per year
Electric $1,541 per year
Propane $1,178 per year
Heat Pump (Air Source) $963 per year
Heat Pump (Ground Source) $440 per year

It seems like the electric could be converted to total BTU count, and that could be used to come up with something for conventional wood stoves.

This is interesting:


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paul wheaton wrote:I wonder if there can be such a thing as a "typical home" in montana.
Then, I wonder about how much CO2 goes into the atmosphere if you heat with natural gas, electricity or a conventional wood stove.
Anybody know anything like that?

With electricity, it seems that the total amount of CO2 production would depend greatly on how the electricity was generated. Nuclear/Hydro/Wind/Solar would have practically none while Coal/Oil/Natural Gas would have more. Another thing to consider is when the carbon you are releasing was sequestered. For a wood stove, you are probably releasing carbon that was sequestered when Bill Clinton was in office. If you are burning natural gas you are releasing carbon that was sequestered when there were dinosaurs roaming around.

EDIT: It looks like Montana's electricity is about 2/3rds from coal and 1/3 from hydro:

http://instituteforenergyresearch.org/media/state-regs/pdf/Montana.pdf

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From the first chart it says wood is $250 per cord, but my experience is closer to $150 per cord.

Here is my super rough math so far (I am thinking mostly about ratios for a graph, not anything in exact units):

cost

100 electricity
33 natural gas
25 wood
5 easy-to-use rmh
2 extra efficient rmh


CO2

100 electricity
18 natural gas
1.5 wood
0.3 easy-to-use rmh
0.1 extra efficient rmh

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Rocket stoves and other wood burning appliances, commonly use materials that may otherwise end up in outdoor burn piles. Most of the wood burned on this island, is burned in giant slash piles after forestry operations.

Before the piles are burned, people go in with chainsaws and scrounge firewood. Their heating has a very small environmental footprint.

I've been thinking a little on the same lines myself the last couple days but from a bit of a different angle given my situation. I don't heat at all. Zero. But this means during the winter I am constantly boiling water for tea (and I've gotten strung out on coffee again) and eating way way more. Like I probably eat somewhere around 3600 (k)calories a day in winter to keep warm. Now if all of those food calories were industrial ag (they aren't but some are) I'd have to multiply that number by 14 or so to get the number of fossil fuel energy calories I burn. I wonder if one would be better off sticking to 2200 calories a day and rocket mass heating with wood. Like from an energy and carbon footprint standpoint.

Interesting conversation.

paul wheaton wrote:This is interesting:


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How can electricity have a 98% conversion efficiency, if it's sourced from a grid with losses that exceed 30%?

I really don't know how to do "apples to apples" when comparing entire systems of different technologies.

-Erica

I am not certain where the 98 percent comes from there, but there is another article about efficiency he shows this chart which breaks it up. So the conversion efficiency of all the sources combined is 34 percent. It has been impossibly hard to get to the bottom of everything that needs to be summed for a proper carbon footprint analysis. It seems clear that burning coal is leading the way in emissions, and that almost anything else would be a more ecological substitute. Other than that it's tough to draw too many sweeping generalizations because of local availability and other variables.

So I don't have any nifty charts. But I have been doing a little bit of research and found that the average american household consumes 47,453 cubic feet of natural gas.

Using the conversion of 1.027 therms = 1 cubic foot. The average single-family home uses 48,734 therms a year. The U.S. EPA estimates that 0.005 metric tons CO2 are emitted per therms of natural gas burned.

Using the conversion of 1 metric ton per 2204.62262 pounds, this equals approximately 2.268 pounds per therm burned. U.S.

THUS - 48,734 therms x 2.268 pounds = 110,528.7 = 55 tons of carbon emitted per year
(source)



AND I also did some research into average car carbon emissions:

Vehicle Travel: 12,000 miles per year (average)/ 27.5 (average MPG apparently, seems high to me) = 436.36 gallons x17.68 pounds of CO2 = 7,714 lbs = 3.8 tons of carbon emitted per year
(source)


SOOOOO, from the charts in some posts above we came to the conclusion that heating with a rocket mass heater gives off about 1% the CO2 emissions that natural gas does. SOOO, 1% of 55 tons is about 1 ton. Technically only .55 but we will round up to one for the sake of argument.

SO in conclusion, a household will save 54 tons of carbon emissions a year by switching from natural gas heat to a rocket mass heater..

ANNNNDD according to my car carbon emissions calculations, Replacing natural gas with a rocket mass heater will cut carbon emissions more than taking 12 cars off the road.! (54 tons/3.8 tons=14) so it would really be more like 14, but we will just say 12 to account for any other mathematical errors I have possibly made.

BOOM!

Awesome, Cassie.
I bet when you were in math class, you never in a million years expected you would be asked to do that calculation in real life.

-Erica

Nope, I can definitely say this was the first math I've done besides calculating my tip in about 6 years. Hahah

Erica Wisner wrote:
How can electricity have a 98% conversion efficiency, if it's sourced from a grid with losses that exceed 30%?

I really don't know how to do "apples to apples" when comparing entire systems of different technologies.

-Erica

It looks like the chart is measuring efficiency starting from the fuel sources delivery to your home. Inefficient electrical circuits throw off heat as a waste product. So in order to make the most efficient electrical heater, you just need to create the least efficient electrical circuit possible. So the 98% makes sense.

What does a ton of wood look like? In chords?

here is a chart showing the weight of different woods both green and dried.

Another with diff species here.

To answer your question a ton of wood usually looks like less than a single chord.

This is where you get into looking at your "typical" firewood, rather than a statistical average figure.
We burn pine, larch, and fir - these are similar to cherry or fruit-woods in density, about 1.4 tons per cord.

We have friends in California who burn their local scrub wood - oak and madrone - almost 2 tons per cord.

We have friends in New England who burn a lot of birch, beech, spruce, hemlock, pine - now they might average 1 ton per cord.

A US ton is 2000 lbs, a metric tonne is 2200 or so (1000 kilograms).
I like this site's explanations of firewood energy content and so on: http://www.chimneysweeponline.com/library.htm

Measuring it by the ton rather than the cord would probably be fairer, value for value. Except it's even more valuable to get premium dry-seasoned wood. And that's lighter, by volume, than the same wood delivered earlier and greener. So unless you have a moisture meter or a big shed, volume measurements leave you freer to discuss quality and price.

Likewise, I believe most of the figures we've used for "average household consumption" are based on taking the entire nationwide consumption and dividing by the number of households - they don't take into account the difference between a household that heats with natural gas, vs. one that doesn't (but might cook with it, for example). The meter doesn't know what you do with the stuff.
I don't even know if they remembered to factor out the natural gas buses and stuff.

Getting more accurate numbers on this stuff is really hard. That's part of why it is taking so long for the public to wrap their minds around it. Up to about 100 years ago - a time that still affects our family patterns today, as people who were children then probably shaped the neuroses of people you know - it almost literally didn't matter. There was plenty of world to soak up and dilute our worst blunders, and a septic-tank-next-to-the-well error likely would only affect a few families. But we were already on a trajectory of growth and industrial expansion, which led to the first experience of a world almost entirely under the influence of human efforts. Except it's at about the same level of collective finesse as a toddler's "control" over its dinner.

-Erica

Cassie Langstraat wrote:Using the conversion of 1.027 therms = 1 cubic foot. The average single-family home uses 48,734 therms a year. The U.S. EPA estimates that 0.005 metric tons CO2 are emitted per therms of natural gas burned.

Can you find a source for the 48,794 therms per year for heating number? It seems WAY high based on what my heating bill for January (122 therms in Indiana where the low was -7F).

Also, this website says 922 therms per year is average.

The state of New Hampshire says that on average a therm of natural gas costs about $1.26 [website] which would mean the average New Hampshire household would have, on average, a $12,000 a month heating bill for the five months heating is needed.

This chart shows average btu per household. A therm is 100,000 btu, which roughly corresponds to The energy created from burning 100 cubic feet of natural gas. So average house Uses between 800 and 1200 therms a year roughly.

If 48,794 cubic feet of natural gas is used then (48,794 ft / 100 ft = 487.94 therms ) ( 487.94 therms x $ 1.26 = ~$615 was spent on natural gas)

According to this list of conversion factors

CO2 Pollution of Fossil Fuels

Pounds of CO2 per billion BTU of energy::
Coal 208,000 pounds
Oil 164,000 pounds
Natural Gas 117,000 pounds

If this were accurate then 488 therms x100,000 BTU =48,800,000 BTU created with natural gas Which is equal to .0488 billion BTU
( .0488 billions x 117,000 lb = 5709.6 lb / 2204.667lb = 2.58 tons of carbon.






This is interesting too, shows who spends how much on energy according to region. From this it would have to be figured roughly how much of this was spent on heating in particular.




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I need to announce something. I fucked up.

How I did that: In my research, I trusted a conversion rate from this website. It told me 1 cubic foot = 1.027 therm. Which is TOTALLY wrong. I should have checked it, but I didn't think they would have gotten a simple conversion unit wrong, and math and measurements are NOT my forte, so I didn't know that it looked totally wrong. I looked into everything when John mentioned that the amount of therms seemed way high. Well, you were right John. So I figured fuck that website(which I trusted because they DID have a legit source, they just did calculations and conversions wrong) and I decided to figure out the numbers for Montana instead, since that is where this thread originated anyways.

SO, here are my new and improved numbers.

There are on average 20,819 MMcf (millions cubic feet) delivered to residential homes in Montana annually.
source

There were 358,667 homes in Montana in 2000.
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60% of those homes in Montana use natural gas.
source

So, that would mean that the average house in Montana which uses natural gas uses 96,742.47 cubic feet of it. (60% of 358,667 is 215,200.2 and so 20,819,000,000/215,200.2 = 96,742.47 cubic feet.)

So, 96,742.47 cubic feet to therms is 1,000.433 because to produce 1 therm of energy, you need to use about 96.7 cubic feet of natural gas.

So, the average carbon dioxide coefficient of natural gas is 0.0544 kg CO2 per cubic foot (source). So, 96,742.47 cubic feet of natural gas emits about 5,262.76 kg of CO2, and because there are 1,000 kg in a metric ton, that equals 5.26 tons of CO2 emitted a year for a montana house using natural gas to heat.

Again, I am seriously SO sorry I screwed this up and made this giant claim that is totally fucking wrong, but I hope this fixes things. :/ Please check my math and let me know if this still has issues.

Cassie,

I'm not sure I'm following your math or not. I haven't done any for way long either.

You are saying you made a ten fold error in CO2 (5ish/55ish tons) but underestimated by half the volume of natural gas used (43,000/96,000 cubic feet)?

Landon Sunrich wrote:Cassie,

I'm not sure I'm following your math or not. I haven't done any for way long either.

You are saying you made a ten fold error in CO2 (5ish/55ish tons) but underestimated by half the volume of natural gas used (43,000/96,000 cubic feet)?

The ten fold error was just due to that website telling me that 1.027 therm=1 cubic foot.


Yes, I had used the 43,000 number because I just got it off this website which I trusted, because they were using this site as a source and it looked legit to me. BUT when I went to actually look at the numbers on that EPA data,
I couldn't figure out where they got the 43,000 number, so I decided to just find my own data on montana, since that was what the original post in this thread was about. So my own research
and calculations got me the 96,000 number.

There are only 300,000 homes in Montana? Sheesh. Montana could fit in one building.

Except I'm not sure they'd all get along with Paul.

So how many cars does this mean you "take off the road" by switching from natural gas to a Rocket Mass Heater?

I think the 96000 number is more important. I mean that's cubic feet of fracked earth right? How much timber is grown in commercial forestry operations? like, in 96,000 square feed (cause cubic wouldn't make sense here.) I mean if you can grow say... 2 chords of wood or more in 96,000 square feet then just based on land use....

You see where I'm trying to take this thought?

well I feel dumb too, because it doesn't make sense that one fuel would be so much different from all the others.
And natural gas if anything has more hydrogen per carbon - its exhaust is pretty wet - so for it to be ten times worse for carbon dioxide ... yeah, now that you mention it, that seems weird.

This graph Paul already found seems more plausible, but doesn't necessarily get us into the depth we'd need to compare a single RMH in a single house.

paul wheaton wrote:

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With trees per hectare - it's hard to match the density of fossil fuels, generally.
The problem as I see it is we're trying to play apples to apples, and the big picture says:

growing trees faster than you burn them is generally speaking compatible with life on earth as we know it.
extracting a bunch of carbon-rich minerals that last saw sunlight in the Cretaceous is de-stabilizing life as we know it.... and the result, after the party is over, is likely to be an impoverished life in which we will have to adapt to increasingly hostile environments, and/or to hostile people who have lost their place and livelihood.
it's very hard to stop because these carbon-rich minerals by their very concentration allow us to do things with personal ease and safety that our pre-industrial ancestors could only dream about, like fly, and go to the moon, and cross seven leagues in less time than it takes to eat lunch, if not quite in a single step. And we can do all these things largely by using fire, one of our all-time favorite tools as a species.

So all these accounts that leave out the "before" part of the picture - how that energy gets there - those accounts are making fossil fuels look lily-white.

If the wood you are using would otherwise be thrown in a burn pile, or composted, then the emissions due to the wood stove are neutral - they would have happened anyway, perhaps slower, perhaps faster.
If you are cutting trees to fuel the heater, you've neutralized those trees' ability to absorb any further carbon. If you're cutting timber older than your stove, instead of coppicing or pruning or harvesting deadfall, you are probably doing more harm than good.
If the biodiesel you burn is coming from used fryer oil that would otherwise have been thrown away, you are not quite carbon neutral but you're relatively guilt-free.
If the biodiesel you burn is coming from cutting down vast swaths of ancient rain forest to grow oil palm, you are part of the problem.

And how do we measure the cost of contaminated groundwater and aquifers from mining, frakking, etc?
These are not carbon output - they are other pollution - but if they result in populations having to move, or transport their water over longer distances, or use more electricity to pump from a deeper well, that's a hidden impact too.

And the cost to get propane to a place up at 5000 feet in the mountains is going to be different from in a city where you can walk to a depot, and with distance from the sources.

I think there's a reason these numbers are hard to get. They are hard to measure.

-Erica

And how do we measure the cost of contaminated groundwater and aquifers from mining, frakking, etc?
These are not carbon output - they are other pollution - but if they result in populations having to move, or transport their water over longer distances, or use more electricity to pump from a deeper well, that's a hidden impact too.

That is a great point. A few other considerations that come up are earth quakes being caused by franking operations, salt water and deisel fuel being shot into shale layers at high pressure. There is still so many areas that have not been completely degraded from oil and gas operations, but as the methods get more expensive, more complicated, and less efficient at extraction, the destructiveness goes up and up rapidly.

Carbon is like the celebrity of greenhouse gases, even though it's difficult to calculate it is easier to calculate than the other gases. So methane is actually a very bad gas in the environment and in the industries methane has more carbon units attached to it, meaning it is more potent than other pollutants.

Montana contains what is called coal bed methane, which can be sold and used similarly to natural gas. The idea is the methane is sealed into an aquifer, so they go in and get it. ( guess what happens to the water)

Here is a webpage talking about this stuff in Montana. Check the credits at the top of the page. Is John Wheaton in the family? Lol

I'm realizing more and more there's a balance between a) getting the numbers (really valuable if you can do it, but at some point you can't know everything and b) going with what seems commonsense and just focusing on that solution.

I don't need to look at numbers to see that coppicing is more sustainable than cuttind down the whole tree and starting from scratch. That's pretty clear from direct sensory evidence. And I'm told it extends the life of the tree, also seems like something that agrees with common knowledge and that I can test with my own experience (at least on shorter-lived plants, pruning them does seem to help them in some cases). Even if it doesn't, I guess cutting down the whole tree clearly doesn't extend the life of the tree, so there we are. Also, it's pretty easy to coppice, relative to cutting the whole tree down. Low investment, big potential returns.

As for choosing wood over extracted, non-renewable resource, it also seems commonsense.

Maybe I'm being biased. I want to think coppicing and wood burning will be the better solution because they're more "natural." However, it's the best I can see from the data I have. It makes sense for me to just tke action I can take based on that at this point and delay reassessing for a period of, say, 5 years. At the moment, there doesn't appear to be a lot I can do to transition to wood-burning in my situation, but I am involved in advising on a new construction project and can make the information I have available in that conversation.

Lastly, it's *kind of* apples-to-apples comparision if you say "I took one car off the road" with "I took one house off the gas grid" since the transportation, extraction, and so on, of the fossil fuels ought to be roughly the same. Also, both are non-renewables without a really long time-span (millions of years) vs. the wood which is a few years.

Now that I think of it, as fun as this figure would be to have, it's probably not the most important figure. Maybe we just need to know what percentage closer it gets an individual to being in the black ecologically?

Hey - carbon from trees is way different from carbon from petro and coal that has been locked up for a really long time. Therefore it really isn't the same animal at all, if one even wants to pretend that man made CO2 is really the cause of climate change.
Personally i think it's imperative to get rid of the bad energy systems now extant, but for a multiplicity of reasons, and carbon isn't high on the priority list. There, but nowhere near the top.
Did any of this calculation figure in the energy costs (in carbon if that is your measurement) needed to drill, refine, transport the gas/diesel, etc? You could go back to the energy necessary to make the huge amount of refinery infrastructure, tools, etc. Chainsaw is a tad less than a refinery and trucking/tank farm set up, lol.

Personally i'm more worried about the petro runoff killing our plankton/cyanobacteria and it's having reduced more than one-third of our poor planet's oxygen production - yup - to now get your #35 oxygen each day you now have to work 50% harder. Hmmm. Not good. Plus virtually every petro is an endocrine disruptor - which damages in a non-monotonic and non-linear manner at levels in the parts per BILLION - frequently MORE at the lower ranges than in the higher many parts per million, believe it or not. There is science on this, and nothing says we have to treat everything like Paracelsus concluded prior to 1543, lol.

Joshua, I agree as far as seeing what is common sense And choosing wood over coal. Whenever people respond to an argument for wood burning stoves they always talk about where everyone will get the wood, can the forests support that many people etc.. It seems to coppice and use of rmh is most efficient for a wood burning heating system, it will minimize waste and minimize imports into the system. If you managed your coppices well and had enough, you would have perpetual firewood.

Joshua Myrvaagnes wrote:

Lastly, it's *kind of* apples-to-apples comparision if you say "I took one car off the road" with "I took one house off the gas grid" since the transportation, extraction, and so on, of the fossil fuels ought to be roughly the same. Also, both are non-renewables without a really long time-span (millions of years) vs. the wood which is a few years.

It is kind of Apple to Apple, but I think there are some orders of magnitudes in the difference there. According to the epa list of carbon sources Residential emissions make up 10 percent of the total while transportation makes up 28 percent.
With this distribution, hypothetically if every house and business reduced its carbon footprint to near 0, there would still only be a 10 percent decrease in co2 emissions overall.

Based on the percentages I think it is more apples to apples to say 1 Or a few cars off the road is similar to 1 house off the electricity grid.

Something that would improve emissions in the biggest way would be a solution for people in the transportation and electricity areas, since those are the areas in which the most waste is coming about.