carbon footprint and heat

In preparing for a presentation I gave last week, I worked out the following bits and bobs:

the average american car puts 4 tons of CO2 into the air per year.

the average montana house heated with natural gas puts 8.9 tons of CO2 into the air per year  (2.2 cars)

the average montana house heated with electricity puts 29.4 tons of CO2 into the air per year (7.4 cars)

the average montana house heated with a conventional wood stove puts 4.4 tons of CO2 into the air per year (1.1 cars)

the average montana house heated with a rocket mass heater puts 0.4 tons of CO2 into the air per year (0.1 cars)

So the average woodstove puts less than 1 ton into the atmosphere... Yet wood stoves seem far more regulated than natural gas.

Kyrt Ryder wrote:So the average woodstove puts less than 1 ton into the atmosphere... Yet wood stoves seem far more regulated than natural gas.

The woodstove industry doesn't have the lobbyi$ts that the natural gas industry has, is my guess...

I updated the top post a bit and converted it to a wiki.

Just to add complications I was thinking of my grandmothers house in the 1960 had coal fires in most rooms but heated the bathroom via a special light bulb . Sold specifically for that purpose .
She often bought sea coal- this was coal picked off the beach dried and sold cheap to those in the know I doubt she would fit in these graphs and charts

David

Landon Sunrich wrote:What does a ton of wood look like? In chords?

It is about half a cord.

1 cord, as defined by pile of wood, 4 feet wide by 4 feet high, and 8 feet long, made out of commonly found hardwood, weighs 5400 pounds green. Softwood is about 4500 pounds per cord green.

paul wheaton wrote:In preparing for a presentation I gave last week, I worked out the following bits and bobs:

the average american car puts 4 tons of CO2 into the air per year.

the average montana house heated with natural gas puts 8.9 tons of CO2 into the air per year  (2.2 cars)

the average montana house heated with electricity puts 29.4 tons of CO2 into the air per year (7.4 cars)

the average montana house heated with a conventional wood stove puts 4.4 tons of CO2 into the air per year (1.1 cars)

the average montana house heated with a rocket mass heater puts 0.4 tons of CO2 into the air per year (0.1 cars)

Hi Paul,

This jives with the calcs I did on https://cruxhomes.com/environmental-impact/

Perhaps yours is newer, but I've got slightly different data:

Estimated Equivalent Metric Tons of CO2 Per Passenger Vehicle Per Year 4.67 (5.15 tons)

It's the third item on:

18 - U.S. Environmental Protection Agency – Greenhouse Gases Equivalencies Calculator – Calculations and References:
https://www.epa.gov/energy/greenhouse-gases-equivalencies-calculator-calculations-and-references

If you want to include some national average data in your calculations, please feel to use what I've done on the environmental impact page.  I listed all my references on https://cruxhomes.com/links/, but I'll put the relevant ones here for your convenience:

17 - U.S. Energy Information Administration – Household Site End-Use Consumption in the U.S., Totals and Averages, 2009:
https://www.eia.gov/consumption/residential/data/2009/c&e/ce3.1.xlsx

19 - U.S. Census Bureau – New Privately Owned Housing Units Started in the United States by Purpose and Design:
https://www.census.gov/construction/nrc/pdf/quarterly_starts_completions.pdf

If there is anything I can do to help you out, please let me know . . .

Cheers,
CJ

Last week Paul sent me this link:

https://www.eia.gov/todayinenergy/detail.php?id=37433

My mind was blown. Not because it was brand new information that was totally different than any I had seen before... but because of some very interesting side observations that I made from the pretty charts.

First up, household energy consumption distribution:



A good reminder that solving space heating is far more important than "better" lights or reducing phantom loads. Actually, I'm surprised that lighting is so high. I suppose it's because of all the people who keep lights on even when they are not in the room.

Something that I just noticed is that wood is not listed as a fuel source on this chart. And since there are a number of people who (at least partially) heat with wood, the space heating slice of the pie should probably be even bigger than it is here.

---

Next up, energy consumption by number of household members:



I think that this chart shows quite powerfully the energy impact that community living can have.

Looking at the chart, it looks like it's 38 million BTUs to heat a household of 6 and 30 million BTUs to heat a household of 1. So for heating a household of 1 uses 30 million BTUs per person and a household of 6 only uses just over 6 million BTUs per person. That's a 5X savings!

Ditto with AC.

For water heating at first I thought it was less efficient. But when you do the per person calculation it is also more efficient.

---

I found this last one a bit confusing:



It's showing the distribution of the amount people are paying on their bills for these different categories and fuel sources.

When I looked at this chart one thing burned clear in my mind. And I kept wondering if I was reading the chart wrong. But I've looked at it a few more times and it's still there. Here's what I see:

Americans who don't heat with wood collectively spend 60 billion dollars on heating their homes every year! Is there a market for rocket mass heaters in the US? Yes. Yes there is. A 60 billion dollar market!

Thanks Shawn.

There is a distinction between "more efficient" and "in the black ecologically," and this is something the Better World Book is really helping me grasp.  Much of the other solutions we're used to see around in the US are "how to make things less bad"--sometimes significantly less bad!--and that's not nothing, but it's still not a real solution in a sense.  It's not your "final answer."  

Putting more people in one house, in the cold climate, could be a part of the final answer, however.

Or, putting more sun into the thermal battery of the passive solar house.

Certainly, sharing a hot water supply makes really good sense, not just for "less bad" but for "in the black."




Another thing I take from this is "natural gas is cheaper, moneywise, even if it is not cheaper carbon-wise, and this is distorting people's perceptions of the real cost of heating up space"
-----

I also wish we had a chart to show how the consumption works for a household that is in the black carbon-wise.  It should be more pronounced--more people = more 100-watt heaters in the house = less wood needs to be burned.  The charts above barely reflect that, but in "developing" countries and in truly sustainable homes in "developed" countries the more people the more heat, period.  

A chart of what's truly sustainable would make it more real in people's minds too, I think.  Anyone with chart-making skills and some numbers want to take a crack at making one?  

Landon Sunrich wrote:What does a ton of wood look like? In chords?

A cord (128 cubic feet) of mixed hardwood green weighs 5200 pounds.

That would make a pile four feet high, four feet wide, and eight feet long, or (3) piles of 16 inch wood, four feet high, eight feet long.

Shawn Klassen-Koop wrote:L
When I looked at this chart one thing burned clear in my mind. And I kept wondering if I was reading the chart wrong. But I've looked at it a few more times and it's still there. Here's what I see:

Americans who don't heat with wood collectively spend 60 billion dollars on heating their homes every year! Is there a market for rocket mass heaters in the US? Yes. Yes there is. A 60 billion dollar market!

Not necessarily. How many of those potential houses are controlled by lending institutions that require insurance? Insurance companies may not be able to directly stop a home from being heated by "solid fuel appliances", but the rates homeowners pay for those appliances can be prohibitive enough so that they stay with "traditional" sources of heat like propane, oil, electric, etc.

I cut a lot of wood, and sell a lot of firewood, but I do not sell nearly as much as I used to; no one does. Pellets have really hit the firewood industry hard, and for good reason. It comes in convieniet 40 pound bags, burns hot, has consistency, and stoves have tight clearances to walls so homes can have more room for living instead of open space for an old woodstove.

But there are other factors too; subtle ones. Like the average American family having very little time. They do not want to deal with firewood in any sort of way. They do not have time, even people on here have made this mindset clear; "just work overtime at work and buy the things you need." That includes propane, electricity or gas that is automatically administered into the house as they are away. If you don't think this is significant, consider that this Thanksgiving, I will be home, tending to my woodstove while my family is at the inlaws. Someone has to keep the house from freezing up the pipes, which is NOT something homeowners with tradional heat have to deal with.

Add in even more drama like the smoking dragons of those dreaded outdoor wood boilers that create local smoke ordinances, and broken families that lack the time to gather and process wood because they are on the road traveling to and from ex-spouses homes, and it all ends up to a grim picture for the fate of firewood no matter how it is burned.

I am not saying I dislike Rocket Stoves, I am just being realistic, because when you boil down the dross to only the people who own their home and can dictate their own heat source, have enough money to pay for the increased insurance premiums, live in a community where smoke ordinances are not an issues, have enough time in the family to gather and process firewood, want to work with an inconsistent output of heat, have a higher risk of causing destruction to their home and belongings by potential fire, have the added space in their home; well...it gets drastically whittled down from a 60 billion dollar market.

One really hard thing to calculate here is what people use for heating sources. I would NEVER depend upon a single source of heat, and in Maine I do not know of too many that do. heating our homes is tough business here!

My father has wood, coal, corn, or #2 furnace oil (here on out called oil: a very common heat source in the Northeast)

My Tiny House has Oil, Firewood, Coal, Corn and Pellets

My other house has Firewood, Coal and Propane

My house in New Hampshire has Firewood and Oil


Sadly, when the US Government does their surveys they only ask for "Primary" sources of heat. This unto itself is misleading, but for someone like me or my father, we burn whatever is cheaper at the time. Generally it is firewood in the shoulder seasons like Fall and Spring, then when it gets really cold, switch to coal to really crank out the BTU's from the stove. In other words I draw from a variety of fuel sources to get me through the winter depending on what best suits my needs in terms of output, control, and cost.

Some are merely back up, like burning corn. Having the ABILITY too burn it, just means if pellets were short for instance, I would just burn that in a pinch if I had no firewood/coal/propane/oil/etc.

This is good food for thought.

On the "keeping pipes from freezing" thing, it makes the idea of thermal inertia and rethinking plumbing more essential.

After the explosions in Lawrence, MA, I speculate there are lots of people who are quitting natural gas.  Whether the threat is real or not, the perception of possible explosion is a deterrent.  I read a quote in an article of kids saying they were afraid of gas, and if my memory serves the parent said, Wow, I have to agree, that does seem really dangerous.

Is it a matter of paying really high premiums for the insurance more than just 'we won't insure that"?  if so, what amounts are we talking here? maybe you come out ahead?  

Travis Johnson wrote:One really hard thing to calculate here is what people use for heating sources. I would NEVER depend upon a single source of heat, and in Maine I do not know of too many that do. heating our homes is tough business here!

My father has wood, coal, corn, or #2 furnace oil (here on out called oil: a very common heat source in the Northeast)

My Tiny House has Oil, Firewood, Coal, Corn and Pellets

My other house has Firewood, Coal and Propane

My house in New Hampshire has Firewood and Oil


Sadly, when the US Government does their surveys they only ask for "Primary" sources of heat. This unto itself is misleading, but for someone like me or my father, we burn whatever is cheaper at the time. Generally it is firewood in the shoulder seasons like Fall and Spring, then when it gets really cold, switch to coal to really crank out the BTU's from the stove. In other words I draw from a variety of fuel sources to get me through the winter depending on what best suits my needs in terms of output, control, and cost.

Some are merely back up, like burning corn. Having the ABILITY too burn it, just means if pellets were short for instance, I would just burn that in a pinch if I had no firewood/coal/propane/oil/etc.

Joshua Myrvaagnes wrote:This is good food for thought.

On the "keeping pipes from freezing" thing, it makes the idea of thermal inertia and rethinking plumbing more essential.

Joshua, for some reason my spell check is not working, so if I have a ton of mispelled words, it is only because I did not catch them in proof reading this reply.

That being said, I think you are absolutely right and that thermal inertia is the answer, and I think I figured out the best way to do that. In my old house, which had radiant floor heating with domestic water run through the concrete slab...and a ranch style house, I achieved thermal inertia with 400 tons of rock laid down prior to the pouring of the slab. This made my "radiator" esentially 3000 square feet and several feet thick. Because ground temperature here is 57 degrees, I had an incredible heat sink to draw from. In fact when outside air got down to 18 degrees, my home was 48 degrees inside. This is amazing because no one lives there, it is currently vacant. No people, no contents, no heat from appliances, nothing. In fact, if I turned on my circulating pumps, and just ran the pumps with no boiler running, I think I could keep my super insulated home from freezing all winter. That is because I am pumping 57 degree water to the outside of my slab where ambient temperature affects it. BUT it is a very small percentage of my slab that is affected. Averaged out, it would remain above freezing.


Unfortunately, the human body is not designed for 48 degree temps, nor 57 degrees. For my house, I went with limited glazing and super insulated walls and ceiling, BUT I think there is an alternative that few people talk about. If passive solar causes glazing that is low in R-factors, active solar might be the answer. In this way I could build a solar collector seperate from my home, and then draw that warmth into my home via controls and ducting. When it was working, I use it, and when not, I do not. In between, my super-insulated home is just that, insulated from the cold.


Another idea is to use Jean Pain's compost heaps to draw heat into the home.

Now in contrast, my other home across the road has a fieldstone foundation. It essentially acts like a sump amd allows cold air down into it. Today was 20 degrees out and as I type this it is 62 degrees in here with a pellet stove running upstairs, and now (because I hate to be cold) my coal stuff chugging out the BTU's burning coal in the basement. I had to, it was 38 degrees down there this morning! (It is 70 degrees in the basement with the coal stuff going)

So with two very contrasting houses, I think I figured out thermal inertia, at least here in Maine. That is, concrete slab on grade, with extra thermal mass under it, radiant heat in the slab, with of course, the domestic water pipes embedded in the concrete as well. And the house itself has to be a ranch to benefit from that slab on grade.

As for the other house, the one I live in now (my Tiny House). I am thinking about building active solar and then pumping the collected heat into the basement to keep my pipes from freezing without having to run a seperate stove. It would just keep me from having to fuss with two stoves constantly.

In the last couple of weeks I have read a lot about natural gas home heat has a problem with a lot of leaks.  The leaks put methane into our atmosphere.  And methane is a worse greenhouse gas - possibly by a factor of hundreds.

I wonder what the math is for natural gas as it relates to this thread?

In the first post it says

the average montana house heated with natural gas puts 8.9 tons of CO2 into the air per year  (2.2 cars)

Does that need to suggest something like "37 tons*" followed by "* = adjusted to convert methane leaks to CO2 equivalents"?

(note that I just made up "37" - I am hoping that somebody will math this out)

Calculations of the CO2 equivalence of methane are a factor of 28 to 34:

Global Methane Emissions

Calculations of methane leaks from U.S. household appliances are 0.038% of total gas consumed, accounting for 0.1% of U.S. anthropogenic methane emission:

Unburned Methane Emissions

Edit: The equivalence numbers above are the "long term" equivalence, i.e., the effect over many decades. Estimates for short-term time spans (one or two decades) can go as high as 80x.

I thought recent reports showed that natural gas leaks are currently in the 2 to 3% range which is far higher than previously estimated.  And some of the rough math was saying that the effect of this made co2 equivalent footprint about three or four times higher than the co2 footprint.

If we say that methane is 30 times worse than co2, and if the montana home thing is 8.9 tons of co2 ...  

So if that home received 100 units of natural gas which generated 8.9 tons of co2 ....  and 2% of that leaked on the way, but was 30 times more impactful, then that add 60%.  

So my quickie math says that if the co2 is 8.9 tons, then the co2 equivalent is 14.2 tons.

Indeed, NG leakage across the entire supply chain -- especially at the point of production -- dwarfs the point-of-use leakage at the consumer end. So, assigning a 2% leakage for household use seems reasonable when the "embedded" supply-chain loss is included.

One reference to a revised estimate of 2.3% gross leakage (compared to the older EPA estimate of 1.5%) comes from a 2015 study. The final sentence of the quote appears to suggest that the short-term climate forcing produced by the leakage is equivalent to doubling the amount of CO2 produced by combustion of the product:

Assessment of methane emissions from the U.S. oil and gas supply chain

Methane emissions from the U.S. oil and natural gas supply chain were estimated by using ground-based, facility-scale measurements and validated with aircraft observations in areas accounting for ~30% of U.S. gas production. When scaled up nationally, our facility-based estimate of 2015 supply chain emissions is 13 ± 2 teragrams per year, equivalent to 2.3% of gross U.S. gas production. This value is ~60% higher than the U.S. Environmental Protection Agency inventory estimate, likely because existing inventory methods miss emissions released during abnormal operating conditions. Methane emissions of this magnitude, per unit of natural gas consumed, produce radiative forcing over a 20-year time horizon comparable to the CO2 from natural gas combustion.

A more recent study estimates a gross leakage of 9.4% (note that the numbers are for a single gas field, not for all U.S. production):

Quantifying Regional Methane Emissions in the New Mexico Permian Basin

We estimate total O&G methane emissions in this area at 194 (+72/–68, 95% CI) metric tonnes per hour (t/h), or 9.4% (+3.5%/–3.3%) of gross gas production.

The U.S. Environmental Protection Agency (EPA) Greenhouse Gas Inventory (GHGI) estimates a national NG production loss rate of 1.5%, but the GHGI has been identified as a conservative estimate of methane emissions, and a recent alternative estimate finds a U.S. national average NG production loss rate of 2.3% based on a synthesis of measurements from across the O&G supply chain. Note that the Permian findings are even higher than this adjusted national average. One possible driver of larger emissions in the Permian might be the large point sources found by Cusworth et al.: infrequent large emissions (so-called “super-emitters”) are thought to play an important role in driving total emissions. Across many studies, the top 5% of sources contribute over 50% of emissions.

2.3%


And, more recently (possibly just the one site)


9.4%


Until more data comes in, do you think it would be fair to suggest 4%.  Specifically, I think I am going to suggest 4% for now - and later I will certainly be proved wrong, only I think there is a 50/50 chance that the number will be higher.

My question is:  do you think ME selecting 4% is fair?   My plan is to do the asterisk thing.  Perhaps you would stick to the 2.3%.  Or perhaps you would choose another number as "probable" considering the 9.4%?

I personally would use the 2.3% value for the following reasons:

1) The 2015 study, although based upon older data, specifically produces an estimated average for the entire U.S. supply chain, which is what I'd want for estimating an average embedded cost.
2) The 2022 study, although based upon more recent data, represents a single-point value rather than a national average.
3) The 2022 study notes that 50% of the observed anomalous leakage comes from just 5% of the wells ("super emitters"). It's conceivable that similar anomalies exist in all U.S. gas fields (maybe those wells were drilled by "Almost Honest Earl's Drilling Inc.?) but, lacking confirmation, I wouldn't assume the single point represents a national average.

In the introduction section of a publication I might place a caveat on the 2.3% value, noting that a recent study found 9.4% in a portion of the Permian Basin, but I wouldn't produce any calculations using that value. The conclusions produced by using the conservative 2.3% number should be impressive enough. And in future, if the 9.4% number proves to be the norm, that's a whole 'nother paper almost for free!

Hmmm .... from last month ...   https://www.nature.com/articles/s41467-022-29709-3

... suggesting that methane contributes 80x to greenhouse gases compared to co2 ....  

I got to this document through a rabbit trail that seemed to suggest much higher leak values.  But after ten minutes, I am struggling the fish out the results ...

The choice of a number for CO2 equivalence seems to depend on what time scale you're looking at. Apparently, if you're trying to analyse methane contribution to near-future warming, you use a 20-year potential; if you're considering the long haul, you use a 100-year potential. Due to the time-integral used in calculation and the short lifespan of methane in the atmoshere compared to CO2, the relative contribution of methane diminishes over time.

CO2 equivalence over the next 20 years, "GWP20" = 84
CO2 equivalence over the next 100 years, "GWP100" = 25

Short- and long-term warming effects of methane may affect the cost-effectiveness of mitigation policies and benefits of low-meat diets

Non-CO2 GHG emissions are commonly reported as ‘CO2-equivalents’ (CO2e) and calculated using the 100 yr global warming potential (GWP100).
NDCs in which nations set out their emission reduction targets (...) are largely built on this approach. As a metric that provides a single per-emission weighting of each gas, the GWP100 fails to capture how the relative impacts of different gases change over time. Due to its short atmospheric lifetime, the impacts of CH4 emissions rapidly decline after a few decades. Meanwhile, due to its long lifetime, each CO2 emission exerts a relatively stable impact on global temperature into the long term. The relative valuation of CH4 to CO2 is thus highly sensitive to the metric used, particularly the metric’s time horizon.

Excellent point!

I can see why you chose "30".

For people who prefer auditory input to reading or who just love the dulcet tones of Paul, he and Alan talk about some of the points in this thread in the latest podcasts - podcast 641 and podcast 642.