carbon budget « Eat Close To Home

Propane mystery and comparison of heating fuel saving measures

April 29, 2011 at 7:10 pm (carbon budget, Energy, green living)

As I’ve been doing the last few years, I tracked our propane usage this year. It was a rather nasty surprise. We used more this year than last year, despite getting some new windows, a new patio door, and switching from heating the living room to only heating the “library” a couple times a week.

Here are the data. BTW, a “heating degree day” is the unit they use to talk about how cold the weather actually is. (Look them up on the Almanac feature of Weather Underground.) I calculate usage on a gallons-per-heating-degree-day basis to control for variations in the weather.

	Gallons of propane	Heating degree days	Gallons per heating degree day	Thermo- stat (away or asleep/ home and awake)	Improve- ments in effect this year	Comfort
2004-05	892	6126	0.1456	60/66	Programmable thermostat; window plastic
2005-06	719	5545	0.1297	60/66	Turned heat up when getting home instead of programming; window plastic
2006-07	818	6715	0.1218	55/66	Attic insulation; inflatable flue blocker; no window plastic
2007-08	844	5771	0.1462	55/66	Window plastic
2008-09	690	6993	0.0987	55/63	Fireplace insert; used on weekends	Warmer than last year despite lower thermostat setting
2009-10	395	6562	0.0602	55/62	Using fireplace more evenings; wall insulation; window plastic	Need to heat whole house every few days or 55 is too cold at night
2010-11	470	6893	0.0682	55/60	New windows and patio door; no window plastic; evenings in library	Sometimes chilly; bedrooms warmer – 55 is fine.

The drop between ’04-’05 and ’05-’06 came from turning the heat up manually when we got home, instead of having the programmable thermostat turn it on at the same time every night. See, we have activities a couple nights a week that kept us out of the house until 8 or so…so all that heat was wasted from 5-8pm.

The big drop between ’07-’08 and ’08-’09 came from installing and beginning to use our fireplace insert. Not only did it provide heat, it also stopped the biggest draft in the house: the unused chimney. We used it even more in ’09-’10. Notice that we felt warmer with the thermostat set 3 degrees cooler. I think some of that change was also the attic insulation. We didn’t see any savings the year after we put the insulation in because we were leaking propane at the tank. I have no idea how much was wasted that year even before we could use it.

In ’10-’11, we replaced some fairly draft 10 y.o. vinyl double-pane windows with Andersens (bedroom, “library,” and kitchen patio door). I still felt a breeze on my head in bed, though my nose was no longer cold all night. I think the breeze was convection, not infiltration. We also repurposed the spare bedroom into a “library” with a futon. We would heat that with an electric space heater several nights a week instead of stoking up the fireplace. Comfort-wise, that heat was not as satisfying as a fire. We also had an incident where a loose wire overheated and melted and could have caused an electrical fire if we’d not caught it. The electrician said this was because the space heater was drawing more load than the circuit was really rated for.

Despite all those measures taken this year, we used 75 more gallons of propane this year than last. The winter was colder, but if we had used propane at the same rate as last year, we would have only burned about 415 gallons this year. So why did we end up burning 55 more gallons of propane?

Here are my theories. I would love to have the input from all you smart people out there.

The fireplace and the thermostat are both in the living room. Last year, when we’d heat with wood, the living room temp would go up from the time we got home until well after we went to bed – meaning the furnace didn’t run at all for at least six hours each day. This year, when we would heat only the library, the thermostat still thought the whole house was cold, and so the furnace came on more frequently.
We didn’t put up any window plastic this year. The large picture windows in the living room could have lost a lot of heat. We also didn’t seal the patio door shut this year, so we would occasionally open that door to take out the compost or go to the greenhouse, which lets outside air directly into the kitchen.
There’s a leak at the propane tank, or someone stole propane, probably during October.
The tank was filled in July ’10. The decrease in volume between July and October was due to temperatures, not actual propane use, so the reading suggesting we used 20 more gallons of propane between May and October this year compared to last is spurious. (That still leaves 35 gallons to account for.)
The pattern of when it was cold is as important as how cold it was. We had a much colder Nov/Dec this year as compared to last…but supposedly, from May-Oct it there were far fewer heating degree days this year (803 vs. 1130).
There’s some weird thermodynamic benefit to really heating the house thoroughly once a day. (This sounds like hokum to me.)
It was much less sunny this year and we got less solar gain, especially in the living room.

What seems most plausible to you? Got any other ideas?

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State of the Homestead: Energy

June 16, 2010 at 2:07 pm (carbon budget, Energy, green living, Musings)

Part of the State of the Homestead series

Energy. We just about hit our carbon goal of 10.45 tonnes last year (actual: 10.53t).

Heating was our biggest success, I think. We used about 400 gallons of propane last winter, compared to nearly 700 gallons the year before and 850 gallons in 2008.We used the fireplace as our primary heat for the living room, whenever we were going to be home for more than 3 hours. The thermostat on the furnace was set at 55 most of the time, and we found that it’s a pretty comfortable temp for us to sleep in. Spring and fall, when it was 60 overnight, I was kicking off covers, tossing and turning, and sweating half to death. When we did use the furnace to make the whole house warm, we found that 62 or 63 was pretty comfortable. I attribute that to insulating the walls last summer, getting the window plastic up early, and acclimating to a cooler house.
We can get our electricity usage under 300kwh/month in the summer. This requires that we turn off the radon fan, which uses almost 100kwh/month. I figure, all the windows are open in the summer, so the radon isn’t accumulating. We do turn it back on any time the windows will be closed for more than a couple days. The other big energy user is the furnace and a/c fan. Last year, the weather was such that we didn’t turn on the a/c at all. Hopefully, we can do that again this year. This is still well above the recommended 3kwh/day, but with the stove, dryer, and water heater all electric, I’m not sure how to cut more.
Gasoline. This is a hard one to cut down on. We drove quite a bit less this year, not necessarily by choosing to not do things that required driving, but because those activities didn’t present themselves. (For example, Scott no longer needs to drive to Missouri three times a year for his retreat series.) Driving any less than we do now would mean cutting trips to see family.
Air travel. Still flying a lot; it’s hard not to, what with the family spread all over the country. Trains are not at all practical for the places we need to go, and when I do the math, they don’t actually save all that much, anyway. I don’t know that there is a good answer for this one. This coming year has a wedding, a new baby, local friends moving across country, and our 10th wedding anniversary, too. *sigh*
Alternative energy: We are to a point where we can get through multi-hour power failures with little fuss. We have several options for light, heat, and cooking facilities. We can heat water on the fireplace and keep it warm overnight to have enough warm water for a quick wash, if we want. We’d still like a way to charge phones and possibly run a fan, so we’re exploring options for solar battery charging. I think we lost power for over an hour four or five times last year; it’s nice to feel like we can continue an evening as usual without worrying about water, light, etc.

We’re at the point where I don’t know what we can cut any more. The low-hanging fruit is gone. Cutting more energy moves us into the “drastic lifestyle adjustment” area, which is tough. We live 11 miles from work, and though we’ve talked about moving closer to town, the fact is, we really like this house and this land. We also don’t feel like going through the process of selling a house, packing, and moving. We already drive to work together, combine trips, and all that. I don’t know how much more we can cut down on our driving without becoming hermits. Geothermal is an iffy proposition in Michigan, from what I can tell, and very, very expensive. Air travel I mentioned. Our food is already pretty darn local. Solar hot water? Maybe. If you have any suggestions, please let me know!

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Propane savings to date

January 13, 2010 at 5:05 pm (carbon budget, Changing habits, Energy, green living)

Well, we just got our first propane fill-up of 2010. Usually by Jan. 12th, we would have had fillups totaling around 500 gallons. This year, we’ve had a total of 371 gallons – about a 25% reduction in propane use and a savings of $325 and 1625 pounds of carbon.

What we’ve done differently this year: We’ve kept the heat at 55 pretty much all the time and used wood to heat the living room evenings and weekends. We do still occasionally turn the furnace on to heat the whole house – maybe once or twice a week when it’s really cold and we’re only going to be here for two hours or something.

We also have the thermostat programmed to come on and raise the house temp one degree in the morning while we’re working out. Having the heat on makes it feel warmer, and we’ve learned that just getting the heat to kick on is sufficient to keep us warm in the mornings – it doesn’t need to come up to “normal” room temp. Keeping it to one degree also helps me not have nightmares in the early mornings, which beset me when I’m too warm while I sleep.

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Greatest good

November 5, 2009 at 11:29 am (carbon budget, Energy, Food security, green living)

global warming I realized the other day that the next realistic steps my household might take to reduce carbon emissions are to carpool more (we commute to work together but could add up to 2 more people in our car) and to move to geothermal heat.

Geothermal systems – even with the rebates – would probably cost $15,000. That’s a ton of money. Even supposing we had $15K to spend on a system (and that’s a big “if”), would it be the best way to spend it? What would truly be the most carbon-reduction-bang for fifteen thousand bucks?

Some initial ideas:

Help 15 households insulate their attics to R-60
Buy super-efficient furnaces for several households
Help 3-5 farmers build hoophouses to produce local veggies through the winter
Invest in a “neighborhood energy startup” with a gasifier (makes heat and electricity and biodiesel), possibly with a permaculture system of greenhouses, coppice groves, etc.
Just buy land and start a coppice grove for sustainable heating fuel production, and possibly invest in a pelletizer
Some kind of education program? I’m thinking the actual return is hard to measure, and it’s not education about global warming that folks around here lack.

Anyone have data on any of these? Or other ideas? bonus points for things that are done once and keep on saving energy and reducing emissions without any further attention or work.

15 Comments

How we save energy

June 5, 2009 at 4:44 pm (carbon budget, Energy, green living)

global warming I thought I’d list thethings we do as a matter of course to save energy. You can use this list as a resource, an inspiration, or ignore it completely; just please don’t use it as a springboard for guilt, unless guilt actually motivates you to change.And especially don’t guilt-trip if you’re un/underemployed and just trying to get food on the table.

But if you can put aside a few extra bucks, a lot of this stuff gets at 30% tax rebate until 2010, so now’s a great time to make some of these changes. I’d dearly love it if you would find one or more things on this list that make you think, “Hey, I could do that” and then take 3-6 months to work it into your daily life. If you really commit to doing just one or two at a time, five years from now, you’ll be doing all this and more and it won’t even seem like a drudge.

I do recommend writing out all you do to save energy, though. It sure surprised me to write all this out…it’s become so natural that I don’t even think about it any more.

And please, won’t someone write the “Energy Savings 102″ book? It seems like lots of people say “change your lightbulbs” or “throw away your fridge and furnace” but there’s not a lot out there describing realistic steps to take in between. Well, maybe this is the beginning of that list, and y’all can add your own comments of additional steps to take.

Details, details… Read the rest of this entry »

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Carbon Budget – Year in Review

June 4, 2009 at 7:45 pm (carbon budget, Changing habits, Energy, green living)

Goal: 10.25 tonnes
Actual: 14 tonnes

Well, we missed our goal. By a *lot*. We used only about 1 tonne less carbon than last year, so far as I can tell from my less-than-perfect recordkeeping for 2007-08. I’m not happy about it, and I’m not making excuses. I am looking for reasons, though, and ways to cut. But I also feel like we’ve hit a plateau, and it’s going to take some oomph and hard decisions to further reduce our carbon output.

	Goal	Used June 2008-May 2009	Conversion factor	Carbon emitted	US Ave*	Our use as % of US Ave**
Gasoline	300 gal	581 (26,000 miles)	19.35 lb/mi	11,244 lb	1000 gal	58%
Air travel	9500 mi	6715 mi	0.55 lb/mi	3693 lb	2400 mi	280%
Electricity	4500 kwh	4970 kwh	1.4 lb/kwh	6958 lb	11,000 kwh	45%
Propane	400 gal	689 gal	12.7 lb/gal	8750 lb	1100 gal	63%
Wood	1 cord	1 cord	150 lb/cord	150 lb	?	?
Total carbon emissions	10.25 tonnes	14 tonnes	2205 lb/tonne	24,084 lb	22.7 t	48%

* per household, or for 2 people
** Every place you look will tell you a different number for average US carbon emissions per household. To get the average figure of 22.7 tonnes, I used the same conversion factors I used for us and applied them to the US averages I found.

Agonizing detail, including several surprising ways we reduced our impact, after the cut… Read the rest of this entry »

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One Stone Carbon Challenge

March 8, 2009 at 7:32 pm (carbon budget, Changing habits, Energy, green living, You must try this)

If you read this blog, you’re probably familiar with the idea of global warming, and you know that it is going to have serious effects in the coming decades (see this image only if you want to be depressed). You may also know that scientists are suggesting there is a “point of no return” where we won’t be able to stop or reverse global warming. This point is usually described as a ratio of how much carbon (or more accurately, carbon equivalent[1]) is in the atmosphere. There’s some debate about the exact number, but somewhere between 300 ppm and 450 ppm is considered the “safer” level that will prevent the worst of the effects.

Individual people can have a lot of impact on the total CO2 emissions dumped into the atmosphere. The average American household dumps 18 tonnes of carbon equivalents into the air every year. The sustainable level of carbon emissions – that is, the level that every person in the world could emit and keep the greenhouse effect from worsening beyond the point of no return – is one tonne per person per year [source].

If that sounds like a pretty big drop, well…it is. There’s a group of folks who are committing to make that reduction within a year. They’re calling it the Riot4Austerity, and I take my hat off to them for their bold undertaking, and I hope to reduce my carbon to at least 75% below American average in the next 2 years.

But for me, right now, it’s just too much to change all at once. Anyone else out there feel the same way?

I wanted to come up with a more manageable “chunk” to whittle away at, and I wanted to know the relative merits of various actions. Take the bus for 45 minutes or drive 5 miles? Eat 100% local or go vegetarian? Give up the hair dryer or turn off the A/C? Give up my car, or airplane flights? If I can do one thing to reduce my footprint today, which thing should it be? If I can’t give up my car, how else can I make up the difference?

And so, I bring you the One Stone Carbon Challenge. The basic premise is simple: I’ve created a list of activities which produce, on average, one stone (14 lb) of carbon emissions. You choose activities that prevent 14 pounds of carbon equivalent from entering the atmosphere, and you mark one stone off this chart (200Kb PNG). When you’ve crossed off the 157 stones on the chart, you’ve prevented one tonne of carbon pollution.

I’m putting the detailed calculations on a static page, here, to prevent any further clogging of people’s feed readers.

So, let’s make this a formal Challenge, in best blogging fashion. The One Stone Carbon Challenge runs from now until May 1, 2009. Comment below and tell us:

That you’re participating
Your goal – how many stones will you reduce by May 1?
If you like, tell us your current carbon footprint, and at the end, recalculate your footprint and tell us the difference. Feel free to skip this if it sounds too much like a Weight Watchers weigh-in.

Feel free to snag the icon above to post on your blog, for thems what like badges.

I’ll check back in on May 1!

9 Comments

Project help?

January 28, 2009 at 11:45 am (carbon budget, Changing habits, Energy, green living)

Hey, folks-

I’m hatching my next project – sort of a carbon-reduction challenge for those of us not yet ready to go for the 90% reduction levels of the Riot 4 Austerity. I could use a few more pairs of eyes to check my math and help me figure out a few calculations.

If you’re interested in helping out with a couple hours of research and middle-complexity math calculations, drop me a comment. The final product will be available here for free, and your contribution will of course be cited. :

Emily

2 Comments

More about propane

January 3, 2009 at 11:17 am (carbon budget, Energy)

thermometer Last year and this year, we got propane fill-ups in early November and right around New Years. Yesterday’s fill up was 330 gallons; last year’s was 327. This year was colder, though; 2448 heating degree days* as opposed to 2173. So we have, overall, used a bit less propane per heating degree day: 0.13 gallons vs. 0.15 gallons. That means that on Jan. 1, which had 45 heating degree days, we saved 0.9 gallons of propane over last year. That’s almost $2 saved. At this rate, we’d probably save 135 gallons of propane and $300 (minus the price of wood – about $50 so far this year) over the course of the winter.

We’ll see if fixing the leak has a noticeable difference. We’d normally get another fill-up the last week of February, so I’ll update at that point how we’re doing.

* Heating degree days (definition) can be found if you go to the Weather Underground forecast page for your town, scroll down to “Yesterday’s Official Weather and Almanac” and look for “Since July 1 heating degree days.” There’s also a column for normal and last year.

2 Comments