# Average Home Energy Consumption



## velvetfoot (Nov 20, 2012)

I tried to add up my energy consumption for 2011: 3529 kwh, 381 gal of oil, and 3.5 cords of wood, and came up with 141,812,493 BTUs.  Then I found this website that says for NY the average consumption was 102.6 million BTUs.  Needless to say, I'm disappointed.  Could the inefficiency of wood be a factor?  Any other insights or other comparisons?


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## maple1 (Nov 20, 2012)

I'm around 8000kwh, 750 litres of oil, and 7.5 cords of wood. Or was until the boiler swap out of this fall.

3529kwh over a year is something I'd be very happy with.


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## velvetfoot (Nov 20, 2012)

Thanks.  The kwhs will go up some with the electric water heater, the oil should go down some, and I'm I bet the wood consumption will go up with the bigger insert and perhaps cooler temps.


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## Grisu (Nov 20, 2012)

Great idea; I should do that, too. Our electricity use is lower but we also have a natural gas stove and dryer so that is really no special feat. On the other hand, 8000 kWh sounds really high; are you using electricity also for heating?


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## woodgeek (Nov 20, 2012)

With our now all-electric house we are running ~14 MWh/year for all appliances, space heat/cool and DHW. I might burn a quarter tonne of biomass per yr on WEs or when we feel like a fire. My utility says that similar-sized, all electric homes in my area use ~26 MWh/yr on average!

To the OP, I imagine the difference may be related to 'primary' energy BTUs or 'site generated' BTUs, or is that for space heating alone? The average house in the US uses 12.7 MWh/yr of grid electricity, averaging electric heat users with the rest. That would require roughly 120 MBTU/yr of primary FF energy before you count any FF burned on site.

Also for carbon footprint, I would drop the wood from the calc, or score it at 10% of an equivalent FF BTU.


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## maple1 (Nov 20, 2012)

Grisu said:


> Great idea; I should do that, too. Our electricity use is lower but we also have a natural gas stove and dryer so that is really no special feat. On the other hand, 8000 kWh sounds really high; are you using electricity also for heating?


 
It does?

I do think it's a bit much, but when comparing power bills with friends & neighbours ours isn't up there by any means. No electric heating. Our appliances are getting a bit old, have an upright freezer, dryer runs more than it should (clothesline way underused), TV on all the time along with another older CRT one that is hooked up to a PS3 (so it's on a lot). My computer also almost always on 24/7. We could do better, no doubt.


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## sloeffle (Nov 20, 2012)

We use on average around 1350kwh a month. Our house is all electric. I would be very happy with >8MWh usage or less per year.

My total usage:

(12 * 1350) * kwh = 55276694.5 btu
2 cords * 22MBTU cord = 44000000 btu

Total: 99,276,694.5 BTUS - 6 million less than what most Ohioans use.

I have a friend who uses around 3kwh a month on a all electric home. He also has 4 kids in the house and none of them know how to shut a light off. During the summer you can hang beef in house and run around in shorts in the winter so I think a lot of it has to do with personal heating and cooling preferences.

I have geothermal heat / cooling along DHW assist , new hot marathon hot water heater, newer appliances, and CFL bulbs. Outside of spending 3k to spray foam my crawl space and putting kill a watt meter on every plug I am not sure how I would be able to drop my electricity usage any more.


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## pdf27 (Nov 20, 2012)

We're currently using 2100 kWh of electricity and ~10,000 kWh (34 million BTU) of gas per year. Gas should hopefully drop significantly over the next two years as we fit solar thermal and a wood stove.


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## velvetfoot (Nov 20, 2012)

I'm sorry, I didn't include the link in my original post:
http://www.eia.gov/consumption/residential/reports/2009/consumption-down.cfm#fig-4

It looks like that's the energy consumed by a house over the course of a year, neglecting cost.


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## jharkin (Nov 20, 2012)

That 102 million average is interesting. Sounds surprisingly low... I read somewhere that the average us household uses 10,000 kWh of electricity alone... We use around 8000 kWh and we don't have electric heat. Elec stove,dryer and a dehumidifier for the basement are the big loads.

If I add up all our usage we are probably around 160 million, not including gas for the cars.


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## woodgeek (Nov 20, 2012)

jharkin said:


> That 102 million average is interesting. Sounds surprisingly low... I read somewhere that the average us household uses 10,000 kWh of electricity alone... We use around 8000 kWh and we don't have electric heat. Elec stove,dryer and a dehumidifier for the basement are the big loads.
> 
> If I add up all our usage we are probably around 160 million, not including gas for the cars.


 
Digging into the excel sheets, there is a note that it is 'site' or 'delivered' energy *excluding* biomass and solar. By that token, 1 MWh of elec is just 3.4 MBTU. My usage in these terms is 47 MBTU/yr, versus 96 for PA average. My case is 'skewed' by the use of HP tech.

By the same scoring, velvetfoot is using ~62 MBTU/yr of 'site' energy, well below the NY average of 102 MBTU. VF's score is 'skewed' by the use of wood burning tech.


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## jharkin (Nov 20, 2012)

Whenever these threads come up im simply amazed at how little energy many on these boards use. We use about 35mbtu a year just for water heating in a high efficiency gas boiler. And we live in a tiny house. Without the kids that might go down to 25 maybe....

I've gone to all cfl and led lighting, insulated as much as possible without gutting the place, energy star appliances . but still the elec is high.


how do you guys Do it? No TVs in the house? No kids driving up the bills?


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## woodgeek (Nov 20, 2012)

Jeremy...if you count your site energy....3.4 MBTU/MWh, 100kBTU/therm NG, what is your total, omitting biomass BTUs?...prob not 160 MBTU/yr.

In my first year in my house (2005-2006), it appears I used >200 MBTU site energy (prob something to do with the 1350 gals of fuel oil we went through).


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## SmokeyTheBear (Nov 20, 2012)

18.4 MBTU for electricity and 23.8 MBTU for Oil + 71.9 MBTU of Wood Pellets = 114.1 MBTU to run the place with.

Base 65 HDD 7,378 2644 square feet 5.8491 BTU/square foot/degree day


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## Grisu (Nov 20, 2012)

maple1 said:


> It does?
> 
> I do think it's a bit much, but when comparing power bills with friends & neighbours ours isn't up there by any means. No electric heating. Our appliances are getting a bit old, have an upright freezer, dryer runs more than it should (clothesline way underused), TV on all the time along with another older CRT one that is hooked up to a PS3 (so it's on a lot). My computer also almost always on 24/7. We could do better, no doubt.


 
You are right. I just checked the numbers and was surprised to learn that the average household electricity use is 11,500 kWh per year.  So you are below average!

I knew we were conserving energy but by that much? I certainly try to save energy. I mean the TV is not on that much and it is on a powerstrip so I turn it completely off when not in use. Computers go to sleep at night and I even switch off the modem. CFLs/LEDs for most of the house and I am adamant about switching lights off when leaving the room. Some electric baseboard heating but that is getting less thanks to the woodstove. Stove and dryer run on gas that certainly saves a lot. However, maybe the biggest contributor is that no one is at home during the day plus we do not have energy hogs like an airconditioner. Still, I think most of the savings come from behavioral changes. I just do not take electricity for granted.


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## DBoon (Nov 20, 2012)

I'll throw mine into the mix - ~4200 kWh, 400 gallons of oil and 1.5 cords of wood = 103MBtu. 

It's probably tough to be better than that in a heating climate. If I lived in an apartment in NY City or California, I am sure that I could beat it by a lot.


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## Grisu (Nov 20, 2012)

I just checked our energy consumption and wish I would not have done it. I thought we were doing much better than we are apparently. 
All numbers Oct 2011 to Oct 2012:

Electricity:      2800 kWh      9.5 mill BTU
Wood:            2.5 cords     54.0 mill BTU
Kerosene:     100 gl           13.5 mill BTU
Natural gas:   324 ccf        33.1 mill BTU
Total:                               110.1 mill BTU

That is pretty close to average for the northeast. I would have never thought that the wood would supply that many BTUs. I guess I have to look to insulate the place further then.


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## woodgeek (Nov 20, 2012)

take a pill people, the EIA numbers velvet cites are **excluding** biomass BTUs.


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## SmokeyTheBear (Nov 20, 2012)

woodgeek said:


> take a pill people, the EIA numbers velvet cites are **excluding** biomass BTUs.


 
Which makes them incomplete.


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## jharkin (Nov 20, 2012)

WG...

Without wood I figure about 135 mbtu.

Big one is natural gas, its an old house and the heat is gas fired steam (85% boiler tho, about as good as it gets on steam), with an indirect for hot water. We burn350 therm a year for hot water and then another 600-700 for heat (+1.5 cord wood). 


Electric runs 600-700 kWh in the winter and pushing 1000 in the summer. Basement dehumidifier is a big culprit and my wife is home full time with the kids so we are using it 24/7. 2 babies... Lofts of laundry also driving up the bill.


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## Seasoned Oak (Nov 20, 2012)

I remember reading the average home in Pa use about 75 million Btu per heating season. Im assuming for heat.  I use at least 100 million.


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## jebatty (Nov 21, 2012)

Always interesting and informative to review energy usage. Our house is 100% electric + heat from a wood stove. Total electric last 12 months = 11,113 kwh = 37.8 Mbtu. Total wood burned same period = 4 cords aspen = 13.7 x 4 = 54.8 Mbtu. Total energy usage = 92.6 Mbtu.

Electric breakdown (3 meters on our system):
DHW = 1,266 kwh = 4.3 Mbtu (=  0.31 cord of aspen equivalent)
Heat = 3,393 kwh = 11.5 Mbtu (= 0.84 cord of aspen equivalent)
General = 6,454 kwh = 21.9 Mbtu (= 1.6 cord of aspen equivalent)

Our electric bill is about $1200/yr for energy equivalent to 2.75 cords of aspen, or $436/cord of aspen. I would gladly cut, split, stack and burn another 2.75 cords of aspen if I had a way to do that to eliminate my electric bill.


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## velvetfoot (Nov 21, 2012)

Yeah, the EIA numbers exlude biomass, but really, how many people use it?
My place is only 2000 ft2, that's 71000 btu/ft2.


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## jebatty (Nov 21, 2012)

Our home is 1500 sq ft main level (+ 1500 sq ft basement which is heated to about 50F). Using 1500 sq ft main level as the heated space, ours works out to 44,200 btu/sq ft. Our heating degree days base 70 for this same 12 month period was 9839.


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## TradEddie (Nov 21, 2012)

Unless you have a specific reason, you should use 65 as the base for your HDD, not 70. The base temperature is not the thermostat temperature, it is the exterior temperature where you do not need heating. It's not a huge difference, but unless we start off comparing apples with apples, we get nowhere.

While I'm impressed by the low levels of energy consumption sometimes reported, I'm usually even more shocked at the high levels people report. I will not suffer discomfort to save money, but if I had some of those bills, I'd suffer.

I'll get exact figures later but I estimate 100MBTU, total energy use for 4 people in a 2300sqft heated space.

TE

Edited to correct massive miscalculation.


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## jebatty (Nov 21, 2012)

Base 65 HDD = 8288


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## TradEddie (Nov 21, 2012)

Annual electricity 10400kwh = 35.5 MBTU
Average Propane: 591 gal = 54 MBTU
Wood, varies widely: 1 cord = 22MBTU

Total Energy useage 111.5 MBTU

2400 sqft, 5000 HDD
Comes to 7BTU/sqft/HDD for heating, considering the inefficiency of wood heat and a 30 year old house, not too bad.


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## Slow1 (Nov 21, 2012)

Interesting thread here - Looks like we're way ahead on the electric usage, but overall energy consumption is above average for our area.  I'm calculating a total of about 127Mbtu - the average based on that link was about 110 for my area.  My breakdown is:

Electric 5,880 Kw/yr 20 Mbtu
Oil 220 Gallons/yr 30.8 Mbtu
Wood 3.5 Cords/yr 75.6 Mbut
Total - 127 Mbtu

I guess we just like to burn our wood   Our oil use is for our hot water almost exclusively - interesting that it is about 25% of our total home energy use which seems to be pretty much in line with averages I've read although I can't cite one off hand.


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## tlc1976 (Nov 21, 2012)

Have not used propane since 2006
Electric about 6000 kwh/yr = 20.5 MBTU
Wood about 2 cord/yr = 44 MBTU
Total = 64.5 MBTU/yr

This is with just me here and my daughter sometimes. Back when I had a wife and her kids here a year ago, electricity use was nearly triple. Am waiting for the electric company to think there is something wrong with my meter . I don't consider myself a miser with electric use. All my satellite equipment stays on standby. Porch light stays on 24/7 and a couple other lights stay on all night. Computer stays on 24/7 but I shut the CRT monitor off. I play music and run stereos and amps. Often I will run a space heater at my feet when sitting at the computer, or keep one going if I'm gonna be gone for a really cold weekend so the pipes don't freeze. Which is all included in the electric use. And I might go through less wood this winter with nobody feeding the fire all day.


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## legrandice (Nov 21, 2012)

Wow...this is quite a bit of data.

We use around
6000Kwh/yr
200 Gal oil
4 cords wood


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## TradEddie (Nov 21, 2012)

I think that as soon as we add wood to the BTU consumption, it is going to disproportionately skew the overall number, firstly because of the inefficiency of the average wood stove, and secondly because stoves usually result in room temperatures far higher than anybody would pay to get using oil or gas.  Imagine the bill to keep several rooms at 80F using fossil fuels or electric?

TE


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## jharkin (Nov 21, 2012)

Thats the thing... Its hard to keep the usage down when you are the only person in the household who has any interest in conservation.

If I lived alone I'd be using only a fraction of what I do. But I cant complain.


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## velvetfoot (Nov 21, 2012)

Is that the 1050 ft2 chalet?


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## velvetfoot (Nov 21, 2012)

Could a wood boiler contribute to lower overall household energy use then?  More like a conventional central heating system?  The accepted theory is that area heating allow lower overall energy use.


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## tlc1976 (Nov 22, 2012)

velvetfoot said:


> Is that the 1050 ft2 chalet?


 
Yes that use is for me.

I'm not totally sure what her electric bill is though from what she said it used to be similar to mine + about $100 which accounted for running an Edenpure 24/7.  She said she used "some" propane, which I know to be 1 fill a year but that's all.  Besides the pellet stove has only been in place a couple months.


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## maple1 (Nov 22, 2012)

Geez, you guys are all making me feel very bloated. 

Just converted my consumptions from page 1 to MBTU. I just converted by factoring from other peoples conversion recipes.

750 l. oil = 33 MBTU
8000 KWH = 27 MBTU
7.5 Cords Wood = 162 MBTU.

Total 222 MBTU. Zoinks.

I made some big changes here this fall - got rid of the oil all together (it did our backup heat & non-heating season DHW) by yanking the oil/wood boiler, and put in an 80 gal. electric hot water heater, gassifying wood boiler & electric boiler for backup heat (backup heat rarely gets used). So kind of curious to see what my numbers wll be at the end of next year. Oil will go to zero, wood will be reduced hopefully considerably, electric up hopefully minimally. The big one, wood, is pretty darned fuzzy - my wood is a hodgepodge of old rotten trash & decent hardwoods. But it's a FREE (neglecting equipment capital costs & my time) renewable resource from my back yard - I think its quite a skew to the numbers.


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## sesmith (Nov 24, 2012)

We're all electric and located in central NY (about 7200 annual HDD). Last 12 mo's electric use total was
12627 kwh or 43.1 MBtu. We heat the whole house (1400 sq. ft, 170 year old house) and set the tstat to 67 without any setbacks, and air condition to 72 as needed. We cheat, though...GSHP. To the OP, when I used to heat primarily with a wood stove located in my cellar, the btu #s were skewed higher using wood (over our existing oil furnace at the time). I figured this was due to the inefficiencies of the stove and having the wood stove in the cellar, more than anything.


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## sesmith (Nov 24, 2012)

velvetfoot said:


> I'm sorry, I didn't include the link in my original post:
> http://www.eia.gov/consumption/residential/reports/2009/consumption-down.cfm#fig-4
> 
> It looks like that's the energy consumed by a house over the course of a year, neglecting cost.


 
You would expect the higher users by state to be the states with the highest heating dominated climates.  But what's up with New Jersey.  I mean, really.


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## woodgeek (Nov 24, 2012)

NJ is one of the wealthier states == more square footage.


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## sesmith (Dec 1, 2012)

sesmith said:


> We're all electric and located in central NY (about 7200 annual HDD). Last 12 mo's electric use total was
> 12627 kwh or 43.1 MBtu. We heat the whole house (1400 sq. ft, 170 year old house) and set the tstat to 67 without any setbacks, and air condition to 72 as needed. We cheat, though...GSHP. To the OP, when I used to heat primarily with a wood stove located in my cellar, the btu #s were skewed higher using wood (over our existing oil furnace at the time). I figured this was due to the inefficiencies of the stove and having the wood stove in the cellar, more than anything.


 
Revisiting this thread.  One thing I noticed before, is that the low #s from my house and Woodgeek's had heat pump technology in common.  I re-ran the #s for my house from the time before we had the geo system installed.  In the years we heated with wood it ran around 179 MBtu (averaged 6.5 cords wood and 20-50 gal oil) and in oil only years (no wood heat) around 135 MBtu. 

The higher #s for wood show the inefficiencies of heating with wood, especially with a stove located in the cellar.  More importantly, though, it shows just how much energy use is reduced, on site, by switching to heat pump technology, at least in the northeast, where we do a lot of heating.  Now I know there's the argument about taking the inefficiencies of the electrical grid into consideration.  In my case, I pay a little more for wind energy for all my electricity, so I can at least feel good about supporting the wind industry.  There's also the economics to consider when determining whether it's a good idea to switch over to a heat pump system, and what combination of insulation and tons of heating system make the most sense for a particular house.  But in the future, whether it's new construction or retrofitting old housing stock, using heat pumps, whether ground source, or the newer air source units, seems like a no-brainer to me for decreasing residential energy use.


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## woodgeek (Dec 1, 2012)

As much a fan as I am of HP technology (I can go on and on about it) I still think 'primary energy' is a better measure than site energy. Just switching from an oil boiler to a ASHP looks to reduce your site energy massively, but does little to reduce your carbon footprint (depending on where you live). Not unlike the coal powered EV story.

Of course, if you are getting your kWh from a non-fossil source, then the primary energy can be the same as the site energy. So, like EVs, HPs are only really green if you source your energy appropriately.

But lest you think I am some sort of green snob, I put in an ASHP for the old fashioned reason that it was cheaper than than any other option over the 10 yr timeframe, even when a wind power surcharge is added.  The rest is green gravy.


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## sesmith (Dec 1, 2012)

woodgeek said:


> But lest you think I am some sort of green snob, I put in an ASHP for the old fashioned reason that it was cheaper than than any other option over the 10 yr timeframe, even when a wind power surcharge is added. The rest is green gravy.


 
Yea, same here.  In my case, even a ground source system was way less expensive than staying with oil as we figured a simple payback of less than 7 years over oil (with the federal incentives in the mix).

Not cheaper than cutting wood off my property for sure, but an injury forced me out of that game.  I can say that I couldn't buy firewood for less than the geo system costs to me tor run.


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## maverick06 (Dec 3, 2012)

10/25/10 - 10/24/2011 
hot water consumption 2650 kwh 9.01 mbtu
general power 8750 kwh 29.75 mbtu
wood   2.3 cords 50.6 mbtu
oil   30 gal 4.23 mbtu
total       93.59 mbtu

10/24/11 - 10/23/2012 
hot water consumption 2379 kwh 8.0886 mbtu
general power 8748 kwh 29.7432 mbtu
wood   2.2 cords 48.4 mbtu
oil   5 gal 0.705 mbtu
total       86.9368 mbtu


Alright, lots of data here. Here is mine for the last 2 year s(based on the dates listed).
The house is 1800ft^2 split level of 1950's construction, and certainly not great insulation.
It is electric hot water, cooking, and a space heater in my daughtes room. She is a year and a half old, so its kept pretty warm.
The house is heated with wood, and a heat pump, with oil fired backup. Oil use is estimated based on the fuel gages, thats rough. Same for wood use, guessing the use. Heat pump use is very hard to estimate BTU delivered to the house, all I can do is cite the power consumption (here).
So I am doing ok, could be better. As everyone else seems to say, its hard being efficient when others in the house arent working very hard at it. Of course I am the guy who likes turning on the 600watt christmas tree that I have!


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## freddypd (Dec 6, 2012)

10,429 KWH Oct 2011
12,400 KWH Oct 2012 after adding inground pool with heat pump $2285.64 42.31 MBtu??
Electric oven, stove, dryer and central a/c

850-950 gallons oil $3300-3600 ouch....before installation of wood stove

Guesstimating 5 cords wood? Hoping for less but our stove seems to be eating wood.

Did I miss how to figure out MBtu? I did find one calculator for KW.


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## BrotherBart (Dec 6, 2012)

I am doing a test tonight of using the electric radiator backups for the first time to see if they can hold the place around 68 to 70. Watching the whole house power monitor is painful. 35 outside and kicking an average of 3 kwh per hour since noon. Probably gonna be a fire in one of the wood stoves tomorrow.


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## woodgeek (Dec 7, 2012)

freddypd said:


> 10,429 KWH Oct 2011
> 12,400 KWH Oct 2012 after adding inground pool with heat pump $2285.64 42.31 MBtu??
> Electric oven, stove, dryer and central a/c
> 
> ...


 
Oil is 139,000 BTU/gal, so 900 gals is = 125 MBTU
Hardwood is ~23 MBTU/cord, so that is 115 MBTU

You total would now appear to be ~155 MBTU.

It seems unlikely that you dropped your MBTU when you switched fuels. Either your 5 cord estimate is short, or you reduced your heating load when you you switched. Or your oil boiler is from the stone age.


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## freddypd (Dec 7, 2012)

woodgeek said:


> Oil is 139,000 BTU/gal, so 900 gals is = 125 MBTU
> Hardwood is ~23 MBTU/cord, so that is 115 MBTU
> 
> You total would now appear to be ~155 MBTU.
> ...


 
This is my first heating season with wood. People have told me I would use 3-5 cords of wood per year. The season barely started and I probably used 1/2 cord already! I guess I will go over the 5 cord estimate. I dont think I have more than 5 cords seasoned.

OK MBtu is not an efficiency thing, it is how many BTU's of energy my home requires? I was thinking the lower number the better?

Thanks for the calculations woodgeek.


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## Slow1 (Dec 7, 2012)

BrotherBart said:


> I am doing a test tonight of using the electric radiator backups for the first time to see if they can hold the place around 68 to 70. Watching the whole house power monitor is painful. 35 outside and kicking an average of 3 kwh per hour since noon. Probably gonna be a fire in one of the wood stoves tomorrow.


 
That does sound bad - is that just maintaining or trying to raise the temp?  I too have a whole house monitor (TED5002) and sometimes I think it is a mixed blessing - too much knowledge drives the rest of the family crazy.


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## jharkin (Dec 7, 2012)

freddypd said:


> OK MBtu is not an efficiency thing, it is how many BTU's of energy my home requires? I was thinking the lower number the better?


 
MBTU is shorthand for Million BTU.




TradEddie said:


> 2400 sqft, 5000 HDD
> Comes to 7BTU/sqft/HDD for heating, considering the inefficiency of wood heat and a 30 year old house, not too bad.


 
That sounds pretty darn good to me. Ive read the average HHI  for US houses is around 10,code minimum new construction gets you to 7 and super tight houses hit 5ish.

When I calculate mine I get 9.7 on a net energy basis, and about 12 on a gross input basis.(I never remember which is the proper way to estimate?) Not great but I think not bad for the age of the house and a lot better than the 12/15 values I calculated from before I started insulating and sealing. I'd love to get it down to 10 gross but that will be difficult with this place.


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## TradEddie (Dec 7, 2012)

freddypd said:


> This is my first heating season with wood. People have told me I would use 3-5 cords of wood per year. The season barely started and I probably used 1/2 cord already! I guess I will go over the 5 cord estimate. I dont think I have more than 5 cords seasoned.
> 
> OK MBtu is not an efficiency thing, it is how many BTU's of energy my home requires? I was thinking the lower number the better?
> 
> Thanks for the calculations woodgeek.


 
What size house are you heating? Your year-round electric is comparable to mine, but your oil cost is so much higher than my propane. When you say 1/2 cord used, do you mean a "real" cord (4x4x8) or a face cord?

BTU is simply a measure of energy, 125MBTU oil, at 90% furnace efficiency is 112.5 MBTU.  To get 112.5 MBTU from wood at 70% efficiency you'd need 160MBTU, which is 7 cords.  That's what some 24/7 burners in very cold places use in a season. Your existing furnace might only be 70% efficient, in which case you'd only need just over 5 cords. Maybe if you have an inefficient furnace, and inefficient distribution system, you'd need less wood.

An crude way to compare heating efficiency is BTU/HDD/SQFT, but people have such varied heat use, it can only give you a rough guide. For single family homes, under 5 is great, 5-10 is okay, over 10 has lots of room for improvement.  Use only the BTU for heating.

TE


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## TradEddie (Dec 7, 2012)

jharkin said:


> MBTU is shorthand for Million BTU.
> 
> 
> 
> ...


 
I use gross energy, that's what I pay for, so any reduction is $ in my pocket. I'm pleased with our house, built in 1977 but with R13 in walls and R5 foam outside, much higher than typical of the time, although the foam may have been added later.  Attic insulation is just okay, but having a cape minimizes that area anyway. On the other hand, the access doors behind knee walls were simply a particle board with 1/2" gap at the top, and there are still so many other air leaks that I'll never get them all.  I know my house is still far from ideal so I think that the "average" number of 10BTU/HDD/SQFT is misleading because it doesn't account for different use patterns.  Our propane heat is setback daytime Monday-Friday, or if we're off for the weekend, while others keep their home at 75F 24/7 all winter long.

TE


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## jharkin (Dec 7, 2012)

TradEddie said:


> I use gross energy, that's what I pay for, so any reduction is $ in my pocket. I'm pleased with our house, built in 1977 but with R13 in walls and R5 foam outside, much higher than typical of the time, although the foam may have been added later. Attic insulation is just okay, but having a cape minimizes that area anyway. On the other hand, the access doors behind knee walls were simply a particle board with 1/2" gap at the top, and there are still so many other air leaks that I'll never get them all. I know my house is still far from ideal so I think that the "average" number of 10BTU/HDD/SQFT is misleading because it doesn't account for different use patterns. Our propane heat is setback daytime Monday-Friday, or if we're off for the weekend, while others keep their home at 75F 24/7 all winter long.
> 
> TE


 

Thats a good point. The 15 gross value at my place before we started insulating was also a time that my wife and I both worked full time and I had the heat setback to 62F daytime and 64 or 65 at night when asleep. Now we have two toddlers in the house and my wife is home full time the heat is at 68 all the time and i know she kicks it up to 70 a lot when I'm not home (when I am home the stove is lit  ). So the improvement to 12 gross is probably even better than it looks.


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## TradEddie (Dec 7, 2012)

Beautiful house, paying a little more to heat something like that is a small price to pay. If you're counting wood in your gross calculation, then its not so bad either, since you're getting lower efficiency per gross BTU, and you're heating the house much more.
I'm not out to save the earth or pinch pennies, but the less I spend on heating, the more I have for fun stuff.

TE


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## Slow1 (Dec 7, 2012)

So I ran my numbers and came up with something like 9Btu/HDD/sqft.  I counted all household energy (electric, DHW heating, and wood).  It seems odd to include the DHW and electric as these are not really directly heating related and the measurement is /HDD.  

In any case, with a family of 6 being below the average of 10 perhaps is a good thing - I don't know if that will hold as we start heating a bit more and thus consume more wood, but time will tell.  Not to mention once the kids get old enough to start taking daily showers (or more often!?! I hear that teens today do?) and running up the DHW costs....


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## jharkin (Dec 7, 2012)

TradEddie said:


> Beautiful house, paying a little more to heat something like that is a small price to pay. If you're counting wood in your gross calculation, then its not so bad either, since you're getting lower efficiency per gross BTU, and you're heating the house much more.
> I'm not out to save the earth or pinch pennies, but the less I spend on heating, the more I have for fun stuff.
> 
> TE


 
That is wood included. And the reason I work out the net numbers is I wanted to very specifically check what differnece the insulation is making, normalizing out variations in how much of my heat Im getting from wood (72% eff) vs gas (83% eff)  Last year we didn't burn much due to the weather and the kids,  about 1 cord wood and 570 therms of gas to heat over a mild 4700 HDD winter.  This year extrapolating Nov numbers across a more typical 5500 HDD winter I'm on track to burn about 2 cord and 450 therms.

Overall I think its pretty darn good for this old place, I know our friends with old stone houses (BBar, Joful, Danno, etc) would probably kill for numbers so low...


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## woodgeek (Dec 7, 2012)

Slow1 said:


> So I ran my numbers and came up with something like 9Btu/HDD/sqft. I counted all household energy (electric, DHW heating, and wood). It seems odd to include the DHW and electric as these are not really directly heating related and the measurement is /HDD.
> 
> In any case, with a family of 6 being below the average of 10 perhaps is a good thing - I don't know if that will hold as we start heating a bit more and thus consume more wood, but time will tell. Not to mention once the kids get old enough to start taking daily showers (or more often!?! I hear that teens today do?) and running up the DHW costs....


 
OF course when there are two ways of computing anything there are groups of people doing it both ways....but IMO, to characterize the insulation/tightness of your house envelope, I think you should use the 'net delivered BTU' for space heating, divided by the HDD (using your tstat setpoint as a base) divided by your conditioned square footage. I would call this a home heating index HHI.

On these terms, I started at 12, and am now 6-7.

This way, HHI doesn't depend on occupants, setbacks, or your fuel source and is a property of the house itself. If you crank the heat, your energy usage goes up, but your HHI doesn't.


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## jharkin (Dec 7, 2012)

woodgeek said:


> OF course when there are two ways of computing anything there are groups of people doing it both ways....but IMO, to characterize the insulation/tightness of your house envelope, I think you should use the 'net delivered BTU' for space heating, divided by the HDD (using your tstat setpoint as a base) divided by your conditioned square footage. I would call this a home heating index HHI.
> 
> On these terms, I started at 12, and am now 6-7.
> 
> This way, HHI doesn't depend on occupants, setbacks, or your fuel source and is a property of the house itself. If you crank the heat, your energy usage goes up, but your HHI doesn't.


 

Wow there are a lot of ways to do this. Every article I can find talks about using the default 65 as the HDD basis - which is what I did. If I used the actual indoor temp of say 70 my numbers would be even better. I know that my house doesn't typically need any heat at all till the outside temps start falling into the 50s.

Using 65 base HDD and net energy my usage has gone from 11.8 down to 9.7 with insulation improvements over 3 years. 

If I guess at the tstat set point and rework the numbers its probably more like 11.5 (with an average inside temp of 66) 3 years ago  down to 8.2 last year (average inside temp close to 70)Even this is probably not quite right because I'm not figuring all the wood heat days where the average inside temp is more like 75 
I'


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## freddypd (Dec 7, 2012)

TradEddie said:


> What size house are you heating? Your year-round electric is comparable to mine, but your oil cost is so much higher than my propane. When you say 1/2 cord used, do you mean a "real" cord (4x4x8) or a face cord?
> 
> BTU is simply a measure of energy, 125MBTU oil, at 90% furnace efficiency is 112.5 MBTU. To get 112.5 MBTU from wood at 70% efficiency you'd need 160MBTU, which is 7 cords. That's what some 24/7 burners in very cold places use in a season. Your existing furnace might only be 70% efficient, in which case you'd only need just over 5 cords. Maybe if you have an inefficient furnace, and inefficient distribution system, you'd need less wood.
> 
> ...


I have a ranch house about 2000 sq feet. 2x4 walls have been re insulated, attic insulation is not that great, windows replaced, vinyl siding with foam boards underneath.
My wife really does try to keep the heat down, but I am ALWAYS cold so I usually bump it up. Now we are only running the bedroom zone at night at about 63-65. Living areas have been off since the new install of the wood insert!

My furnace is probably circa 1998? Oil fired. My DHW is independent and fairly new.

We have probably used 1/2 cord 4'x4'x4' so far this year. We do keep the room that the insert is in at 75-78! Like I said I am always cold.

I want to get more efficient and save money. I have an insulation contractor coming Tuesday. I guess I will see what he has to offer.

Thanks for the reply.


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## Slow1 (Dec 7, 2012)

woodgeek said:


> OF course when there are two ways of computing anything there are groups of people doing it both ways....but IMO, to characterize the insulation/tightness of your house envelope, I think you should use the 'net delivered BTU' for space heating, divided by the HDD (using your tstat setpoint as a base) divided by your conditioned square footage. I would call this a home heating index HHI.
> 
> On these terms, I started at 12, and am now 6-7.
> 
> This way, HHI doesn't depend on occupants, setbacks, or your fuel source and is a property of the house itself. If you crank the heat, your energy usage goes up, but your HHI doesn't.


 
I suppose the real answer then depends on what the question is that one is asking?  Your method would seem to answer the question of "how efficient is the house as a whole in terms of being able to retain/utilize the heating within."  My question may be "Is my net energy usage on par with others in terms of a) total energy used in the home and b) total energy used considering the size of the home"  Clearly each of these questions would require a slightly different calculation.

For some the only question is "how can I further optimize for $'s" over some given period of time while perhaps maintaining some preferred level of comfort.  

At any rate, what I'm interested in knowing is more like the questions I asked as "my question" above - I really feel I've done a decent amount to reduce our overall energy consumption, but I'd like some objective measure on which to know if our household really is ahead of the curve in terms of energy use or not - yes, a bit competitive and likely meaningless but encouraging to me as I pursue further improvements.


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## Seasoned Oak (Dec 7, 2012)

jharkin said:


> . Now we have two toddlers in the house and my wife is home full time the heat is at 68 all the time and i know she kicks it up to 70 a lot when I'm not home (when I am home the stove is lit  ).s.


My wife sits around with a coat on at 75, we keep the kitchen and bath 77 LR 75 and BR 74  When the wood stove is going Floor 1 is 82 , Floor 2 is 77, Floor 3 is 74.


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## DBoon (Dec 7, 2012)

Just calculated my BTU/HDD/Sqft.
1250 square feet, 7500 HDD base 65, 89MBTU for heating, so 9.5 - considering it is a 1922 house, I guess I'm doing ok after all my insulation and weathersealing.  I have a little more insulation to add in the attic....maybe I can get below 9 next year.


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## woodgeek (Dec 8, 2012)

Slow1 said:


> At any rate, what I'm interested in knowing is more like the questions I asked as "my question" above - I really feel I've done a decent amount to reduce our overall energy consumption, but I'd like some objective measure on which to know if our household really is ahead of the curve in terms of energy use or not - yes, a bit competitive and likely meaningless but encouraging to me as I pursue further improvements.


 
I've got a link for that....

https://www.energystar.gov/index.cfm?fuseaction=home_energy_yardstick.showgetstarted

I don't really like this tool, but if I understand what it is doing, it computes your total site energy usage and then reports your percentile rank compared to other homes in your general area.  I currently get a 7.3, which I think means that I use less site energy or produce less CO2 than 73% of homes in my area. I think it is probably a CO2 footprint score, and I would guess that it scales by conditioned floor space?? I could prob back out what it is doing by putting in different square footage, same BTUs of different fuels, etc, but I haven't bothered with that yet.

But it is what you asked for: a single number score comparing you by some metric to your neighbors.


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## jharkin (Dec 8, 2012)

Ug...I get a 2.8 on that tool.


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## jebatty (Dec 8, 2012)

Calculation based on Mbtu/hdd/sqft for our house, base 65:

Heat only (elec + wood) = 5.3
Total energy usage = 7.5


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## TradEddie (Dec 9, 2012)

woodgeek said:


> I've got a link for that....
> 
> https://www.energystar.gov/index.cfm?fuseaction=home_energy_yardstick.showgetstarted
> 
> ...


 
This could be a very nice tool, but completely wrong calculation numbers, so its hard to know if it means anything at all, 1 kw/h is 11 KBTU, 1 cord is 17.7MBTU?

TE


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## woodgeek (Dec 9, 2012)

TradEddie said:


> This could be a very nice tool, but completely wrong calculation numbers, so its hard to know if it means anything at all, 1 kw/h is 11 KBTU, 1 cord is 17.7MBTU?
> 
> TE


 
These numbers make sense....To make 1 kWh of electricity requires 11kBTU of fuel to be burned at the power plant, at something like 30% efficiency.  17.7MBTU sounds like a typical number for wood (low for hardwood, but not crazy)


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## woodgeek (Dec 9, 2012)

Ok. I played with the yardstick site.  It appears to rank you on total primary BTU (not site), compared to households in your area with the same square footage and number of persons.   It reports CO2, but does not appear to factor that in.


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## TradEddie (Dec 10, 2012)

I see, thanks for the explanation, I would never have thought of that.  So now I can feel proud of my score, although grading on the curve of average homes in the Philly suburbs isn't exactly a high standard.  One of the many flaws in any such comparison, but nonetheless useful.

TE


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## Slow1 (Dec 10, 2012)

woodgeek said:


> Ok. I played with the yardstick site. It appears to rank you on total primary BTU (not site), compared to households in your area with the same square footage and number of persons. It reports CO2, but does not appear to factor that in.


 
I tried it and ended up in the 9.3 range, but if it is going with "primary" energy that means it is considering the electric cost higher as they assume loss due to transmission etc, right?  If that is the case someone running on solar should be able to indicate that is it would make a material difference, wouldn't it?


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## woodgeek (Dec 10, 2012)

TradEddie said:


> I see, thanks for the explanation, I would never have thought of that. So now I can feel proud of my score, although grading on the curve of average homes in the Philly suburbs isn't exactly a high standard. One of the many flaws in any such comparison, but nonetheless useful.
> 
> TE


 
What's your score??


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## TradEddie (Dec 10, 2012)

If you're feeling really geeky, you can see the distribution curve for the inputted home by viewing the HTML source code...
If you have solar, just don't enter the solar kWh.

Either way 9.3 is very impressive based on what I saw with the distribution, you listed your BTU/HDD/SQFT earlier, what were the numbers that went into that? 

TE


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## TradEddie (Dec 10, 2012)

woodgeek said:


> What's your score??


 
7.3, without correcting for using only hardwoods.  1 cord wood use is an estimate/aspiration now that I've switched from a slammer insert to an EPA model. 2 cords was typical for previous years, which comes out at 6.3. Based on what I see so far, I may end up using similar quantity of wood, but much less propane, which won't help my score, but will help my pocket.

I'm also expecting improvement this year after completing multi-year widow sash replacement project, massive air-sealing mission, insulating rim joists, and recent block-off plate installation. Last year's record mild winter prevented me seeing if any of that work was visibly worthwhile.  With the imminent end of PECO off-peak electricity, next step is probably an on-demand water heater.

TE


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## woodgeek (Dec 10, 2012)

TradEddie said:


> If you're feeling really geeky, you can see the distribution curve for the inputted home by viewing the HTML source code...
> If you have solar, just don't enter the solar kWh.


 
Nice. Got it. Found my score vs MBTU and dumped into excel. But then I realized that it is only for my 'matched home' in my area. Anyway faster than putting in a bunch of numbers!

If I derate the 50% wind power I buy as 1 kWh = 3400 BTU, then my primary drops to ~120 MBTU and my score goes up to 9.3. If I bought all wind power (or hydro) I would get to 9.9 out of 10.


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## Slow1 (Dec 10, 2012)

TradEddie said:


> If you're feeling really geeky, you can see the distribution curve for the inputted home by viewing the HTML source code...
> If you have solar, just don't enter the solar kWh.
> 
> Either way 9.3 is very impressive based on what I saw with the distribution, you listed your BTU/HDD/SQFT earlier, what were the numbers that went into that?
> ...


 
Ok - I updated my numbers as I now have my Nov elec usage (it was ommitted last time) so taking my last 11 months of usage and extrapolating it to 12 months I get an annual rate of 4,939Kwh, then 220 gallons of oil (my DHW mostly, a bit of heating as well), and then 3.5 cords of wood (high end of my average).  I put in 2500sqft even though we have a bit more than this and we really don't use the basement for anything other than storage.  We have 6 in the house.  So with these numbers I end up with a 9.2 (10MtCo2Equiv).  Now, if I do as you suggest and take the electric to 0 (solar generated, we have had a net over-production in the last year, maybe I should put in a negative number? ha!) then I end up at 9.9 (9MtCo2Equiv).

A couple other interesting points - it seems they do calculate fractional parts of cords as even though it displays 3.5 as 4 in the report, when I put in 4 cords it makes a difference in the end result.  Also it would seem helpful if they would put a bit higher precision on the MtCO2Equiv as going from 10 to 9 doesn't really seem to be all that much of a difference and I suspect there is some rounding there.

All in all an interesting diversion I suppose, not sure it will change any actions.  Their suggestions are clearly not tailored to the results as their suggestions are all very generic.


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## TradEddie (Dec 10, 2012)

5000kWH for 6 people is impressive, doing at all solar is even more so.

That tool counts wood as full CO2 emission, which is not fair.  However, I have to credit it for showing me how much my electricity usage contributes to my carbon footprint, I knew it in the abstract, but hadn't realized how much, I would have expected my propane to be a much higher proportion.

Not that I'll do anything about it, I'm a terrible hypocrite when it comes to climate change, I'll conserve to save money, but at present I'm not prepared to pay anything extra for wind or hydro when the majority of the population is making no effort whatsoever to reduce CO2. That's why I favor a carbon tax, to kick my ass into gear, and 200 million others at the same time.

TE


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## Slow1 (Dec 10, 2012)

TradEddie said:


> 5000kWH for 6 people is impressive, doing at all solar is even more so.
> 
> That tool counts wood as full CO2 emission, which is not fair. However, I have to credit it for showing me how much my electricity usage contributes to my carbon footprint, I knew it in the abstract, but hadn't realized how much, I would have expected my propane to be a much higher proportion.
> 
> ...


 
Honestly I never expected that we'd make it that low either, but we've been chipping away at it over the last 5 years or so.  We dry our clothes almost fully on the line now (by the stove in the cooler months, outside on the deck in the summer) and the kids are well trained at turning off lights etc.  Even burning wood has helped as we don't need the fans to circulate the heat of the central oil heat.  I expect we are at the low point now though as the kids are getting older and I'm sure our power demands will increase over time - if nothing else cooking demands will shift some.  I really am out of ideas on how to reduce further around here - we have LED's in our main lights (those that may be on 12-16hrs on some days), CFLs in others and very few incandescent bulbs left (there are some as not every light is used enough to justify the cost of upgrading).  The refrigerator may be the next change, but that won't likely save me anything as the wife has her eyes on a larger capacity model to avoid having to shop as frequently once the kids get more 'grown up' appetites going.  As it is we buy 4-5 gallons of milk when we go shopping each week so you can imagine what it may be like later!

I'm not really a big fan of counting CO2 emissions as a way of measuring things as it really does seem to be very abstract.  Then again, I suppose Mbtu's aren't all that much more concrete really.  I think that tool is tilted in favor of showing improvements in electric usage making a difference though.  It seems that when I adjusted my wood consumption down it didn't make nearly the difference I expected it would compared to electric changes.

I am not a huge "climate change / save the earth" type either, but I don't care for waste in general.  I'd like to think that even though we're a larger family than the average we still consume at or below the average resources.  We re-use most everything we can etc - we've adopted a lifestyle that goes beyond turning off lights.  The funny thing is that beyond the clothes hanging up and folks who notice the lights not being on in parts of the house we aren't using (and habit of turning lights off in unused rooms, even in other people's houses at times - funny when a 3yo does it actually), I don't think most folks would realize just how 'green' we live - and I like it that way as we don't feel we've given anything up.


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## jebatty (Dec 11, 2012)

Using the tool I have a score of 6.2. It likely should be adjusted because I burn aspen at 13.7 Mbtu/cord, and the 17.7 Mbtu for wood is not accurate for me. A few other comments.

Electricity at 30% is pretty accurate for a coal-fired plant and electricity available at the plant. But this does not include the energy used in mining, transporting, and handling the coal before it is burned. And it does not include transmission losses to get the electricity to a home, which average between 8-14% in the US.

As to wood, efficiency can be all over the board. Wood has a theoretical maximum btu content of about 8,660/lb. That's at 0% moisture and combusted in pure oxygen, obviously not the home situation. For burning wood and using a 20% moisture content for seasoned wood, and 400F stack temperature, wood has an available btu content of about 6,050/lb. When I use 6,050 btu/lb with my Tarm wood gasification boiler, I measure efficiency in transferring btu's to the 1000 gal storage tank at 79%, and because the boiler is in my shop I need to include btu's transferred to the air to heat the shop during the burn. I have measured shop heat loss, and adjusting for the btu's heating the shop during the burn I achieve an 89% efficiency. Efficiency Now, adjusting this for the theoretical maximum of 8,660 btu/lb, efficiency would be 62% of theoretical maximum vs 89% for available btu's.


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