Wood vs Natural Gas Cost Comparison
I’ll show you how to work through the calculations for a wood vs natural gas cost comparison to determine if it is cheaper to heat your house with wood or gas. You can follow through with me, or jump to the end to see the results.
We’ll determine the heat that can be realistically recovered from burning a cord of wood, and then determine the equivalent amount of natural gas required to produce the same heat.
First we have to know the efficiency of equipment burning each of the fuels. Wood burning stoves typically vary from 65% to 75%, so I’ll use an efficiency of 70%.
Furnaces that burn natural gas are typically 80% to 97% efficient today. I’ll make the assumption that our furnace is not one of today’s high-efficiency condensing types, which costs more. Non-condensing furnaces are typically 80% to 90% efficient, so we’ll assume our furnace is 85% efficient.
The recoverable heat value of wood varies considerably and depends on the moisture content of the wood as well as the kind of wood. Below are recoverable heat values of various pines based on an average moisture content of 20%. The moisture value can be reached by drying wood for 4 to 6 months prior to burning. The unit is million Btu per cord of wood (mmBtu/cord).
- Jack Pine = 17.1 mmBtu/cord
- Lodgepole Pine = 19.3 mmBtu/cord
- Norway Pine = 17.1 mmBtu/cord
- Yellow Pine = 22 mmBtu/cord
- White Pine = 14.3 mmBtu/cord
- Ponderosa Pine = 15.2 mmBtu/cord
Let’s use an average of 18 mmBtu/cord for the recoverable heat value of our wood. You can find heat values for many other woods here.
Now let’s look into costs. As with the heat content of wood, the cost of a cord of wood can vary considerably, from free to hundreds of dollars. My experience is that is costs somewhere around $150 per cord for cut firewood so I’ll use that cost.
Side note: One cord is a neatly and fairly tight-stacked wood pile measuring 4 feet x 4 feet x 8 feet. That is 128 cubic feet. If you stack wood in a pickup truck with a bed size of 6 feet x 4 feet x 2 feet high, that’s 48 cubic feet. 48 cu.ft. / 128 cu.ft. = .38 cord and .38 cord x $150 = $57. How high wood is stacked in a truck, the size of the bed, how tightly it is stacked, fender wells, etc. can all affect how much wood your truck can hold. Just be careful to avoid getting ripped off when buying wood!
Back to our cost comparison. We have determined that it costs $150 to get 18 mmBtu of heat from wood burned in a wood stove.
Now, let’s determine what natural gas costs – not some number off the charts, but what you and I really pay for it.
Natural gas cost tends to decrease as volume used increases. That is because all the add-ons like taxes, riders, customer charges, consumption charges, etc. become a smaller percentage of the total bill as the quantity of gas used increases. For a residential bill these add-ons are often the majority of the costs on the bill.
As I write this, the natural gas commodity market price has been in a trading range between $3.50 and $4.00 per mmBtu. To convert cost per mmBtu to the cost per thousand cubic feet (mcf) used for most residential bills, multiply $ per mmBtu by 1.023. So $4.00 per mmBtu is equal to $4.09 per mcf. If your bill uses hundred cubic feet (ccf), simply move the decimal one place to the left for the cost, so the price would be $.409 per ccf.
If you only use 2 mcf in a month, assuming a market cost of $4.09/mcf, you might expect your bill to be $8.18 plus some taxes. Well, not exactly – the monthly gas bill for a typical residence is around three times the market cost of gas used. All the add-ons are likely to be more than 200% of the cost of the market price of the gas. I saw a residential bill recently where the monthly usage was 2 mcf and the total cost of the bill was $26.17 – and that is the norm. The gas company must transport the gas from the source to your home, do quality checks, handle billing, maintain the infrastructure, and on and on – so all the added costs are very necessary and legitimate. The takeaway here is that the cost can be deceiving until you look at the details. And keep in mind that this is just an example. Your gas bill will be different depending on where you live, the time of year, current gas markets, etc. And the ratio of fixed costs to natural gas burned will decrease as you burn more gas. Because of all these variables I strongly recommend using your actual bills to determine cost per mcf.
Hint: To keep it simple, take a gas bill for your house for the month you want to compare with wood cost (January for example) and divide the total cost of the bill you paid by the number of mcf burned. That will give you the real cost per mcf for that month.
So let’s be realistic as to the cost of natural gas for heating our homes. 2 mcf being billed at $26.17 is a cost of about $13 per mcf. I’ll use that in comparing wood and natural gas heating costs.
Let’s summarize what we have so far:
Wood – $150/cord and 1 cord = 18 mmBtu
Natural Gas – $13/mcf and 1 mcf = 1.023 mmBtu
These numbers are the actual heat content that can be realized by burning each of the fuels. But the devices used to burn the fuels are not 100% efficient, so we have to derate the mmBtu numbers by the efficiency losses for wood stoves and furnaces.
So for wood stoves, the actual obtainable heat is 18 mmBtu x .70 = 12.6 mmBtu.
And for gas furnaces, the actual obtainable heat is 1.023 mmBtu x .85 = .87 mmBtu.
Now, let’s see how many mmBtu’s of natural gas are equivalent to one cord of wood.
12.6 mmBtu/cord divided by .87 mmBtu/mcf = 14.5 mcf/cord.
And 14.5 mcf/cord x $13/mcf = a natural gas cost of $188.50 for an equivalent cord of wood.
So, based on our assumptions, it costs about $38 more to heat your home with a furnace burning enough natural gas to equal the heat content of 1 cord of wood, as compared with burning 1 cord of wood in a reasonably efficient wood stove.
Keep in mind that 1 cord of wood lasts quite a while and you have to burn a full cord in order to save the $38. For all practical purposes the two fuels cost the same.
Also keep in mind that wood burning pollutes much more than natural gas and requires far more work, namely hauling and stacking the wood, stoking and tending the fire, periodically cleaning the chimney to avoid creosote buildup, and cleaning out the ashes. A furnace gives much more uniform heat in a home and you don’t have to think about smoke and draft issues. It’s hard to beat today’s efficient furnaces burning clean natural gas.
Personally, I would heat with natural gas and use wood stoves for aesthetics and in locations where gas is not available.
I’ve led you through all the details and how the assumptions were made to arrive at this conclusion. You can see how the real costs can easily be twisted by using the market cost of natural gas instead of what we really pay, changing the efficiency of the burning appliances, or assuming a different heat content for the wood being burned. Lots of variables give marketing people room to swing the results any which way they desire. I encourage you to run through the calculations using the numbers unique to your situation. If you have access to free or very low cost firewood, heating with wood becomes a compelling choice.
Wood is a biomass fuel. Learn more about burning wood and other biomass fuels here.
What are your thoughts? Share them below.
I believe storage and transportation of the wood alone “burns up” $38 in a snap. I’ve observed my wood burning neighbors do 2 or 3 wood runs 3 hours north in V8 pick up trucks (6 hours total) …plus loading and unloading. Insulated once and enjoy the thermostat!
I want you to remember this comment when you don’t have power to run that hot forced air furnace.
Well in most places, a permit to cut 5 cords of wood is $20. Plus the fuel cost, Wich in my case is not to far away. So do the math. And in one season you will burn closer to two cords if the winters are not very intense. I will never trade a wood burning stove for any type of gas or electric furnace. Plus, the heat from a wood stove just feels so much better.
Where are you that you require a permit? I burned 6 cords last year and still relied on gas (sk)
No one burns pine its not safe builds up byptoduct and can cause chimney fire should have used oak for calculation also most buy wood by face cord 8×4 ft by 16 to 18 in deep noy by the pick up truck load
Nothing wrong with pine as long as it’s dry like everything else. Lots of people complain about it but there’s nothing wrong with it
Enjoyable read and interesting topic, however one glaring mistake in calculation ruins the whole article. As stated above, no one that heats with a woodstove uses pine. I use oak and its has 2X! the energy content (BTU) compare to pine. It would be worth your time to run calculations again with a more realistic standard.
Stevie – burning oak does indeed release more heat than pine. Bur oak is about 26 mmBTUs, Gambel oak is about 31 mmBTUs, Red oak is about 25 mmBTUs, and White oak is about 29 mmBTUs. The problem is that much of the country cannot burn hardwoods, either because it costs too much, or because it simply isn’t available. Since you have access to good oak to burn, consider yourself very fortunate. Many people burn pine because it is affordable and plentiful.
I use pine and there’s nothing wrong with it
It’s been a long time I actually pulled out a piece of paper to take notes on a blog post. Thanks for this. You’ve earned yourself a new reader!
Now I have read that any pine if seasoned properly does not have the risk as stated above. Also if your are burning hot enough as any sweeper will tell you, your creosote build up is minimal. Proper and regular maintenance of the system also prevents that. So confirming these points with data would be of great benefit as well. thanks for the info
Thank you for your comment Kurt. You are correct that creosote buildup can be greatly reduced by following a few simple rules. I added a link that explains the problem of creosote buildup and provides a list of ways to avoid it.
Two things, no one here burns pine. Pine has very low heat content. Most people here burn maple, beech, or some other hardwood. The heat value of those woods is far superior to pine. Also your wood cost is high for this area. It seems to me that you are trying to discourage the use of wood for heating homes. Also the cost of natural gas may double or triple this winter making wood far cheaper.
I burn pine so lay off. The next best thing here is poplar so lay off dude
Interesting comment you made, “wood burning pollutes more than natural gas”. Wood is carbon neutral. The carbon released from burning equals the carbon absorbed by growth.
On the cost side, even without a price increase in natural gas by 2030 the taxes will increase price five fold.
Good observation Mark. Burning wood is indeed carbon neutral if the entire lifecycle is taken into account. In rural areas where the population is sparse, wood-burning is a great way to heat. However, there are some other considerations that should be kept in mind. Here is an article from Smithsonian Magazine that talks about some of those considerations: Wood burning is carbon neutral
Thanks for this. I’m trying to decide whether to install a gas line and a gas fireplace (gas furnace is not really an option) or a wood burning stove. I’m just haha too confused by this post and can’t really figure it out. I do appreciate your responses in the comments and reading the comments.
A local gas company gave me their price in therms: As of Jan 2022, $0.65/therm = 100,000BTU I think.
It would be so helpful if you had at teh top: “Gas is approximately X per mmBTU and wood is approximately Y per mmBTU.” That would be really helpful. Or also a short equation at top where you can input the mmBTU rate for different wood cords, and I can find my own cost per cord, and then enter my own cost per Therm (or if there is a standard way gas companies share their prices, I guess you said mcf), and then I can much more easily compare those prices – I just have to find out my local cost per therm or mcf, and my local cost for a cord of a certain kind of wood.
What do you think?
To compare the cost of heating for your particular situation, try going through the calculations step by step. I think you’ll find it works if you take it a step at a time. Also, keep in mind that there are a lot of considerations other than cost.
It’s too bad a gas heater is not an option. That would probably be the cleanest and best choice if you could install one.
Some considerations:
If your goal is heating and you go with wood, a wood stove will typically provide more heat than a fireplace. Many people that heat with wood choose it because they can get it cheap, or in many cases, for free. And, of course, hardwood is far better than a soft wood like pine.
Think long-term. Will you have a sufficient source of wood into the future? Will the price remain low enough to justify using it? Are you ok with stoking the fire to keep your place warm day and night? Are you ok with cleaning the chimney each year?
For less hassle or if environmental concerns are high on your priority list, then gas is a far better choice than wood.
Good points. Thank you for your excellent reply. See comment (awaiting moderation) about all the other fees I’ve discovered for having gas. I wonder if propane or something else is an option. The gas fees are just too much for us.
Jesse – I use propane for the kitchen oven/stove in our house. Our house is all-electric and natural gas isn’t available, so propane is the next best choice. A tank of propane lasts a long time when only used for the stove – I fill mine once a year. And there are no ongoing costs except filling the tanks as needed. You can either have the propane truck come to you, or do like I do and just carry the tanks to Costco to get them filled.
Two things to keep in mind about using propane: 1) You have the initial cost of running a gas line to your stove from outdoors, and 2) propane provides fewer BTUs/cu.ft. than natural gas. Because of the different BTU value, the stove needs to have different orifices for burners than a natural gas stove. But it’s easy to change out orifices and I cannot tell any difference between cooking with natural gas or with propane.
So propane is definitely an option for you, both for heating and for cooking.
Important addition to this conversation, if it’s not in here already. I live in Atlanta, GA. I want to add gas to our electric home simply to cook with gas, and possibly for some supplemental heat with a gas fireplace – maybe eventually a gas furnace (our house is cold!).
Well, I’m learning now that the gas for cooking would be like less than $5 month – or something low, while there are TONS of other fees!! So, in case anyone was wondering, having gas for some small things is not worth it. There’s a $10 monthly customer service fee from Gas South, then $20 monthly pass through fee from Atlanta Gas Light (who owns the pipes underground), finally in the winter a $25 seasonal fee!!!. In our case, using wood for supplemental heating makes LOADS more sense (sorry environment) than paying tons of fees all year round and not using much gas.
Jesse, thanks for your great article. We are just wrapping up a big renovation at our (30-year old) cottage that was heated by electric baseboards, and a wood stove for secondary heat. With the ever-increasing cost of hydro in our region I decided to invest in a furnace. Because we are in (remote) cottage country, the only option is to install a propane furnace. When it came time to re-think the wood stove we were wrestling between a propane fireplace, or an energy-efficient, wood-burning fireplace. But after 30-years of slogging firewood around, the appeal of hitting the ON button on the fireplace remote, was too compelling, and we chose propane.
However… when it came to choose a fireplace for our new (40’x14′) 3-season porch, the snap-crackle-pop, aroma, and coziness that is only available from a real fire made the choice easy. Plus, the high-efficiency fireplace we purchased generates up to 99,000 BTUs from cord wood. Our indoor propane fireplace can’t produce anywhere near these BTUs. So, in summary – one of each is an ideal world!
Jesse, for this article, did you ever run the numbers comparing the cost of natural gas vs. wood – to propane vs. wood? I saw your comment in one of the blog comments where you responded how natural gas provides higher BTUs, so is it safe to assume the spread ($38) would be your much greater?
And would it change your conclusion that wood and natural gas are basically a draw, if it was propane instead of natural gas?
Thanks!
An excellent article.An important omission about the bigger picture —Wood heating is a therapeutic and physiological activity for many of us.
When the big questions in life are faced and you admit the “make work” aspect ,the “manly” need for a truck,the pride and satisfaction of maintaining and operating your chainsaw,getting out into the woods,the strong feeling of self- sufficiency ,exercise ,and on and on.
Any city slicker can order dry,split ,delivered firewood.Minimal economic benefit and possible some fireplace aesthetic benifits ,but that’s not the deal. Country Boy.