Carbon Footprint of Wood Fired vs Electric

[Deleted user]

Our little pottery studio is wrestling with the idea of a wood fired kiln. Many of our friends use them with great success - but the amount of work and wood is phenomenal. Is it truly the holy grail of firing? 

Luckily, our electrical is hydro here on the Oregon Coast, and quite inexpensive per KW/hr and environmentally low impact (except the salmon!). But there's a lot wood here too! Yet, burning bans exist for a minimum of 3 months in the Summer - and being in the middle of a forest, sparks can be a very scary thing. How could we not fire for 3 months? 

Also, due to the climate change happening in our environment - I think a carbon footprint calculation is in order. Not only for our living, but in our firing to offer to our customers. How many trees did that pot require? How can it be mitigated? Can this footprint be handed off to the end consumer without discussing its environmental impact and mitigation?

With the new control systems available now for maximum efficiency in electric kilns, we can calculate cost per firing. Ramps and off hour peaks can be calculated in for even more efficiency. We just ordered a new Skutt 1027 with their new wi-fi controller, and envirovent system. I am looking forward to the monitoring and calculations it offers.

We spray our glazes, and mix them (sometimes up to 5 different ones) for interesting patinas that can normally only be accomplished in solid fuel kilns. It's a fun attempt at working the electric!

I would love to hear peoples thoughts on the benefits of wood fire vs gas and electric. 

[liambesaw]

Your personal impact on the environment with wood firing is pretty low unless you're chopping down trees specifically to burn.  When we go out and get wood (up here in Washington) we always take fallen trees, which would eventually burn in a forest fire anyway.  But it may be hard to source that amount of dead fall if you're firing very often.  You could mitigate this by building a large kiln and firing periodically instead.  

Gas is very dirty in comparison, it is marketed as clean, but it's only clean burning.  The process of extracting, refining and transporting is where the environment suffers.  

Electric, especially hydro\wind is pretty clean (and CHEAP), and like you said, it's very easy to keep track of the cost.  Hydro does have a pretty negative impact on wildlife, but the amount of energy created is very high, so the environmental cost is low (compared to traditional sources).

 

No matter which you choose to use, your impact is near zero, so choose with your mind and not with your heart.

[Mark C.]

I agree that the carbon footprint  of wood is next to zero compared to hydro.

Wood is a natural deal and as a forestry /art major at one long ago distant time (1971-1972) before I dropped forestry and stayed with art. We learned that trees have a given life cycle and after they mature (called climax forest) they degrade and burning is a natural process for the next one to restart.

Wood kiln do take lots of wood but in your state wood is a harvestable resource that is similar to cutting grass.

I would go for it and yes compared to electric fire wood pots shine more in most values-they are big work to produce so you need lots of help firing.

As to gas well -propane is expensive and I think you are not in a natural gas zone which is way cheaper . I myself love high fire pottery for many reasons but I also have had natural gas kilns for 45 years.

I'm a gas kiln person-I like the fire and the results and the process.

[GEP]

In my area, there is a wood pallet supplier that will give its old worn-out pallets to wood-firers for free. This is wood that has served a long industrial life and is otherwise heading for a landfill, unless a potter gives it one last ride through a wood kiln. Environmentally speaking I think it’s a plus. The pallets need to be busted up, but the wood is already in long flat pieces, and very dry from age.

I personally think that wood-firing is less healthy for you, the potter. After a wood-firing, my lungs and throat feel like I’ve smoked a whole pack of cigarettes.

[Mark C.]

No question wood is harder on a body than other fuels.Just the physical strength needed to process is a lot.I fire my salt kiln with gas and thats harder on one than a normal gas fire because of the spraying salt/fumes and work involved .Wood /salt soda pots should cost more as they are really  a lot more labor.The wood fires I have been involved with even this way back on my property in the 70's kicked my ass. 

[Min]

I wonder what the publics perception is regarding woodfiring? Have times changed so much that customers now frown on wood fired pots? Is a customer going to have a discussion weighing the merits of gas/electric/wood before making a purchase? Don't think so. There is a good article here discussing various firing methods and their CO2 emissions and how to calculate them.

[liambesaw]

3 minutes ago, Min said:

I wonder what the publics perception is regarding woodfiring? Have times changed so much that customers now frown on wood fired pots? Is a customer going to have a discussion weighing the merits of gas/electric/wood before making a purchase? Don't think so. There is a good article here discussing various firing methods and their CO2 emissions and how to calculate them.

Im sure it would freak people out a little bit if you told them how much wood it took, but if someone told me they wood fired some pots I'd probably think something along the lines of wood fired pizza haha

[GEP]

28 minutes ago, Min said:

Have times changed so much that customers now frown on wood fired pots? I

There’s a teeny population of knowledgable customers who appreciate the amount of work involved, and the historical relevance. Most of them are potters who have tried it themselves. It doesn’t necessarily translate to them buying wood-fired pots.

Everybody else doesn’t care. Wood-fired pots can be compelling and desirable, or not. Just like all other pots.

I’ve never heard of anyone frowning on it. Most people, if you take the time to explain it, find it impressive. 

Edit: I should add that it depends on your region. There are regions (eg western North Carolina) where there are a lot more people who appreciate and buy wood-fired pots. 

[Deleted user]

Thanks for your replies!

We have  deep romanticism for a wood fired kiln. Especially the concept of salt firing with gathered beach wood -  dreams of indigenous / localized art! Architecture! Hand built! Engineering! Renee would love to simplify her glazes with a solid fuel ^10, and rely on fire and ash + reduction instead of the crazy chemistry stuff we're doing with the electric at ^6. Its fun, but all the fluxes can get complicated.

However, like Min has mentioned - many customers in our area are very green. (You've heard the rumors about Portland, OR, right? They're true!)  Guaranteed we will get this question often in our demographic, and it needs to be thoroughly researched and done with sustainability in mind. The idea of a per piece footprint would be the holy grail here if we could offer it.

Thank you all for the input and the direction in research it is sending us. That article from Min is a tremendous resource! I'll run some numbers...

 

[terrim8]

Your little wood burning kiln is not like the scene from this article https://www.technologyreview.com/s/611372/china-is-creating-a-huge-carbon-market-but-not-a-particularly-aggressive-one/amp/ .  I know we all have to help but keep things in perspective!

[Russ]

Wood firing doesn't have to use forests of wood and take days to fire.. for example I built a large 80 cubic foot kiln

that fires from dark to cone 11 in 7 hours and uses around 1/2 cord of scrap wood.

[Deleted user]

25 minutes ago, Russ said:

Wood firing doesn't have to use forests of wood and take days to fire.. for example I built a large 80 cubic foot kiln

that fires from dark to cone 11 in 7 hours and uses around 1/2 cord of scrap wood.

Wow! Do you have any photos you can share?

[Mark C.]

I build a Olsen fast fire wood kiln back in the day-small kiln fired fast-melted the fireboxes and roof fell in after 1st fire.Good learning back then. I have no photos-What stands out was a photo of us there guys in our twenties before and after. We where toast-but of course we also did some drinking and whatever as it was 1973.That did not help the all nighter energy-hey stupid kids come to mind.

[Deleted user]

This young kid thing keeps coming up.... a needed part? Being two old ladies in the woods makes that electric kiln look better!

[neilestrick]

If you really want the effects of runny ash, then you have to burn a lot of wood. If you just want heat with a little vapor and a blush of ash, then fast fire kilns with more efficient firebox designs can burn little wood. A simple catenary crossdraft kiln can give you a lot of ash, but still fire quickly. The one I used to fire in grad school took about 13 hours, but went through 3 pickup loads of wood and gave lots of runny ash. You just need to decide what type of effects you're after, and how you want to fire. Anagama, crossdraft, train, bourry box, noborigama, they all work, but give different effects.

You'll also need to check on local building codes to see if you can even have a wood burning kiln where you are. Many municipalities categorize it as open burning, and won't allow it. The smoke from a wood kiln can also be an issue/nuisance to neighbors.

If you're willing to put in the effort, free wood can be found. In grad school we never paid a dime for wood and went through dozens of cords of wood every year. But it's a lot of work to source and collect it. Also keep in mind the amount of space you'll need to store the wood, and the equipment needed to cut and split the wood. Even if you just buy split wood, you'll want a log splitter to take it down to smaller sizes when needed. If you do any sort of tube kiln, you'll need thin slabs for back-stoking, which means you'll need a chainsaw and sawbuck for cutting it. Dealing with wood takes far more time than the actual firing.

[fergusonjeff]

I currently have one of the catenary cross-fire kilns that Neil just mentioned.  I typically fire in about 12-14 hours and can get decent ash.  It also does well with most glazes.  I often sprinkle a little ash mixture (50% ash and 50% neph Sy) on the wet glazed surface for a little extra ask kick-start.

I use predominantly wood scrap from Amish pallet makers a little north of me and scavenged pine.  The wood is free, and if I did not take it they just spread it out in big piles and burn it.

 

 

[Russ]

I built the kiln where the damper, blower and fireboxes were on one side. The chimney is between the fireboxes  and has a heat shield. Air is forced between this heatshield and the chimney brick preheating the air that is channeled to the fireboxes.  At our altitude (6500 ft) the problem is a lack of oxygen and the blower, scavenged from a home forced air furnace, was the remedy.

It's an all hard brick kiln but I've insulated it well with kaowool and other various materials and wrapped it with corrugated roofing material.

 

[neilestrick]

@Russ that's a bit different than what I was talking about. Here's a rough sketch of the one I used to fire. The arch was 6 feet wide and 6 feet tall. Half is for stacking pots, the other half is firebox. You get a lot of ash without too much wood with a large firebox like that. I could get it to temp in 9 hours, then I usually burned wood for another 3-5 hours just to build up ash. I could get pots really drippy with ash that way. I typically burned 3 pickup loads (Nissan pickup, not full size) of wood.

 

[Deleted user]

When calculating the carbon footprint of the firing, I think we should add in the caloric value of human effort!

[fergusonjeff]

The one I fire is exactly like the one in Neil's diagram.  I use about 0.8 cords of waste wood (combination of salvaged barrel, pallet, and lumber scrap) per firing.