Wood-Fired Electricity?

[oppermancjo]

I can't seem to locate a thread with any kind of discussion and I don't recall seeing this brought up. I'm still researching what kind of furnace or OWB to go with in the house. This morning, the thought occurred to me, "what about a generator?" A quick Google search brought up a few results for wood-fired generators. By the looks of it, there are a few options available.

I'm wondering if any of you guys have any input or experience? Anybody have a setup like that already? I'd be interested to learn about it. My current electricity costs probably average $100/month or $1200/year. I can't seem to find any good pricing at the moment to find out if it's worthwhile and how long it would take to pay for itself. Are there setups that will cover my entire power usage or is that asking too much? Maybe cover half? On a side note, I have an electric hot water heater so by installing a loop to heat that with wood off of either the IWB or OWB, I'm guessing would reduce my electric costs by maybe 40% without having to mess with a wood-fired generator. The water heater isn't super old but it's not cutting edge either.

Are there battery storage options? How long do they last before needing to be replaced and what's their cost? My thoughts on that are similar to people that bought a Chevy Volt and are saving all this money on gas but then have to spend a few thousand dollars to replace the batteries after 3 or 4 years...

Lots of questions and I'm not finding a ton of answers at the moment.

Very curious to see if anyone has thoughts or experience.

Thanks!

 

[Patrick62]

Ideas a plenty

It would take a LOT of wood, and the conversion process of wood to electrical either isn't efficient, or has some hazards. You would think that eventually there would be a thermocouple setup where you could pass heat thru it and cold on the other side to make power.. but to make a large enough one to power a house is going to be.... unoptanium.

Next obvious setup is a boiler and steam generator. If a fella was on call the entire time it was operating it is workable. It would use a LOT of wood. Other ideas would be some kind of a sterling cycle engine but the efficiency is pretty low unless very high tech. You might be able to get a few watts this way.

The warm reality (not the cold one?) is heat your house, plumb in your water tank. And pay the electric bill. If you want to life like those of us (including me) who are "off the grid" Get some good batteries, large solar panel, maybe add a wind turbine, a nice inverter to run the house with. you then have to adjust your consumption to what you are generating. Not a bad idea to have a small gas powered genny for backup or really heavy loads.

 

[oppermancjo]

Thanks, Patrick. That's what my gut feeling was but figured it was worth investigating. I've thought about solar before. During the summer, my house gets direct sunlight for about half the day at best as I am pretty much "in the woods." Not sure if that would generate enough power to justify the cost. Perhaps over the long run. Same deal with a wind turbine. Being surrounded by 100ft+ tall trees, I don't get a lot of wind at the house.

 

[jthornton]

What about a wood gas powered ICE turning a generator as a backup to solar? They drove wood gas powered cars during WW2 in Europe IIRC.

John

 

[Mac88]

Do a web search for "gasifier". As jthornton mentioned, they were used extensively during WWII and before. You can even get plans from FEMA on how to build one. UTube videos galore. You could no doubt run a portable generator that way, but I'm not sure how stable the output would be.

 

[mooseracing]

If you search for TEGs or Thermoelectric there a few different ones out there. I've looked at some smaller ones just so I could recharge or power some small things during outages in the winter.

 

[Chris-PA]

I have considered making a TEG for the woodstove, and I still may if I can find the time, but this is low output power and will require a good cold heat sink as well as the heat from the stove.

The best bet would be a stirling engine of some type running a generator.

 

[Naked Arborist]

I spent some time last year researching gas a fires. It good tec and they can be made efficient if you keep them small and tall. You need two for cleanings and down time if it occurs.
The best part is if you have the wood they will make a ton of gas. The hardest part is keeping the fly ash out of the gas stream. The filters are maintenance intensive. You have to use bone dry wood or the efficiency is knocked way down and creosote gets out of control. A good masonry one like a Russian heater is the way to go for home based ground units.

I would think a steam gen unit would be needed for HO during peak use.

An old motor of any kind, wood chips and a couple of 55 gallon drums. You still need to make scrubbers and a firing chamber. Feeding a gasifier to an engine with an attached gen seems to be the least costly and most dependable. If you get the syn gas hot enough you can crack the water in to hho2. Most time you need electric for that not just heat.

 

[Hddnis]

Using firewood to get electric power is possible, but more expensive than buying the power, both in money and time. For the short term get a set up to heat your water, woodstove in the winter and solar in the summer. That will take a big bite out of your power bill and can cost as little or as much as you want to spend.


I recently watched a not very well edited but very informative video on youtube, whereis a guy is fueling a set up with wood chips and out of it he gets heat, runs a generator on syngas, gets methonal, gasoline, diesel, and propane to run a propane fridge.

It is one of those dream set-ups, kind of a utopia for independant living with all the modern stuff thrown in.

Reality is that his system would need constant babysitting, he has to be there to run it. It would also vary a little from batch to batch. A great idea though overall.

My long term goal it to have a set up like his, mounted on a trailer, partial computer control, ready to pull out and fire up. I'd play with it on weekends, have it around for emergencies, but basically a hobby.

In the mean time my goal is like I mentioned above, use the firewood to heat water in the winter and then solar in the summer. My next goal it to get my well pump on a solar set up, payback time is less than three years for a system dedicated just to the pumping water, and it will keep working when the power is out.

So, in summary, the sky is the limit, the internet is a goldmine of information just waiting for you to research it. Run the numbers, start small, figure out what works for you and then come tell us about it. (with pictures)



Mr. HE

 

[zogger]

Wood to electricity is expensive and involved. small steam boilers with the turbine and generator setup, etc, have to be custom made, I dont think there are any plug and play units out there, not small house sized units. And they have to be watched. I worked a big woodshop that was setup to do that, full time firemen/boiler operators to run the things, every shift.

Heating your hot water and dropping your largest electric demand is much more practical with your OWB or similar wood gear. As the others said, next easiest to acquire and install and use is solar PV or a fuel genny. Too many trees in the way, hey, more firewood! hehehe

The gasification units as pointed out are doable, but operator intensive. Yes, you can go that way, good luck!

I lived with solar PV almost 5 years, and once setup, maintenance is joke level minimal, top the batteries off with distilled water (and you can make your own distilled water with a separate solar rig), adjust the array seasonally, by changing the angle, although those can be automated (using self powered tracker), it only takes ten minutes to do once every three months. Or once a month, your choice.

alternate energy in general, I suggest checking out homepower online.

Renewable Energy & Efficiency Technologies | Home Power Magazine

 

[cat10ken]

The easiest way to turn firewood into electricity is to sell a cord of wood every month to pay for your electric usage. That simple act will save you a ton of money and hassle.

 

[dave_dj1]

You can power an internal engine with wood gas. In turn you could power a generator.
It's not all that complicated of a set up, just looks to be very time consuming as stated earlier.
Interesting non the less.
Use a Wood Gas Generator to Power Your Truck

 

[Hddnis]

"Wood" fired stove that produces electricity.

We Tried It: BioLite CampStove Roasts Marshmallows While Charging Your Cellphone | Fox News Magazine



Mr. HE

 

[woodchuck357]

Electric water heater is the most efficent use of electric heat

and the electric water heater can be insulated very well. Gas water heaters can't be insulated therfore are good only for almost continous use, the instant the flame goes out the heat in the water in the gas fired heater is lost up the flue.

Gas water heaters can easily be converted to wood by removing the burner and enlarging the firebox. I have converted many scrapyard gas heaters for camp use. I have one in the basement set up in line with the electric one with shut-offs so it can be used as needed or left out of the system when I don't want to mess with it.

The gasifier-generator system is the most practical way to convert wood heat to electric energy. The wood chippers could provide a cheap supply of fuel instead of dumping in a land fill. The wood doesn't need to be any drier than firewood.

 

[OH_Varmntr]

Thermocouple-charged automotive batteries.

There is research and development going on now in the diesel industry that uses banks of thermocouples installed in the catalytic converter of the diesel exhaust stream to generate electricity to charge the battery.

With much emphasis on efficiency these days, they are trying to figure out ways to lessen the load on an engine. Believe it or not, automotive alternators need quite a bit of power to generate around 120DC Amps. By lessening the load on the alternator, more power is available from the engine for the drivetrain, so things become more efficient.

With gasification boilers becoming more the norm these days, I would think someone would be able to harness the extreme heat generated by the process to perform similar functions as the automotive application does. Thermocouples do not absorb much heat, so you wouldn't need to be worried about making your burner less efficient.

The only issue to overcome is the need for many many thermocouples because they generate minimal DC amps. The other problem is with DC power due the need to store and invert it to AC power to be utilized in the home. While being able to store the power in chemical form (batteries) seems neat, the initial cost of the batteries and inverter system would be substantial to most. Plus, batteries do not last forever, so you'd need to maintain and replace them eventually.

I've been pondering the idea for a while now.

Another idea is installing a small turbine in the flue of the wood burner. It would harness the heat energy and airflow to spin a small generator. Basically like a turbocharger in a vehicle.

 

[Hddnis]

Regarding thermocouples, I remember reading a website for a company that does R&D in that area, mostly building micro devices that generate power from temperature differentials for remote monitoring, such as temp sensors on a pipeline that transmit to a central computer. They have a prototype for a diesel truck exhaust that generates 1200 watts, mostly taking over the electrical loads. It is nothing more than a bank of small thermocouples such as the type that are readily available from Taiwan for cheap.

Another item they developed was a self-powering pellet stove, which is a very good idea. When I had a pellet stove I'd spend almost $45 a month on electricity to run it. Add in about that much in pellets and my heating bill was $90 a month. It was still a huge savings because running the electric furnace could hit $300 a month, but it sure seemed like a lot to spend.



Mr. HE

 

[zogger]

There is research and development going on now in the diesel industry that uses banks of thermocouples installed in the catalytic converter of the diesel exhaust stream to generate electricity to charge the battery.

With much emphasis on efficiency these days, they are trying to figure out ways to lessen the load on an engine. Believe it or not, automotive alternators need quite a bit of power to generate around 120DC Amps. By lessening the load on the alternator, more power is available from the engine for the drivetrain, so things become more efficient.

With gasification boilers becoming more the norm these days, I would think someone would be able to harness the extreme heat generated by the process to perform similar functions as the automotive application does. Thermocouples do not absorb much heat, so you wouldn't need to be worried about making your burner less efficient.

The only issue to overcome is the need for many many thermocouples because they generate minimal DC amps. The other problem is with DC power due the need to store and invert it to AC power to be utilized in the home. While being able to store the power in chemical form (batteries) seems neat, the initial cost of the batteries and inverter system would be substantial to most. Plus, batteries do not last forever, so you'd need to maintain and replace them eventually.

I've been pondering the idea for a while now.

Another idea is installing a small turbine in the flue of the wood burner. It would harness the heat energy and airflow to spin a small generator. Basically like a turbocharger in a vehicle.

Thermocouples are neat. I used to work for a farmer who had an oil lamp with a thermocouple on it that also ran a radio from the waste heat. He got it in russia during ww2 when he was in the merchant marine.

With that said, I would think a stirling cycle engine would work better as a generator, if one could actually source an affordable one of the correct size. Doesnt seem to exist though, I have looked...

I have NO idea why stirlings are not in day to day common usage all over. Seems a spiffy design and a thousand uses out there in cogeneration scenarios, from small to whopper. Just must be too difficult and expensive in that area between small scale model and huge expensive big commercial systems.

Perhaps thermocouples can step in, there sure is a big potential market out there!

quick google found this

TEG Power Thermoelectric Generators & Seebeck modules daisy chain a buncha those guys...

Here is a wood to steam genny page

Home

I just found these, no idea how reliable or anything like that the companies are. The steam unit has an actual OMG price connected to it.

For the time being, my simple little solar array will have to do the job for long term minimal backup power. I have a gas genny, but it is sorta stupid, it was just cheap to buy used and it works. I would rather either a propane one or diesel, as we have mass quantities of that on hand all the time. Wood fired anything would be nice, but the costs appear to be simply outrageous for anything on the market at a single home sized range that might be turnkey. A DIY wood gasifier/ gas generator conversion looks to be the easiest (well cheapest, not easiest) solution.

Here is a commercial home sized unit, again, at OMG pricing

Personal Energy Grid | Victory Gasworks: Woodgas Generator, Turn-key Home Solar Power, CHP Natural Gas Generators, Gasifier, Biomass Energy

I know solar PV was finally down to a buck a watt for panels (and looking to get cheaper still real fast) until last year, when some apparent lobbying action got tariffs applied to the asian suppliers, primarily china.

 

[OH_Varmntr]

Regarding thermocouples, I remember reading a website for a company that does R&D in that area, mostly building micro devices that generate power from temperature differentials for remote monitoring, such as temp sensors on a pipeline that transmit to a central computer. They have a prototype for a diesel truck exhaust that generates 1200 watts, mostly taking over the electrical loads. It is nothing more than a bank of small thermocouples such as the type that are readily available from Taiwan for cheap.

Another item they developed was a self-powering pellet stove, which is a very good idea. When I had a pellet stove I'd spend almost $45 a month on electricity to run it. Add in about that much in pellets and my heating bill was $90 a month. It was still a huge savings because running the electric furnace could hit $300 a month, but it sure seemed like a lot to spend.



Mr. HE

I'm a apprentice electrician for a steel mill and we use thermocouples for monitoring temperatures in our 2 furnaces, one which runs about 2200*F and the other about 2800*F. We also use T/Cs for monitoring the temps of a variety of other equipment so I'm quite familiar with them.

1200 watts from a 12VDC system equates to roughly 100DC Amps. DC and AC power is not equal, so when you invert DC to AC you lose some power through inverter efficiency. Either way, that rating is from a bank of T/Cs that must be packed into a relatively small catalytic converter. Doubling or tripling the amount of T/Cs used can yield quite a bit of power available for use.

But that power is available at certain temperatures, and since gassification wood burners don't burn constantly, available power will vary. That's where batteries come in to absorb the extra power not being used and to make up for the lack of power available when more is needed.

If they were more efficient and cheaper, I'd buy some and try it myself. However, like most technology, the longer it is available the cheaper it becomes.

Thermocouples are neat. I used to work for a farmer who had an oil lamp with a thermocouple on it that also ran a radio from the waste heat. He got it in russia during ww2 when he was in the merchant marine.

With that said, I would think a stirling cycle engine would work better as a generator, if one could actually source an affordable one of the correct size. Doesnt seem to exist though, I have looked...

I have NO idea why stirlings are not in day to day common usage all over. Seems a spiffy design and a thousand uses out there in cogeneration scenarios, from small to whopper. Just must be too difficult and expensive in that area between small scale model and huge expensive big commercial systems.

Perhaps thermocouples can step in, there sure is a big potential market out there!

quick google found this

TEG Power Thermoelectric Generators & Seebeck modules daisy chain a buncha those guys...

Here is a wood to steam genny page

Home

I just found these, no idea how reliable or anything like that the companies are. The steam unit has an actual OMG price connected to it.

For the time being, my simple little solar array will have to do the job for long term minimal backup power. I have a gas genny, but it is sorta stupid, it was just cheap to buy used and it works. I would rather either a propane one or diesel, as we have mass quantities of that on hand all the time. Wood fired anything would be nice, but the costs appear to be simply outrageous for anything on the market at a single home sized range that might be turnkey. A DIY wood gasifier/ gas generator conversion looks to be the easiest (well cheapest, not easiest) solution.

Here is a commercial home sized unit, again, at OMG pricing

Personal Energy Grid | Victory Gasworks: Woodgas Generator, Turn-key Home Solar Power, CHP Natural Gas Generators, Gasifier, Biomass Energy

I know solar PV was finally down to a buck a watt for panels (and looking to get cheaper still real fast) until last year, when some apparent lobbying action got tariffs applied to the asian suppliers, primarily china.

Thank you for the research materials.

 

[woodman6666]

I have studied this extensively and at this time I have nothing feasible to make electricity from firewood. I have spoke with the guy who runs the gasifier pickups and they work but are far to troublesome for me to mess with and its basically the same with gasifier generators, neat to mess with but really not practical for everyday use unless you like babysitting. The stirling engine looks ok but the price makes it not even close to a good investment. I agree with whoever said to heat your house and hot water heaters with wood boiler and sell a cord or two to pay your electric bill for now. I do however think that in my lifetime there will be something that will make sense for this I just dont know when that might happen. I will say that it is frusterating paying the kind of electric bills that we do and having a huge OWB and an unlimited supply of free wood.

 

[K2Orion]

Another idea is installing a small turbine in the flue of the wood burner. It would harness the heat energy and airflow to spin a small generator. Basically like a turbocharger in a vehicle.

This thought crossed my mind the other day while contemplating this subject. I ASSume it won't work or I would have heard of it. But it seems like it might be possible?