# Steam vs Gasifier



## th_Wolverine (Apr 15, 2013)

I was looking into concepts for recharging battery banks to go off grid. Unfortunately there is not enough constant wind to use in my area of TN, nor do I get enough year round sunlight to go solar. BUT I have lots of wood in my area and I hope to be able to setup a wood-lot to keep a renewable source of heating fuel for my cabin once I get my property bought. 

So i've been looking up different generator systems used to recharge battery banks in DIY off grid system, and I've found two systems that caught my eye

1. Steam engine: time tested to work to run engines, an example is shown in this youtube video
[ame]https://www.youtube.com/watch?v=CK1P2cwEYZo[/ame]

2. Gasifier: I've read some mother earth news articles about this system that has been used to run a car and I watched a show on TV where they built one to run an alternator and charge a battery bank. 

So what is more efficient a method to use for a DIY self sustaining wood-as-fuel generator?


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## TnAndy (Sep 15, 2005)

th_Wolverine said:


> I was looking into concepts for recharging battery banks to go off grid. Unfortunately there is not enough constant wind to use in my area of TN, nor do I get enough year round sunlight to go solar.


What do you mean you don't have enough year round sun to go solar ?

You're down in middle-west TN and get a more than I do between mountains up here in east TN, (5-6 hour sun 'window' between ridges) and I generate all the solar I need. Unless you're limited by some factor like you're stuck with a very small lot tucked into the north facing side of a hill, you get plenty of sun there....trust me.










Using wood, either for steam or wood gas is a way one could supplement solar, but I sure wouldn't want to depend on it for constant use. WAY to maintenance intensive for one thing, and WAY WAY too fuel intensive for the other. You'd spend 1/2 your days cutting wood, feeding a burner and doing the maintenance to keep it running. With solar, you put it up and pretty much forget it, except to run some backup when the weather is crappy for an extended period.


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## ||Downhome|| (Jan 12, 2009)

If your just past research, go with the gassifier out of the two options.

Less learning curve.

Steams a great thing but really not something a beginner wants to jump right into and depend on.

I also have been under the impression any time you can remove a step from a process it becomes that more efficient.

Steams also take special equipment, thats not inexpensive, with wood gas a properly designed gassifier you can pretty much fuel any ICE.

That weed whip engine on steam or compressed air is cool but its got no real torque. 

A Ice running on wood gas only as a general rule will give you half horse power.

I think that can be Improved with proper cooling of the gas though. 

Either type of engine will have inherent losses, both due to heat.

With a liquid cooled ICE you can recoup some of that loss by reclaiming the heat, you can also harvest the heat from the gas cooling.

One draw back to the gassifier is having small enough feed stock to keep it fed, so a 4' dia log would not be a wind fall. but a chipper and the brush from such a tree,as well as wood shop scraps and saw dust would be.


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## th_Wolverine (Apr 15, 2013)

TnAndy said:


> What do you mean you don't have enough year round sun to go solar ?
> 
> You're down in middle-west TN and get a more than I do between mountains up here in east TN, (5-6 hour sun 'window' between ridges) and I generate all the solar I need. Unless you're limited by some factor like you're stuck with a very small lot tucked into the north facing side of a hill, you get plenty of sun there....trust me.


That's very interesting, I guess all the farmers around here haven't looked into it very much because most of them think we don't have enough for year round generation. We're always super overcast most of the winter and have a ton of (as winnie the poo would say) "blustery" days in late spring, so I always just assumed I wouldn't have enough sunlight to do a homesteading cabin and a few workshops off of it. I love the pictures, do you have a certain setup plan or kit you used or did you just figure it out for yourself?



TnAndy said:


> Using wood, either for steam or wood gas is a way one could supplement solar, but I sure wouldn't want to depend on it for constant use. WAY to maintenance intensive for one thing, and WAY WAY too fuel intensive for the other. You'd spend 1/2 your days cutting wood, feeding a burner and doing the maintenance to keep it running. With solar, you put it up and pretty much forget it, except to run some backup when the weather is crappy for an extended period.


So steam or a gasifier could be a decent backup plan in the winter as long as I go ahead and cut extra wood specifically for that purpose you think? I litterally know squat about how electrical systems run when you are going off grid any good online articles to look out for?


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## Jim-mi (May 15, 2002)

Live steam is inherently very dangerous and requires full time attention.
Yes you can dig up utube video's of very small "units" that will produce a tiny amount of power . . . . .But the larger the rigs---meaning more usable power--the danger factor really jumps up.
Ask your self if you want to spend all your day tending a steam rig . .??

If either live steam or gasifier's were really good options some entrepreneur long ago would have developed some home sized units . . . They have Not......

As I type this my home is being powered by Solar panels . . . .and in between the clouds I filled up the big water holding tank . . .Solar powered deep well 240vac pump...

Need to go turn on the water for the tomatoes--again---


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## ||Downhome|| (Jan 12, 2009)

There are people producing home sized gassifier units Jim-mi, as well as kits.

But most people that know and are interested in gassification have the skills, tools to build their own.

Rather then spend a few grand on a ready made or kit option.

Its not rocket science... even the crude FEMA plans will do in a pinch.

Steam is a expensive hobby. 
Its also more complicated and as you point out can be dangerous.


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## TnAndy (Sep 15, 2005)

th_Wolverine said:


> That's very interesting, I guess all the farmers around here haven't looked into it very much because most of them think we don't have enough for year round generation. We're always super overcast most of the winter and have a ton of (as winnie the poo would say) "blustery" days in late spring, so I always just assumed I wouldn't have enough sunlight to do a homesteading cabin and a few workshops off of it. I love the pictures, do you have a certain setup plan or kit you used or did you just figure it out for yourself ?


Well, then those farmers have missed the boat. 

For one thing, there WAS ( don't know if it's still there ) a 25% rebate/tax credit/something thru USDA specifically for farm solar. Combine that with the 30% federal energy credit and 55% of the dang system was paid for by Uncle Sammy.

THEN, TVA ( I assume TVA is your power supplier ) had a deal where they paid 12 cents OVER retail for all solar produced, but I think that is down now to 6 cents ( still not a bad deal )




th_Wolverine said:


> So steam or a gasifier could be a decent backup plan in the winter as long as I go ahead and cut extra wood specifically for that purpose you think?


I think you'll still be cutting a lot of wood.


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## wy_white_wolf (Oct 14, 2004)

PVWatts actually shows pretty good insolation for Nashville. I don't see where you'd that much different then them.

"Station Identification"
"City:","Nashville"
"State:","Tennessee"
"Lat (deg N):", 36.12
"Long (deg W):", 86.68
"Elev (m): ", 180
"PV System Specifications"
"DC Rating:"," 1.0 kW"
"DC to AC Derate Factor:"," 0.770"
"AC Rating:"," 0.8 kW"
"Array Type: Fixed Tilt"
"Array Tilt:"," 36.1"
"Array Azimuth:","180.0"

"Energy Specifications"
"Cost of Electricity:"," 6.9 cents/kWh"

"Results"
"Month", "Solar Radiation (kWh/m^2/day)", "AC Energy (kWh)", "Energy Value ($)"
1, 3.62, 87, 6.00
2, 4.32, 93, 6.42
3, 5.25, 121, 8.35
4, 5.53, 117, 8.07
5, 5.63, 121, 8.35
6, 5.95, 121, 8.35
7, 5.99, 124, 8.56
8, 5.68, 119, 8.21
9, 5.27, 108, 7.45
10, 5.07, 111, 7.66
11, 3.63, 80, 5.52
12, 3.22, 74, 5.11
"Year", 4.93, 1278, 88.18

WWW


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## buenijo (Jun 14, 2012)

th_Wolverine said:


> I was looking into concepts for recharging battery banks to go off grid... BUT I have lots of wood in my area and I hope to be able to setup a wood-lot to keep a renewable source of heating fuel for my cabin once I get my property bought...
> 
> So what is more efficient a method to use for a DIY self sustaining wood-as-fuel generator?


 Short answer: gasifier

Long answer: It depends. The main problem with a wood gas engine system is the fuel processing. The larger the gasifier, then the less fuel processing required. However, a large gasifier implies a large engine and charging system. This, in turn, implies a large battery. I think it can be practical if electricity loads are very low. A large battery could be bulk charged as required by running the gasifier/engine system - heat from the system might be harvested during the run as well. The most efficient configuration I have seen was devised by Ken Boak of the UK. You can find his system with google (use "Ken Boak Lister powercubes gasifier" as search terms). What he does is operate a wood gas engine system daily to generate AC power at a constant fairly high rate of about 2500-3000 watts. The battery is charged and the heat from the engine is harvested and stored. Two major problems are presented: (1) the fuel processing mentioned before (making wood chips and small chunks is a pain), and (2) the system has to be loaded down to high levels to pull air through at a sufficient rate and keep temperatures up. It's not easy to find ways to use 3 KWe in a modest off grid home. Mr. Boak uses literally most of the electricity in electric space heaters while the engine is operating just to keep the generator loaded. 

The main problem with steam is the lack of hardware. Also, even if you find it, there is generally only old technology available that is not suitable. You would have to develop a system to make it worthwhile, and this is beyond most people's inclination, knowledge, or pocketbook. However, I think a good system could be devised with a compound steam engine or bump valve uniflow and small monotube steam generator (a modest steam engine can be powered by a surprisingly compact and simple steam generator using a single length of tubing). A system devised to use wood splits (i.e. firewood) could be done, and this alleviates the fuel processing problem. Also, it's possible to design the system for low power and very low speeds so that it can operated for long periods to deliver heat and power at a rate closely matched by the demands in the home. In principle, this could dramatically reduce battery requirements and battery discharge. The system would also be very quiet. Also, harvesting heat from the system would be straightforward since all the heat is available in the steam exhausted from the engine. A small steam engine is generally NOT efficient at converting heat to shaft work, but there is a large room for improvement over the old and primitive designs. Still, getting anything over 10% would start to be difficult for a small steam engine. Whereas, a wood gas engine system used by Mr. Boak is approaching 20% at optimal output. Of course, he's using most of the work for heating applications, so a small steam engine at half the efficiency can make sense where heat is the primary desired product and with the other benefits.

In my opinion, if wood to electricity is desired only for backup power and primarily electricity, then a wood gas engine system is the way to go. If someone wants to finally become totally energy self sufficient, has the wood, and lives in a cold climate with low solar insolation, then a properly designed small steam engine system seems pretty awesome. Unfortunately, it will take a lot of work to finally get a good system up and running well.


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## buenijo (Jun 14, 2012)

Wolverine, I was really just addressing the original questions you posted. Using wood for power generation is fascinating, but photovoltaics is the practical alternative in the off grid setting. The price and quality for PV hardware is very good today and likely only to get better. I suggest going PV with a good but modest battery (go with more panels vs. larger battery since panels are so much cheaper today). For backup power, go with a small generator. For heating applications wood is the way to go.


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## simi-steading (Sep 27, 2012)

One problem not mentioned about playing with steam.. Depending on your state or locality, you may have to have permits... which could also mean getting licensed to play.. everywhere is different. Depends on how it's fired, how large it is, and so on... Looking into the regulations may save you time even thinking about it..

We're not talking about boiling water on the stove to be able to generate enough electricity to be worth the effort.. You're talking about serious stuff, even for a small home system... It can and will hurt you fast..


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## buenijo (Jun 14, 2012)

simi-steading said:


> One Depending on your state or locality, you may have to have permits... which could also mean getting licensed to play.. everywhere is different. Depends on how it's fired, how large it is, and so on... Looking into the regulations may save you time even thinking about it..
> 
> We're not talking about boiling water on the stove to be able to generate enough electricity to be worth the effort.. You're talking about serious stuff, even for a small home system... It can and will hurt you fast..


 Good points. Still, I'm pretty sure a monotube steam generator has no licensing or inspection requirements. About 50 feet of 1/4" tubing is about right for one shaft hp, and an efficient engine design might squeeze out 2 hp. There would be no danger of explosion. Of course, there is always a burn hazard with a poor design, and superheated steam is nasty. 

Basically, I looked into it a great deal, and I have a particular interest since I was once a steam plant operator (power generation). Still, I don't think it's a practical alternative, generally speaking. However, if someone were dead set on it, then in my opinion the way to go is with a one or two cylinder single acting bump valve uniflow piston expander used to direct drive an efficient three phase permanent magnet alternator for direct battery charging via a bridge rectifier. Keep output under 1 KW as this will make for a smaller system, and design the expander for low speeds for longevity, and just make it as simple as possible for easy maintenance. Go for steam temperatures on the order of 500-600F, and pressures on the order of 300 psi. Make full use of the heat in the steam exhausted from the engine by condensing all the steam in a large store of water in an insulated vessel, and the steam/water system should be closed (i.e. fully condensing so little or no water make up necessary). A low power unit can pull this off without difficulty. Finally, the furnace has to be designed for firewood (i.e. wood splits) as anything else requires too much processing. It needs to be a gasifying furnace design, or possibly a rocket furnace. If someone is already burning a lot of firewood for heat, then this seems a promising configuration.


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## simi-steading (Sep 27, 2012)

I'm looking for an even better alternative for electricity... Since I've got free gas, I'm keeping an eye out for an old Lister engine I can afford and strap a low RPM generator to it... Electric for the cost of crank oil and a little diesel since you'd have to run it in a dual fuel mode..


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## buenijo (Jun 14, 2012)

simi-steading said:


> I'm looking for an even better alternative for electricity... Since I've got free gas, I'm keeping an eye out for an old Lister engine I can afford and strap a low RPM generator to it... Electric for the cost of crank oil and a little diesel since you'd have to run it in a dual fuel mode..


Oh, heck yes. If you've got practically unlimited access to free natural gas, then you're set. 

Might find something at http://www.diesel-electric.us/


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## MichaelK! (Oct 22, 2010)

th_Wolverine said:


> 1. Steam engine: time tested to work to run engines, an example is shown in this youtube video


OK, the parts shown in that video are NOT a steam engine. It isn't even a toy steam engine. Just a bunch of random parts thrown together by a clueless teenager that doesn't work. If you want to be serious about alternative energy, I'd suggest you start doing some REAL research before you go any further.


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## AJ W (Jul 30, 2020)

Jim-mi said:


> Live steam is inherently very dangerous and requires full time attention.
> Yes you can dig up utube video's of very small "units" that will produce a tiny amount of power . . . . .But the larger the rigs---meaning more usable power--the danger factor really jumps up.
> Ask your self if you want to spend all your day tending a steam rig . .??
> 
> ...


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## Wolf mom (Mar 8, 2005)

Ever thought of wind power to assist your solar in keeping batteries charged?


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