New here

I am new to the group and am interested in building a gasifier generator to be tied to the grid. My local power Co. has started a new program to purchase power from renewable energy sources and included biomass with the solar and wind options. want to use an induction motor as a generator. need an engine that can produce 75 HP at 1800RPM and a gasifier sized for that any suggestions

Welcome to the site Larry! I moved you to the small engines area, you’ll get some good advice shortly.

thanks Chris I am looking forward to getting going on my project

That’s exactly what I orignally planning to do:

Before you get too deep into this, I strongly suggest that you meet with the utility people right now, to describe what you intend to do. I have heard of a few utilities that will allow induction generators, but most will NOT. One of the problems is that, if you do run one, you will find that you need to correct a big reactance issue that causes poor peformance. You do this by adding capacitance, which, in turn, can promote self exciting, a real no-no to the power company. Even without such correction, all utilities will still require all the protective gear that any other grid tie system would require:
-over voltage
-under voltage
-over current
-under current
–over/under frequency (yes, even with an induction generator)
-various kinds of anti-islanding curcuitry
Again, in my humble experience, you will find that most utilities are supporting systems that produce under 20KW or well over half a megawatt, where the equipment is already redily available. For “our” needs, it may be well into the $50,000 and up range. Not a problem if the whole system runs into the hundereds of thousands of dollars.
If you haven’t read this, please do:

My utility demands that anything connected to it must be UL approved. This, alone puts the induction generator out of the running…

I sure hope other jump in and prove me wrong,
Pete Stanaitis

This might need its own thread, I suggest a name like “Power Generation System Types”.

If one is NOT planning to tie the generator in to the local grid (or even if one is), what are the benefits/problems of using an old Induction Motor as a GenHead vs other forms of generating electricity from a woodgas powered engine, such as the alternator and “true” GenHead? What forms of power does one get out of each system?

Thanks Pete and Brian
I have met with the power Co. engineers and yes there are definitely several hurdles to overcome. I do have 2 30KW Onan generators and have thought about starting with one of those using the All Power Labs new grid tie equipment. I need to find a way to do it because of the rate they will pay per KW which is .44 USD per KW for a 20 year contract.
I don’t think they expected anyone to use biomass. only solar and wind and they wouldn’t be purchasing much as the sun doesn’t shine much at night even here in the tropics and the wind isn’t steady. A friend of mine bought a huge used 250KW wind turbine and they told him max 50KW per hour so he cant push in 250KW when the wind blows. I know it will be a long road but the potential is about $15,000 a month so it’s worth trying to figure out a way.

Morning AdminChris
I agree. Could you please put this topic back in the General Disscussion or on it’s own Forum section.
A 75 horsepower continuos woodgassed fueled engine will be capable of generating ~50 kW/el.
The 50 kW electrical output 5.0L GM V-8 has these specs. Fuel consumption listed there converted to woodfuel would be 125 POUNDS AN HOUR (57 Kg) using a 25 pound of wood fuel per gallon of liquid fuel. Even be 50 KG (113 pounds) each and every hour uasing the one KG woodfuel for each generated kW/h conversion.
And once this on propane rated system was ~30% power output derated for woodgas fuel to get this 50 kW/el desire the Operator would have to jump up to the listed Ford V-10 system with an even higher hourly fuel consumption rate.

SMALL Engine User would by the farthest stretch be thier 21 kW/el four cyclinder GM system then downrated on woodgas fuel to ~14.7 actual usable killowatts electrical. And that would take 35.5-50 pounds to as high as 48-63 POUNDS AN HOUR to wood fuel depending on the actual gasifer/heat recycling efficiency.

OPs design goals are 4X to 15X of the Small System Users here.
Put another way system Users here are trying to Replace, or NET meter offset $100 to at worst case $1000. a month in bought out electricity with maybe a bonus of some heat generation. Not be a $15,000 a month income Power producer.

No offense intended at all saying this. This type of effort or discussion belongs in a different category. Then by all means continue on.
This engine/gen systems link with powers and base fuel consumption’s to work off of is my contribution.

Thank You
Steve Unruh


Thanks for the comment Steve
I agree with the consumption figures, I was using 2.5 lbs/hr/kw or 125lbs or maybe a little less if the wood was dry.
Maybe you could help clarify something. I understand the energy value of woodgas is about 30% less than natural or propane but if I can run the engine at 1800RPM on wood gas wouldn’t it generate the same KW? in other words does the generator care about anything except the RPM? Or is what you are saying is that I cant make the 5.0 GM run at 1800 on woodgas?
Actually I have a high compression 5.7 GM from a marine application I want to use.
This does
have me a bit confused.
thanks Larry

RPM is not an indicator of power produced. The engine will make as many RPMs as the fuel and load will allow - that’s why an engine in neutral will rev easily at light throttle, while on the highway it takes much longer and more throttle (under load). An underpowered car may not be able to rev up at all if the load is heavy (steep hill); often times it loses speed and RPMs and you have to downshift. Downhifting doesn’t make more power, it converts speed into torque, thereby reducing the load on the engine, but also reducing speed.

In terms of a generator; you have a governor that is able to open throttle to the required level to maintain a steady RPM. If there’s no load, this will be very little throttle and hence less power output. Increasing the load will tell the governor to open the throttle more - but what happens when it’s wide open, and load is still being added? Eventually you will lose RPMs because the engine is out of throttle, maxxed out.

Thanks Chris that make it more clear.
I was looking at a marine 5.7 with roller cam and 4 bolt mains, but the power curve only shows about 90HP at 1800 while the GM 7.4 shows about 115HP I guess there is no substitute for cu inches. The 8.0 dodge would be great also.
I wonder what I would get out of the Onan 30KW genset I have with the 5.0 straight 6 Ford industrial. I hope it wouldn’t need full throttle on woodgas for 1800RPM.
The GEK which has I believe a max throat size of 4" runs the 3.0Vortex at 1800 on their 20KW power pallet.So would you think a larger WK would be able to run my 30KW?
Is anyone from All Power Coming to Indiana? I need a break from this Island and I might just have to head north

Hi LarryB.
Good. Good. You have a realistic assessment of the woodfuel needed. Failure Alligator #1 down.
Now I can see you are realistically assesing engine possibilities at a heavily loaded 1800 RPM. Add in the fuel injected Ford 460 V-8 along with The Ford Industrial version V-10.

Sorry I am not having a good brain week and having disconnect from the thoughts to the typed words. Brain Meds are lossing their effectivness. So gonna be short.
You want to shoot for 13/1 compression ratio in a moderate overbore to stoke ratio engine, with a relitivly short connecting rod to stoke length ratio. Want to keep your actual piston speed at the lower end of the range in actual feet per second/meters per second. Upper engine side you really want the equivalent to a high RPM open breathing intake/valves/heads. But contrary: a cam timed like a heavy pulling Truck, RV, and some Marine and factory turbo cars but with FAST lobe lift ramps. This is all from Jenbacker/Pratash/ Washashaw/IHC production engine expereinces for woodga; IISc lab and fields expereinces; Swedish government sponsored field experiences- and my own woodgas engines running. And experiences those such as MR Wayne, Vesa Mikkonen, APL tried to run higher compression diesels on woodgas.
For much of this be easiest to spend the 121 Euros and buy Mr Vesa’s book. He does build and design for both “larger” vehicles and stationary.
Member here Bruce Frence HAS done Chevy V-8 woogasing work also - his latest as a generator system. Member search his name here and read back on his Recent Posts for this.

#2 failure Aligator will be Idealism.
#3 failure Aligator will be an insistance to do everythig yourself out of pride and/or the belief you can do it all cheaper.

I have followed at least eight different attempts to “easy” Chevy small block V-8 gen-set build up a woodgas fueled system. Advised on two of these. These All failed to launch to completion except for Sean Frence’s and Andy Schofield’s (sp). Maybe someone can chime in with thier YouTube channel links.
ALL other efforts got 'et up by one or more of these first three Alligators. Hell-of-a-lot designing, parts sourcing, and fabrication insisting on all DYI AND Idealizing all of the steps from a bare engine A to a working system Z. Bellhousing? Engine to gen head driving 75 horsepower?

You Can easily bypass two of these crippling Aligators just by seaching out and buying an old Onan Industrial gen-set. These are US mainland available for 10 cent on the dollar versus new. The inline engines were 6 cylinder 240 and 300 cubic inch FORDs in 20 and 30 kW. For larger kW capacity it was the Ford 460 V-8 and the later EFI based V-10. You sound like an engine man. On the ealier types rebuild up to the CR with later high flow capabilty FI available cylinder heads and manifolding, intake and exhaust.
Locked now into a sychronous “Certifiable” generator sidesteps any $$$$ Idealism tendency on the genration side of it that WILL gobble you up.
Now with a “Certifiable” generator assembly you have a chance to get by Aligators #4 and #5.
These are your existing Power Supplier thrown up hurdles and you will “later” be told manditory “Public Safety” Insurance requirements hurdles.
That Aligator #4 will come at you as a seeminly endless dollar draining meat tearing pack of savages with engineering hardware requirements, different levels of reports that have to made (from professional source writers) and be “timely” filed. You will never be quite sure what is droving this one step after another. Real info needs? Real satey needs? Your current Island’s FUEL supplier jealousy? Lineman/power plant Union workers protecting thier rice bowl?

If I seem discouraging it is becouse of the all Alts-Energy grid-tie experiences here in Washington State. Doesn’t matter the Fed mandated law for power buy back. The current Power suppliers here Public and Private do not want our power input. ONLY thier own sponsored showboated with Fed and State public dollars projects ever seem to get past all of the crippling #4 and #5 Aligators to the actual appoved hook up stage.

I have a local picture I posted up in my photo album here of a local large tree forest owner drained out of over $500,000. USD trying to do this on a 30 kW tower mounted wind turbine. Followed this for 5 years in the local news papaer of him having dollar draining hurdles thrown up by Aligators in groups #4 And #5 one after the other.
He harvested more and more of his trees to buy his way past these, step by step.
Finally then a Fed Court Injunction put up by the Birders Groups forced him into locked rotor.
Bitter, bitter man now. Why the my picture is from so far away. He will shoot anyone now coming onto his propery with a camera anymore.

Heads up man. Listen to PeterS. This can become a soul wrenching black-hole experience.
Much more fun to Off-Grid develope and build a fist in the air, “Screw 'Em ALL!!” system.

Steve Unruh

HA! As I said I am having eyes through the brain to the hands dissconnect.
Reading back now LarryB you already have two 30 kW Onans with the Ford I-6 300 CID /5.0L in them.
And I did not answer your IC engine on woodgas power derating reasons.
O. K. My own opinions you understand.
Take the BTU fuels comparisions and throw them out the windows for piston IC engine running.
You can find the stociometric (ideal) energy of MIXED oxegen to HC fuels comparisions on the NET. Closer now - but throw these out the window too.

A piston IC engine has to be able to suck in enough atmospheric AIR for the 21% oxegen (along with the 89% nitrogen) to be able to oxidize each and every fuel H and C to make these formulas work. Gasoline fuel droplets sucked in only displaces ~1% of the potential air flow the engine is able to suck in. Vaporized gasious propane I recall (poorly) displaces ~3% of the potential air flow. Gasious purified methane (not diluted bio-gas) displaces ~5-7% of potential air flow.
Woodgas will displace ~50% of air flow the engine will be able to suck in through the same intake, valves and combustion chamber porting.
So #1; the engine engine starves for the oxegen then on woodgas to be able to make matching power.
Solution on one of those early pushrod valve I-6 5.0L would be a 90’s Ford pick-up/van fuel injection cylinder head, rams horn intake and exhaust manifolds. Get more combined gasses in and out.
Also been proposed is to turbocharge this engine. $$$ can-o-worms. Read the thread here with the imput by Vesa Makinen driving a woodgassed Audi SOHC V-8 with lots of experience doing this. Again buy the “other” Vesa M’s - Vesa Mikkonen book showing experiences doing this and what can go wrong with broken connecting rods from woodgas pressure boosting. Turboed engines at high loads, low RPM ussually just overheat melt pistons. Why the good factory system ALL from undernearth the piston crown, engine oil spray the pistons to cool them. See one of the turbo $$$ traps? Oversized oilpump then for the extra turbo spool bearing floating/turbo cooling and piston crown cooling oils. Then added oil cooler and lines to cool the oil transported heats away. Synthetic, expensive oils now to make everything live from oil heat breakdown. Only on the Internet are turbo’s ever a bolt on solution.

#2 power derating on wood gas is that all of these other fuels are actually pressure delivered to the engine. Sure. Sure. On gasoline carburation we generally mildly suction from a float bowl. Vertually no energy need there. It is the air flow restrictive venturi throat now having to pass woodgas too squeezing out half of the previous posible air flow that is the real power killer on these.
Wood gasifier has to be energy intensely sucked out through a char bed, ash bed, ash separator, cooling and filtering system to get into the engine cyclinders. ONLY FUEL AND AIR THAT GETS INTO THE CYLINDER COUNTS FOR POTENTIAL POWER!!
A running engine under power like your 350 producing 75 hp - bet you it is taking 5-10 real engine horsepower just to suck the gasifier fuel flow into the engine. Thats what the wattage of pressure blower systems to flow this same say. Mr Waynes “old engines starved for fuel gas” belief that he has now proven valid.

3rd: Then each and every air and HC fuel combination will have its own compression limits and under COMPRESSION burning speed rates. Good cartridge reloaders learn this one well at their own blow-out, blow-up peril! Flowing brass is too much pressure! Back off the poweder charge weights, bullet weight or change powder types. Take all of in the open air fuel burning rate comparisions for motor fuels and throw them out the window also! ONLY under in cylinder pressure burn rates count.

How well does the particular IC piston engine mechanical design combinations convert this building in cyclinder pressure spike curve into rotary shaft power?
Complex HC chains like diesel fuels need as much in cylinder time to be completely have ripped apart as many of the complex molecule by molocule H and C chains and then be oxegen combined to make power.
Wood gas combustible gasses are the simplest to completly combust. Then comes more complex methane. Then propane. With gasoline fractions somewhere between these and diesel fuels in in cyclinder time needed.
But woodgas has the “too fast burning rate” H2 and the “too slow burning rate” CO. Now mix these together blended with much combustion speed modifying atmospheric nitrogen and a bit of woodgas CH4 (methane) and you get somthing proven to be widely IC piston engine useable over a wide range of compression ratios, valving and internal IC piston engine dimension ratios.
Still real world proven loaded best at 13/1 CR with the internal engine mechanical ratios I already described.
Your fuel injected 5.0L Ford I-6’s and V-8’s, Dodge 5.2 L Magnum V-8’s fit in that window. The FI last converted Ford and GM big block V-8’s also.
The medium displacement V-8s some OK, with the Chevy 350 with the fuel injection cylinder heads, valving and porting also outstanding. Many other medium V-8’s if you really study these like the 400’s were all intentionally designed biasing sacrificing bore life for traded off greatest in-block series CID. Or opposite this like the 351W Ford, 307 Chevy, and 345 IHC with intentional valve/cylinder head flows choked down for school bus and commercial long life applications.

I hope this helps.
Steve Unruh

Most of the Onan generator sets in the 20KW range and up are 3 phase machines. I don’t have 3 phase power where I live, so I can only supply the grid with ingle phase power. I too, have a 30KW Onan, a 30EK. Yes, it can be rewired for single phase, but at only 2/3 the output. So please take this into account. May not be a big issue since you will lose about 30% on woddgas anyway.

Someone asked abut using induction motors as generators if you arent’ going grid tie---- Yes, you can do it. I made one a couple of years ago. Look for youtube videos on the subject “induction generator”. There is a book out there that tells all about it. Motors as Generators for Micro-Hydro Power [Nigel Smith] on . The neat thing about these systems is that you use old but serviceable 3 phase induction motors with a bunch of capacitors. That’s pretty much it. Of course single phase induction motors will work, too.
Keywords for searching:
C2C induction generator
SEIG (Self Exciting Induction Generator)

Pete Stanaitis

One limitation of induction generators is that they don’t work well with inductive loads. Because of this you can only start a motor >10% of the size of the generator. This is why they are not used on every day generators.

Finding a single phase motor in the size you are looking for may not be easy as most motors above a couple HP are 3 phase.