CHP Engines, a question about RPM and recommendation request!

Call to ALL CHP enthusiasts. I am putting together a CHP (combined heat and power) unit based on a wood gasifier. Syngas will be created and piped into a Kohler Aegis 26hp LH690 which will turn a generator which will power a battery bank which will power our farm. I do not need so much power but this is the smallest commercially available gas powered water cooled engine that I could find. It produces 26hp at 3000RPM. Question. Is there some reason I could not set the governor to run the engine at 1200 RPM? Acording to the power charts for this engine that should give me about 7-8hp which, although still more than I need, would put me in the ball park of my energy goals. I am also thinking this should significantly reduce the engine wear and tear per hour and should therefore significantly increase the engine life. These engines should get about 10,000 hours as is, I am thinking (hoping) I could get 20,000 plus hours if I run it like this. What do you say? Am I crazy? On the right track?

Also, if you know of another low power liquid cooled engine which you think would work better in this set up, let me know!!

Viva la decentralized power!

Bump !

Allen thanks for the bump! I was hoping to get some input, especially on running the kohler at 1200RPM.

Could you.hook up a motorcycle engine?. Plenty.of cheap reliable 50-100cc 4 stroke carbed engines produce less than 26 HP.

Regards the rpm, where does the 3000rpm figure limitation come from in the first pllace? Partially block airflow thru the radiator if engine not getting up to temp at lower revs. I'm not familiar with your model of engine, can you get advice from the manufacturer?

-Methane being the principle gas in Natural Gas, I would think you could check with manufactories that build engines for Nat. Gas . I expect that you will find due to

a reduction of heat energy in Methane that the power plant will run a couple 100 rpm (or More ) lower depending on how it was tuned.


I also would be concerned with water and other contaminates in the gas, if not filtered out it is likely that instead of a cooler running, long lasting power plant the

contaminates could increase the amount of required maintenance ! Hope this is timely and useful, for the good of the craft ! Big AL

Some engines are not meant to pull load at part throttle--idle or full throttle only. The issue is the water and oil pumps, they are not designed to provide enough flow to be under load at low RPM. I do not know about that engine in particular.

You also start getting into weird airflow pulsing issues anytime you try to run a one or two cylinder engine at low rpm with wood gas generators.