I want to build a generator.

It has been getting in the low 30's at night. I built a green house. I have an extra blue flame.

I have a gas meter and buy gas from the gas company.
I also have a gas well that was unhooked. It has pressure.

At my father in laws his gas well had to many houses hooked up to it. We installed a large tank and compressor (made with electric motor and ac compressor out of a ford.)

I am going to do the same here. I want to heat the green house with it free of charge.

All of this I can do.
After that I want generate power with it. They make continuous (prime) rated lp generators, mainly new low rpm units.
A car with 200,000 miles on it is the same as a motor run non stop for nine months. There lies the problem.

I would like to build a system with some where around 20-25 horse motor. I can buy a spare motor and swap and rebuild.

Or do I buy a 4 cylinder motor out of a junk yard and use to turn the generator and buy another when it blows?

How would you guys approach this.
I would like to power the whole house.

Your fuel source is nearly free, but the infrastructure to divert it into power is definitely not. Welcome to the utility's perspective!

In your shoes, I would buy a junkyard motor and work with that first to get yourself familiar with the prices and your needs. You'll want to tinker with it of course, so a common motor like a smallblock Chevy or Isuzu 4 cylinder would be my choices.

I've seen startup companies doing the next step up from what you propose; they have built a natural gas powered heat pump and electrical cogeneration system; the engine runs on natural gas, both the generator and the heat pump composite are driven by the motor, and the heat pump takes the heat generated by the motor and makes it available for use, generally as hot water.

This way, the system can both heat your greenhouse and provide electricity. THAT'S what I'd be building if I were in your shoes, brother!

Google natural gas powered heat pumps. No matter how cold it gets where you live, this will save you energy.

The next step up involves the same natural gas, but this time you send it through a hydrogen reformer and a fuel cell; the reformer catalyzes the gas into hydrogen, water vapor and CO². Use the last two in your greenhouse and send the hydrogen into the fuel cell, where it produces electricity at a far bigger efficiency rate than an engine powered generator ever dreamed of... and you still get heat to use the same way as above. This tech isn't quite ready for prime time, but again if I were you I'd be researching the living shit out of it. Free natural gas is a real boon, don't waste the opportunity!

What ever engine you choise , get one thats eazy to rebuid with cheap parts avaible

Most sources of natural gas directly from the ground are considered dirty with above average hydrogen sulphide levels

The nice thing about old trucks are you can buy aftermarket drives and put the generator in the bed keeping the truck moveable , The manifolds are simple to adapt as well

LIBERTYCHICKEN said:

What ever engine you choise , get one thats eazy to rebuid with cheap parts avaible

Most sources of natural gas directly from the ground are considered dirty with above average hydrogen sulphide levels

The nice thing about old trucks are you can buy aftermarket drives and put the generator in the bed keeping the truck moveable , The manifolds are simple to adapt as well

Click to expand...

Did not know this about truck mounted generator kits. That's all kinds of useful; mobile power generation, anywhere you can get the truck. Talk about rolling disaster relief!

If you do find yourself looking for an engine, I suggest you look into a Toyota 22r. They are well proven, simple motors. Once it wears out, rebuild parts are cheap and easy to replace. It's a fun weekend 'shade mechanic' project.

They made about 249 billion of these motor over the years, so finding one cheap is rarely a problem.