how to heat this greenhouse without electric

Linked several threads as well as the FAQs here on heating below.

Dave

Here is a link that might be useful: Heating a greenhouse discussions and FAQs

Thank you Dave !

smokymist:

I know this probably doesn't help you at all. But there is no cheap way to heat a greenhouse if you want warm temperatures at night. So my approach is to grow crops that are happy with warm days and cold nights. I heat only to low 30s and that only because I have citrus trees. Some of the cool season crops like greens and such would grow at even colder night temperatures.

My heating bill for the entire winter in a 1700 sq ft greenhouse is a few hundred dollars. It would be even less but we probably have the highest natural gas prices in all of Texas.