Yesterday it was nice and sunny. 8:00 Pm it was 32 degrees midnight 28 degrees down to 24 degrees.
The greenhouse did not go below 53 degrees the fish water was 66 degrees. No fossil fuels used. I have disable all venting until it warms up some.
Right now it is 12:52 pm and cloudy 30 degrees outside but the greenhouse is 67 degrees.
I always wanted a greenhouse but I did not want to dump hundreds of dollars in heating it to get the plants. That why this options is so fun that is not required.