One would think! I tried to convince one neighbor that insulating the north side of her little greenhouse would help, but she insisted it needed every bit of light it could get.
Trace Oswald wrote:It would take a lot of convincing argument before I believed that cloud cover could make the sunlight come in from the north side of a greenhouse, especially in the winter when the sun is much, much lower in the sky to the south.
That is definitely similar to what we can experience. My reasoning is that least with insulation, I could hold on to any heat that I decide I need to add. My understanding is that part of what makes the Chinese Greenhouse model different is that they roll insulation down over the plastic in the winter.
low and weak sunlight combined with cloud cover means no solar gain above what it loses. Obviously insulation would help with losses but it wouldn't help with 3 weeks with no sun.