Growing year round in a passive solar greenhouse without heating

I am growing year round at Olds, Alberta, Canada. Our latitude is 52deg and elevation is 1000m. The passive solar greenhouse does a great job in extending the growing season in such a challenging place. No artifical heat source is used. The only heat source is sunlight. Passive solar greenhouses are very cost effective and environmentally friendly solutions to vegetable growing. Video taken on Dec 28th, 2020