File:Passive Greenhouses in Early Spring.png

English: Another winter (technically spring) solarpunk scene, this time centered around passive greenhouses. The idea is that since the sun will mostly be coming from one direction in colder climates, you surround the other sides with brick or concrete walls, which absorb heat during the day and radiate it at night (which is when you cover over the plastic). The first time I saw an article about this design I was amazed I’d never considered how poorly standard greenhouses fit our use case up here. I worked on a farm for years growing up and we heated about half of them at least through December. Single or double ply plastic sheets and corrugated white plastic siding nailed to stick frame walls on the ends. Garage doors only on either end. I can’t imagine how much they cost to heat. It’s that one-size-fits-all-just-burn-more-gas approach I think a solarpunk society should reconsider wherever it finds it.

In the photobash, I set these greenhouses into a south-facing hill, to further regulate their temperature. I also included a couple examples of passive heat – black painted water tanks and water barrels, to absorb sunlight and radiate warmth at night, along with bins of compost or manure, which put out both heat and CO2 as they decompose (making up for the lack of an oil furnace exhausting into the space to boost CO2). Some farms further boost the heat and CO2 by sheltering animals inside.

The top greenhouse would run cooler, and has cole crops (kohlrabi, cabbage, ad broccoli) and beans and potatoes in it. The lower house is hotter and has tomatoes, cucumbers, squash, and peppers.

The lights are almost entirely for artistic reasons – my favorite winter scenes have the warm yellow light of human spaces contrasted with the almost monochrome blues of the winter outside. I wanted to do a solarpunk scene with that, and the greenhouses were a good fit. (Worst case, we’ll say they’re trying to extend the daylight hours a little). The design in this one likely isn’t perfect – I’ve only ever seen photos of the real thing, and the ones shown online vary but most are much larger than these modest greenhouses. I also didn’t get to include seedbeds, which would probably be the main priority this time of year. Presumably, they have deer fences erected further out.