This cool project for a solar-powered 24 hour greenhouse comes from Instructables user and TreeHugger favorite, Joshua Zimmerman. Zimmerman has provided us with some great solar-powered projects before and you can check out even more at his site BrownDogGadgets.com.
If you have some experience with DIY gadgets, you should be able to easily tackle this 24 hour greenhouse, which uses a solar panel to generate energy for providing a little extra light for house plants during the night. Included is also a 10-minute super easy version that uses a 2-liter plastic bottle and an old LED garden light that even beginners could handle.
"I live in Wisconsin, which is usually rather nice. Unfortunately Winter has been going full blast for months and shows no signs of letting up. For a mammal like myself this kind of weather is annoying but not overly harmful. For my various house plants this weather is quite deadly. Especially to the very small plants I'm trying to cultivate on my kitchen table.
To help my plants get a leg up on this weather I decided to build a greenhouse. The only problem is that a greenhouse only works part of the day when the sun is up. To give my plants a really boost up I'd have to throw on some grow lights which gets expensive and are way overkill for my very small plants.
What I needed was a lighting system that turned on only at night. Not a tough task to accomplish so I decided to mix it up a bit and add an element of solar power to it. What I ended up with is an acrylic little plant incubator that runs night time lights powered by solar energy. (Just like the plants.)"