Update: Added info about Zeolite-water ice makers and re-edited.
When your electricity fails, with it goes your ability to refrigerate. A well-insulated, full refrigerator will keep the perishable contents for perhaps 4 hours with the door kept shut. A full freezer should be fine for 48 hours. See Keeping Food Safe During An Emergency for further recommendations.
So, what can you do if power goes off for days or weeks? Well, you could use a propane refrigerator or if you would prefer to prepare ahead of time and like the notion of both independence and sustainability, you could try building a solar ice maker (pdf).
So you’re tired of hauling ice every morning, but still need to preserve a lot of food. There are methods to preserve food other than freezing or refrigerating, which include canning (the subject of a future post) and dehydrating, otherwise known as drying. Properly dried, food enzymes are deactivated to prevent discolouration, vitamins are preserved, and the moisture content is too low for bacteria or mould to form. Additionally, food becomes much lighter and sees a reduction in volume, making it easier to store. The question is how to dry food effectively?
Electric food dehydrators are available, but their obvious downfall is their reliance on electricity. They are still quite useful in preparing emergency rations for short-term problems like power outages or being house bound due to inclement weather. However, for those looking for a longer-term solution, or a sustainable one, I would suggest a solar food dehydrator.
This particular (pdf) dehydrator has been extensively researched and tested in laboratory studies. With some creativity and common sense I’m sure you can find ways to improve the design for your own use as well. For starters, how about foregoing the expensive stainless steel mesh and simply using off-the-shelf cooling racks instead?
If you’re going to make your own solar dehydrator, just make sure it doesn’t turn into a solar oven instead.