Peak Oil Food Cooling Requirements

From our earlier breakdown of energy requirements we can see we have some requirements for cooling our food for preservation (we will develop formal requirements shortly). While you should always consider alternative food preservation (smoking, canning, etc.), preserving food by cooling is extremely effective and convenient.

As shown before, a deep freezer requires roughly 600W power and uses 7.2 kWh/day; a refrigerator 600W and 4.8 kWh/day. What if we could reduce or eliminate these requirements altogether? The effect would propagate through our design, reducing our electrical needs, and therefore our power source (e.g. solar panel area, water wheel size, wind generator size, etc.). As electricity is one of the most expensive elements of a typical design, it is in our interest to run trade studies that have the potential to reduce our required electricity if it meets our other needs.

One of the most efficient food preservation methods (in terms of energy/labor per pound) is a root cellar. A root cellar is extremely useful for keeping food cool even in hot climates. Walton Feed has a good primer on making root cellars. A root cellar does not necessarily mean a traditional walk-in basement; it can be a vertical “chimney” in the ground with the food lowered by ropes or insulated with straw. If you live in cold climates, the winter provides its own freezer: some food can either be left in the garden or placed outside.

Effective root cellars can be constructed rapidly, such as the Pallet Root Cellar. There are also techniques using old refrigerators as deep freezers or root cellars. And of course, always keep in mind that some vegetables store better than others.

Preserving food using a means besides electrical cooling can cut a large portion out of your energy production requirements. In most cases, it’s hard to beat the convenience of having a refrigerator within easy reach, but using other methods of preservation can enable to reduce the size of refrigerator you need (or you can choose to eliminate one entirely). You should always bear in mind that a power failure could quickly ruin everything in your electrical appliances, as happened here. Be prepared to survive without electricity at any time.