Solutions to refrigeration when electricity is scarce
by Michael Hackleman
I have gotten so caught up in the various ways of perfecting refrigeration that I have failed to realize that one of the best schemes is to reduce the need for it by pursuing alternatives. Anybody who uses a refrigerator seldom considers what mankind did before the refrigerator was developed. Some may remember cutting ice from lakes, storing it in well-insulated buildings, and the daily task of transferring small chunks to the icebox in the house. But let’s go back still further in time.
In the pre-icebox era, how was food preserved? Basically, people used one or more of four techniques: root-cellaring, canning, dehydration, or controlled supply. Let’s look at them one at a time.
Build and use a root cellar.
The secret to the root cellar is that it?s tucked down into the midst of the biggest thermal flywheel we know, the earth. In a 12-hour span, air temperatures may vary as much as 100 degrees F above ground. Several feet into the earth, however, there may not occur a one-degree change. Season to season, the same in-earth spot may vary by only 10-20 degrees F.
Traditionally, root cellars are built under the house. This provides easy access and cuts down on the cost of separate construction. Another important aspect of this design is that the house itself acts as a buffer against surface-side temperature fluctuations. One built separately from a house must be snuggled down a little further in the ground to avoid the influence of temperature variations at the cellar’s weakest boundary, it’s ceiling and entrance.
What kinds of food can be stored in a root cellar? Garden produce and grains. Vegetables have a natural protection against weather and, when ripe, may be kept for exceptionally long periods merely by keeping them cool. Most types of grains stored in air-tight, air-evacuated (vacuum or gas-filled) containers, and kept from temperature extremes and direct sunlight will keep almost indefinitely. It may appear that a root cellar?s main function is to protect food from the ravages of summer heat, but this isn’t true. Vegetables are just as susceptible to damage by severe cold or freezing. So, the root cellar’s moderating influence is also essential during winter months.
Grain and vegetables constitute less than 50% of the average person’s daily diet. Also, the root cellar may prove inadequate in light of the cooler temperatures required to preserve other foods?dairy and poultry products, meats, and frozen vegetables. Nevertheless, the root cellar keeps vegetables and grains out of the refrigerator and, in the process, cuts down the size of a unit needed to handle perishables.
Learn canning for foodstuffs.
Canning involves all types of foods but focuses principally on fruits and vegetables; preserves, pickles, jams and jellies are the end product. However, meat, poultry, and seafood can also be canned. Canning requires no energy in storing the finished product, but it will require a strong heat source and the energy of your own labor to prepare. By comparison, freezing foods predominates now for its obvious advantage in convenience, but its main disadvantage is high energy consumption for the duration of the storage.
Improper processing when canning produces a toxin which causes botulism poisoning. It’s the fear of this possibility which turns prospective canners away from this food preservation technique. This is both unreasonable and unfortunate. When tried-and-proven recipes are used and other processes are followed for jar preparation, there is no danger. Backwoods Home Magazine has had a number of articles on canning in past issues.
Dehydrate your food.
Another food preservation technique is dehydration. Involving low-temperature heat, freezing temperatures, or vacuum, this process drives water from foods. As a result, the final product is sealed against the normal pace of decomposition. The final product can be eaten ?as is,? or reconstituted with water.
The most widely-known example of food dehydration is beef jerky. Although the process is carried out in gas or electric ovens nowadays, the original version involved stretching the thin strips of meat out on sun-baked rocks. In addition to the preparation, the cook had to stick around to fend off animals, birds, flies, and other insects lured by the delicious scent.
A person serious about using this food preservation technique could easily build a solar dryer for unattended drying of bulk quantities of fruit, produce, and meat. The popularity and high cost of dried fruits and meats should be indication enough of what you could do with any surplus dried foods from this inexpensive process.
Control and pace your food supply.
A controlled supply means that you keep your food alive on the hoof or on the vine until you’re ready to use it. If it’s ripe, it’s ripe; if it is not eaten or preserved, the food will rot, spoil, or become unpalatable. Therefore, in a controlled supply, one staggers the ripening or aging of food so that it comes due as frequently and as reliably as a trip to the store each week.
Meat supplied from domestic animals is another issue. Unlike the relative freedom we may enjoy in picking small or large quantities of vegetables, fruits, or nuts, with animals we’re stuck with irreversible harvests. What portion of it we don’t immediately consume must be preserved or suffer a loss to spoilage. It wasn’t long before raising rabbits for food got to me, and the experience nudged me just that much closer to being a vegetarian. It was the extra effort. When we finally got to the point where there was sufficient food coming from the gardens to maintain our rabbits without the outside purchase of feed, it was also easy to see that we were adding an unnecessary step. In the final analysis, then, the extra energy, water, and grain was too great to justify the meager return.
A lot of ideas and techniques have been covered in the foregoing sections. While you catch your breath, may I suggest a plan for implementing some of these ideas?
- Seriously consider exactly what it is you want that requires refrigeration.
- Consider one primary and (optionally) one or more secondary power sources for refrigeration. No single source?or the equipment which converts it to useful form?is 100% reliable.
- What conversions, modifications, and replacements appeal to you? Which of these can you perform yourself? Do you have the time, energy, skills, and tools? What will the materials cost?
- If you need (or want) help, is it available? What will it cost? Is it worth it? Be honest with yourself.
- Are you willing to change some operator habits? Do you need to re-site the refrigerator?
Solid answers to these questions will make other options clearer and, hopefully, subsequent decisions easier to make.
(Michael Hackleman, P.O. Box 327, Willits, CA 95490, is the author of Better Use of Alternative Energy and At Home with Alternative Energy. Currently out of print, both are available at libraries.)
Another option is to buy a small electric freezer, and re-make the design, just enough so you can add about 8-12 inches of Styrofoam insulation. The back or sometimes bottom are the areas where the heat exchange occurs on many models (do not block heat exchange). That warm side or heat output area needs to be vented away or out of the place where the freezer is used. Then with all the newly added foam insulation and the use of the a solar electric source such as 300-400 watt solar panels or small turbine and about 8 large batteries designed for charging and used in solar power systems.
Then a person can produce ICE (for cooler(s)) and keep foods frozen.
I am speaking about one of those small top chest freezers in 13-15 cu ft range, and not a large style.
Also I am talking about a brand new unit that already uses far less power to run that units more than a few years old.
Also if you plan to use a 110 volt style you will need to buy a matched inverter, not a big one that draws a lot of power to be at the ready, but one large enough to do the job by a nice margin. 2000 watt or so. Would be a fair choice.
Chest type units (both refrigerator and freezers) loose far less cold air when opened than vertical door units. When a door is opened, the coldest air at the bottom spills out onto floor area. With chest types, opening the lip spills no cold air and requires less energy to ‘recover’.
Refrigerators seem to be way under insulated, so as to make them roomer is same space. IMO, this not a good idea at all. Far better to make more room for insulation (on exterior) and use far less power. Then renewable energy sources become economically attractive.
Couple other interesting tid-bits when considering refrigeration alternatives…
The temperature in most places in North America about 8-10′ deep is constant and will always be at whatever your annual average air temperature for that location happens to be. This will hold true as long as it’s dry ground and not into a water table.
Cold is simply the absence of heat, heat is the active player here, you are always dealing with keeping the heat ‘out’ rather than the cold ‘in’. Radiant heat protection, rather than convective or conductive, can be more readily employed and more easily provide bigger gains than the other two. Though protection from all should be used.
“Over 40 years ago, NASA developed Radiant Barrier technology to protect astronauts in the Apollo Program from temperatures that ranged from 250F above to 400F below zero Fahrenheit. This feat in temperature control technology enabled the astronauts to work inside the Apollo Command Module wearing short-sleeve shirts, with temperatures similar to those of a regular business office. The Radiant Barrier has been applied to virtually all spacecraft since then, including unmanned spacecraft with delicate instruments that need protection from temperature extremes. It is also applied to the astronauts’ space suits, protecting them during space walks.
Made of aluminized polymer film, the Radiant Barrier both bars and lets in heat to maintain a consistent temperature in an environment where ordinary insulation methods will not suffice. The aluminization of the material provides a reflective surface that keeps more than 95 percent of the radiated energy in space from reaching the spacecraft’s interior. In space suits, the thin and flexible material reflects the astronauts’ body heat back to them for warmth, while at the same time reflecting the sun’s radiation away from them to keep them cool. Using conventional insulation, a space suit would have required a 7-foot-thick protective layer.”
I’ve seen the tops of trailer houses in the summer that you could boil an egg atop, but, when coated with a thin reflective layer of radiant barrier, you can walk atop them in your bare feet. That heat then is not getting inside where the air conditioner has to then deal with it.
Look for any opportunities to wrap any refrigerators (though not where hot coils are beneath), ice or cold boxes with aluminum foil, shiny side out, and you’ll have a radiant barrier in-place reflecting heat away. It just needs an air space on the outside, and not be butted up flat touching against anything, otherwise the heat transfer will conduct through it.