August 25, 2019

Solar Pantry Part 3: Alternatives

Continued from "Solar Pantry Part 2: Analysis."

Trying to solve my potential problem of losing refrigerated and frozen food during a prolonged power outage sent me scouring books and websites for affordable ideas. People preserved their food for millennia before they had electricity and refrigerators, but like other traditional knowledge and skills, the how-to has been forgotten, lost, or simply discarded in favor of high-tech alternatives. Unfortunately, not all of the technology we laud has been terribly smart: the processing and overuse of fossil fuels for example. The simpler the better, I say.

So while Dan and I are discussing options and forming a plan, I've been collecting ideas. This is what I've got so far, pretty much organized from lower tech to higher. Obviously, not all of them are feasable for everyone, because they depend on regional resources and conditions.

Spring house - If one is lucky enough to have a wellspring on their property, this would be an excellent option. A spring house is a small structure built over the spring to take advantage of its cold water. The water flows through shallow troughs into which food containers (usually milk cans) are placed.

Graphic from Barns, Sheds and Outbuildings by Byron D. Halsted.
Water enters under the window and drains at the ends of the troughs.

I had friends who used an old chest freezer in a similar way. Spring water flowed through it via inlet and outlet pipes. The chilly spring water kept their milk quite cool.

Ice house - For those living with long hard freezes, this is an idea. Ice is harvested in large blocks from solidly frozen lakes.

Photo: Library of Congress (
There's an interesting ice harvesting photo story at A Continuous Lean.

Then it's packed in saw dust or straw in an ice house.

Indiana ice house. Photo from Library of Congress

Drawing of an ice house interior. Graphic from 
Barns, Sheds and Outbuildings by Byron D. Halsted.

The saw dust or straw acts as insulation and slows melting. Some farmers made their own forms to make their own ice blocks.

Cool chamber - A variation of the simple ice house.

Graphic from Barns, Sheds and Outbuildings by Byron D. Halsted.

The ice house is built into a hillside with a room underneath for storing milk, fruits, and vegetables.

Drips through pipe in ceiling and drains through pipe in floor.
From Barns, Sheds and Outbuildings by Byron D. Halsted.

Chamber Refrigerator - Similar to the cool chamber.

Graphic from Barns, Sheds and Outbuildings by Byron D. Halsted.

The chamber is built so that top, back, and both sides are surrounded by ice. The space under the ice is for ventilation.

Ice Box - No electricity required for those with a source for ice!

Israeli, I believe. Attribution: יעקב [CC BY-SA 4.0

The top compartment holds a large block of ice which cools the contents in the compartment below. Note the drip pan to catch melting water underneath. Ice tongs hang on the side.

Well shaft - For those who have an old-fashioned well!


A food box or bucket is lowered and tied off just above water level, where the contents stay cool.

Silos (trenches) - These aren't the grain silos we're familiar with. The French term means "underground excavation used to preserve foods."

Illustration from Preserving Food Without Freezing or Canning
by The Gardeners & Farmers of Terre Vivante

This example measures 16" x 32" and is 20" deep. A lining of brick keeps rodents out. Vegetables are packed in layers of dried leaves. The wood cover is heavy and air tight. A well-drained location is important.

Root cellar - A more familiar form of food storage. It is basically a handmade cave built into a hillside or of mounded earth. In modern lingo we could call it geothermal cooling.

Root cellar in Itasca County, Minnesota. Photo: LOC

Root cellars tend to get damp and musty, however, so good ventilation is very important.

Windcatcher - This isn't for food storage, but rather a middle eastern house cooling system.that seems to lend itself to food preservation, providing one has wind and a qanat (underground water transportation channel). The basement would the perfect place for a root cellar.

Click to enlarge. Attribution: Wind-Tower-and-Qanat-Cooling-1.jpg:
Williamborgderivative work: Monsih [Public domain]

It's an example of evaporative cooling. The principle is that water absorbs heat in order to evaporate, cooling dry air significantly and with much less energy than refrigeration. It's best suited to dry climates, because it apparently gets very musty in humid climates, where it's earned the name "swamp cooler" because of the odor it produces.

Zeer Pot - Another ancient middle eastern technology that takes advantage of evaporative cooling. Also known as a pot-in-pot "refrigerator." A small clay pot is placed into a larger clay pot and the space between is filled with sand. The sand is kept damp and evaporation keeps the contents of the smaller pot cooler than the ambient temperature.

My experimental zeer pot.

I tried this method when I was researching off-grid eggs, cheese, and meat storage for Prepper's Livestock Handbook. Unfortunately, my experiment was a fail because of our humidity. The higher the humidity the slower the evaporation. There's a techy explanation of all that over at the Rebuilding Civilization blog. If you have a dry climate this won't actually refrigerate, but it will act as a cooler to increase longevity of some foods.

Cold shaft (a.k.a. cool cupboard or California cupboard). Heat rises and this is what the cool cupboard takes advantage of. The shaft is open at top and bottom to allow a cooling air flow. Wire shelves inside the shaft hold food items.

Illustration from How To Live Without
Electricity and Like It
by Anita Evangelista

Screens at top and bottom keep rodents out. These work best if they are built on interior rather than exterior walls. You can see a modern one in use at the Lewisham House and Farm blog.

DC (Direct Current) Refrigerators and Freezers

SunDanzer fridge or freezer.

These 12- or 24-volt appliances can be powered by solar, wind, fuel cells (hydrogen), or batteries; sources that deliver DC (direct current) electricity, as opposed to the alternating current (AC) we receive from the grid. They're pricey, however, ranging from $700 for a dorm-size 1.8-cubic-foot fridge or freezer, to $1600 for a 13-cubic-foot freezer or a 15-cubic-foot fridge. Solar panels or wind turbine and batteries not included.

Thermal mass refrigerator - From Earthship Volume 3 by Michael Reynolds.

Attribution: KVDP [CC BY-SA 4.0

It's designed around a DC refrigerator (above) run on solar panels. For the diagram key see the summary at Wikimedia Commons.

Solar ice maker - About ten years ago four engineering students at San Jose State University made a solar ice maker for about $100.

Solar ice maker. Photo © San Jose State University

It was an example of absorption chilling, not a new technology, but their project seemed to create a renewed interest in the process. Absorptive chillers use heat (like the sun) instead of a compressor. A refrigerant (like ammonia) is heated, cooled, and circulated to produce temperatures cold enough to make ice. Combine a solar ice maker with an ice box, and that would be a wonderful non-electric way to have refrigeration. I'm still looking for DIY plans. [UPDATE: How-to at Knowledgeable Ideas, although it's too big for an ordinary small family.]

The absorption refrigeration cycle was discovered in the mid-1800s by Ferdinand Carre. He invented and marketed the IcyBall around 1858 as a cooling device in homes.

IcaBall refrigerator. Graphic from the Crosley IcyBall Manual.

The device was sold during the 1920s and 30s, but apparently was discontinued when a number of them exploded. I suspect this was because it required the owner apply heat to activate it. Getting distracted for even a few moments could chance disaster! There's an interesting webpage on it's history here.

Solar Refrigerator - Was invented in the mid-1930s by Otto H. Mohr. It also uses absorption cooling technology, and was said to only need two hours of sunlight per day.

Source: Modern Mechanix Aug. 1935 issue. Click to enlarge.

Mr. Mohr received a patent for his design in 1940, but it doesn't seem to have ever made it into production.

Wood burning refrigerator -  Another example of absorption chilling.

Click to enlarge. Image from Mother
Earth News. Click here for full article.

Developed by Dale Degler (in the 1970s I think), he calls it an intermittent absorption refrigerator. It only needs a 20-minute fire every 24 hours! I'm not sure he ever actually made one, however.

There are other ideas out there, like propane and LP refrigerators and freezers, but I stuck with ideas that use renewable energy sources. I don't mind buying the materials to make and set up the system, but the idea is to not rely on buying the energy or fuel to run them.

Obviously not all of these ideas are applicable to Dan and me, but they do show how it's possible to preserve food without electricity. And they have kept me from being too discouraged after my solar pantry feasibility study.

Next → Solar Pantry Part 4: The Plan


Cockeyed Jo said...

Good research.

Maggie said...

I've only just got around to reading your mini-series, so I am going to comment here for fear of them being missed on the earlier pages.

Someone was interested in the chest freezer to fridge idea and if they don't have access to the book you mentioned, there is a web page here

I doubt you came across an off-grid blogger in Scotland? I thought I would refer you to his use of a Lister diesel engine as a stand by generator both for power at the time and for keeping his battery bank charged. I know one use of Lister engines is in UK canal boats, but I don't know what an American equivalent would be. The blog has years worth of pages, but about a third of the way down the right-hand side there is a box with relevant links. Listers go on seemingly for ever if properly looked after. I think Dan might find that kind of thing interesting.

Florida Farm Girl said...

The root cellar reminded me that Mama "hilled" her sweet potatoes sometimes. A hole a foot or more deep was dug and then lined with pine straw. The potatoes were heaped in there and then covered with more pine straw. Then dirt was piled over the straw. As we used potatoes, we dug into the side to retrieve them. Put back as close as we could but also placed a small piece of tin roofing over the opening and weighted it with bricks or whatever. She swore as she aged that the potatoes had been changed so much that you couldn't keep them that way any more. She surely did it when I was younger.

Leigh said...

Thanks Jo. It was pretty interesting once I got digging.

Maggie, thank you for the links! It's always interesting to see what others are doing and I never fail to pick up some tidbits. The chest freezer conversion is something Dan and I plan to do, so I was interested in A Self-Sufficient Life's (and it seems to me I used to follow them a long time ago before they updated their blog and became "Dirty Boots"). Here's another good link for anyone interested - New Life on a Homestead. I'll post these links again when I get to the details on our own project.

I had never seen the "Life at the end of the road" blog and it looks interesting as well. I'm assuming he uses the alternator on his Lister to recharge his batteries. That's something Dan is currently researching, so I'm sure he'll be interested. Thanks again.

FFG, now that's a useful memory. Interesting that she observed that the seed stock had changed. It definitely seems that the "improved" varieties really aren't real improvements.

Ed said...

When I was a kid, every farm I can think of had a root cellar that was used for storing food. I "fondly" remember being sent out to retrieve a jar of something amount the spiders and snakes that also liked to call the root cellar home.

I'm sure a few probably still exist but all the ones in my youth were gradually pushed in and buried in favor of modern canning and refrigeration techniques.

deb harvey said...

herrick kimble writes about 'clamps' to preserve veg in winter right out in the field 'thedeliberateagrarian'

read of cooling towers in middle east where wind whooshes down towers attached to house and air becomes cool series of openings into tower to close off wind in winter but is cool in summer dry climate and reliable wind

Leigh said...

Ed, old root cellars certainly do lend themselves to creepy, LOL. I have several books on root cellaring, plus Dick Raymond's gardening book showing his basement root cellar. All are nicely done, well lit, and ventilated, which I suppose makes them pretty modern! I would certainly a cooler place than my pantry to store my canned good and things that don't really need refrigeration. 80 degrees is just too hot for food storage, though.

Deb, I have his book. I should take a look at it again, and maybe his oldest website too.

The drier climates truly have good options for cooling without electricity! In some ways I envy that, but on the other hand, I don't think I'd care overall for a more arid climate than we've got.

Cozy Thyme Cottage said...

You have researched lots of options. None feasible for us but hoping you can find the best one for you. Nancy

Rain said...

I like the ice house and ice box idea, but yeah, you really have to find a good source of solid ice. Reminds me of the old movies when people had their ice delivered. I knew a woman who lived off grid and she kept her food that needed refrigeration in a hole in the ground. Well, it wasn't just "toss it in the hole" type of thing was under a tree that always provided shade and she had a box down there. She said it kept everything pretty fresh but she wouldn't keep anything in there long term. In the winter, we often put things out on the veranda to keep them cold or frozen if the fridge/freezer is full.

Leigh said...

Nancy, I found all the ideas interesting, but few are feasible for us either. Still, it was a good research exercise.

Rain, people get pretty creative without a refrigerator! I sometimes wish we could keep things frozen on the back porch or even the carport, but our temps usually top freezing during winter, even when they go below at night. Every region has it's perks!

Chris said...

So many possibilities. I was going to mention the spring house, but figured you may have come across that idea already. I like low tech solutions as well. Anything which can help reduce your overall running costs, is a big plus!

Leigh said...

Chris, it would be wonderful to have a spring on the property. There used to be a well here, but all traces of it are now gone. Low tech is so much easier to maintain! And cheaper to repair, if it ever needs it. :)

Sandi said...

So glad I live now, but there is something so freeing about the simpler ways.

Leigh said...

Sandi, and they're still all very doable for someone who is willing to make a few lifestyle changes. Although I'm sure we all enjoy modern convenience. :)

Tea said...

You can find used RV refrigerators cheap, most are 3 way fridges and will run off 12 volt, 110, or propane. This would give you more options on how to power. Many of the smaller Dometic units can be switched from all fridge to all freezer.

Leigh said...

Tea, thank you for that. I've been keeping my eye out for used RV refrigerators, but so far nothing has come up. Being able to switch from fridge to freezer would be really helpful.