Jim,
This is in response to “Three Liabilities Addressed: Refrigeration, Sanitation, and Fuel” article [by James D.]: Refrigeration is only a big problem for survival when one makes poor choices and is dependent on obtaining fuel for a generator to power a typically inefficient refrigerator. Refrigeration is relatively easy if one has planned ahead and made the right investments in both refrigeration and power generation before a crisis when one can still get the required system components.
Most refrigerators and freezers are inefficient, often using 500 to 1,000+ watts per hour. Choosing the right refrigerator, adding insulation to its exterior, and being careful not to open it too much can get the load down to about 100 watts per hour. Australian Tom Chalko published an article in 2005 showing how to convert a standard chest freezer into an extremely energy efficient refrigerator that uses 0.1 KWH per day.
A 750 watt photovoltaic system (five 150 watt panels, a 750+ watt inverter, and a battery) is enough to power the 100 watt per hour refrigerator. However, Tom Chalko’s design only needs one 40 watt panel [$300 to $400 at typical retail ripoff rates], a 40+ watt inverter [$34 at The Inverter Store], and one battery – the total investment would be about $500. Inverters will typically last 10 years for the premium brands (e.g. Fronius, Kaco, Xantrex, SMA America) while the panels will last 25 to 40 years. Note that using a 12 volt DC refrigerator eliminates the need for inverters.
One could easily stockpile several extra small inverters and store them in a Faraday cage. They also would be a good post-collapse trade good.
For multi-generational collapses once the inverters and solar panels die, lead acid batteries and DC direct driven wind turbine technologies are sustainable and could be locally manufactured using home garage scale workshops. In an absolute worst case scenario, [in northern climates where ponds and lakes freeze in winter] one uses the refrigeration solution used for hundreds of years in Europe:
1) Find a cave or build a sufficiently large underground root cellar.
2) Heavily insulate the structure using natural materials such as straw bales
3) Every winter, use the natural freezing cycles to make large volumes of ice blocks
4) Store the ice blocks in the structure and insulate them with saw dust
5) Store food in the portion of the structure surrounded by ice
6) Use smaller, insulated ice chest in individual homes for day-to-day refrigeration and resupply the ice chest with ice from the large storage cellar or cave every several days.
Ultimately, knowledge of the right appropriate technology (some high tech but mostly alternative design approaches successfully used in the past or in third world countries that were often abandoned in the West as cheaper energy destroyed their economics) can show us ways solve many of our daily technical problem.They can tell us what tools, supplies, and components we need to stockpile while they are still available (including many items that may not be on common survival check lists). They can also allow us to live in a more sustainable, low energy fashion that saves money in good times and maintains a minimum living standard in post-crash or post-disaster scenarios–when the bulk of the population who failed to prepare are struggling simply to live. – Dr. Richard
JWR Replies: I agree with you on the efficacy of PV-powered refrigeration. A small system can indeed produce sufficient power for a small refrigerator–certainly enough for insulin storage for a diabetic. Ditto for anyone with sleep apnea that is dependent on an electrically-powered constant positive airway pressure (CPAP) breathing machine. One such PV power system was detailed in SurvivalBlog back in early 2006. And, as recently mentioned in SurvivalBlog, pre-packaged PV power systems are available from Ready Made Resources. (A loyal SurvivalBlog advertiser.) They even offer free consulting on system sizing, site selection, and design.