It seems strange to think of the
suns warming rays enabling the storage of things at below freezing
temperatures but, that is exactly what solar powered freezers are
designed to do. There are numerous different shapes, sizes,
purposes and prices associated with these specifically assembled
devices. Products range from those used in RV's and in remote
locations to massive industrial scale, multi-million dollar setups
like the one at
United Natural Foods (YouTube Video). Although the initial
investment may seem steep, having the piece of mind knowing that
your frozen foods or medicine do not rely on the availability of
power from the utility company is priceless. Also, over time
the energy savings will compensate for the upfront costs.
Below is some information regarding traditional and sun based
Consumption of Traditional Units:
Typically 400-800 Watts (may require 3 to 7 times
the wattage at condenser startup)
Voltage: 110 AC
Average around 85 Watts or less for comparable
sized units (in most climates / temperatures)
12v or 24v DC or 110 AC
A popular manufacturer of solar freezers is
SunDanzer. I've included a specification
sheet & owners manual of one of their
popular products as a reference. The documents can give you
some idea of things to consider when buying a similar machine.
It isn't absolutely necessary to buy a freezer
specifically designed for use with a solar setup. You can use
a traditional unit with a power inverter (changes DC to AC) and
more, larger batteries. It would also require a larger and
more expensive array in order to provide the high power requirements
of a normal unit. The age of your existing freezer is also a
consideration as newer models are more energy efficient. (energy
A few things you can do to save money &
1. Turn up the thermostat (temperature)
dial. Most people keep the setting lower than is required for
adequate long term food storage.
2. If you have a manual defrost freezer,
clean it out regularly when ice builds up more than 1/4 of an inch.
3. Check and replace loose seals on the
4. Clean the coils. (behind or underneath)
5. Make sure there is adequate ventilation
& that the freezer isn't sitting in a warm place / direct sunlight.
6. If your freezer is older, consider
getting a newer model.