Would you believe it, it is possible to run a freezer off of a single solar panel? Actually, since there is no sun at night, you’ll want to run the actual freezer off of a deep cycle battery and use the solar panel to charge the battery. This means you’ll also need charge controller for charging the battery from the solar panel. But with a setup like this a solar powered freezer can keep you from lossing your frozen foods during an extended power outage. This also makes these units good for off-grid situations like a cabin or boat.
Most solar powered freezers achieve their efficienty by using extensive amounts of insulation in the walls of the unit and the most efficient compressors available. Most manufactors don’t add a lot of bells and whistles to their solar powered freezers but do build them to last.
One of the most common brands of solar powered freezers is Sundanzer (they actually convert Electrolux freezers with permission). Their line is not nearly as extensive as the major freezer brands, offering only a simple solar powered freezer in three different size. The sizes of freezers along with the solar panel required to run them that Sundanzer offers are:
- 1.8 cubic feet, 110w solar panel
- 5.8 cubic feet, 175w solar panel
- 8 cubic feet, 215w solar panel
As the storage capacity goes up, so does the energy needed to run it. You should make sure you will be able to fit everything you want into the smallest, although it may be enough for a remote hunting cabin or something that you just want to keep a jug of cream cold for coffee. The corresponding battery is also going to need to be inscreased in size as the larger units are considered.
If you are thinking about a solar powered freezer to supplement or replace a traditional freezer the larger sizes are going to be of more interest. There will be little more up front cost, but an interesting aspect of solar powered freezers is that after you have the required components it costs the same amount to run them – NOTHING! The jump in size from the 1.8 cubic foot to the 5.8 cubic foot is almost three times, but the cost increase is only about twice as much, so if you think you’ll need to the space the larger is the most cost effective per cubic foot.
One aspect of the Sundanzer solar powered freezers that many people may find annoying is that they only come in a chest type freezer. This is to reduce the amount of cold are lost when the freezer is opened. As a freezer the chest aspect may not be too bad, but the Sundanzer freezers can also be run as a refrigerator, which requires somewhat less power.
Here is a good video I found on YouTube going over the Sundanzer 8.1 cubic foot freezer.