Refrigerators & Freezers
Efficient Refrigerators & Freezers
Efficient refrigerators for living off the grid using solar panels for your home should be the most efficient, lowest energy consumption available. Super-efficient electric refrigerators and freezers designed with 3 to 5 inches of insulation use only one third the energy of most standard units. This catalog shows the best of those solar designed refrigerators. They are the very best choice for smaller power systems.
Standard freezers and refrigerators can use 3000 watt hours each day. A few better models like Maytag MTB1956 18 cu ft can be found that use under 1500 watt hours a day, and cost around $900. You need to add about 500 watts of solar modules in the best year round sunny weather to operate; more panels needed in less sunny areas. Total cost $900 refrigerator + $3,000 solar = $3,900 to use the best conventional units.
Refrigerators that are specially designed for off-grid homes require fewer solar modules and less generator run time. All our refrigerators are rated in watt-hours power used per day. Watt-hours compare equally whether 12, 24, or 120 volt units. Divide watt-hours/day by your battery voltage, 12 or 24, to get amp-hours per day consumed.
Gas vs. Electric
A refrigerator's need for power matches solar electric production — more power in summer and less in winter. Adding solar modules for electric refrigeration raises the up-front cost, whereas propane gas is paid over 15 + years. Long term comparison is close either way (if gas prices don't rise). WARNING: COMBINATION GAS-ELECTRIC refrigerators are usable only as gas powered, not as electric. An electric heater running nearly full time replaces the gas flame. They use much more power than any electric compressor, so they are not practical electric units.
Sunfrost products have 4 to 6 inch insulation, and the compressor is on top where it can't put heat back into the box. The RF-16 model uses a total of 750 watt hours a day, about 300-400 watts of solar modules, depending on the climate.
Novakool products are smaller DC powered refrigerators made for RV & marine markets. With the same Danfoss compressor as the Sunfrost, these are smaller refrigerators but use about the same power. Adding 2 extra inches foam insulation to all surfaces except the door cuts that power use in half.
Sundanzer DC powered chest freezers are as well insulated and energy efficient as any available, using 200 to 800 watt hours/day, at better prices.