I bet the refrigerator is the biggest consumer of electricity on average. I'm guilty of opening the refrigerator a great deal over the day, often sitting there trying to figure out what to eat. Seeing as cruising sailboats are generally the most energy-strapped dwellings out there, they've created unique ways of prolonging ice (cold storage) on voyages.
The biggest change is switching to a heavily insulated, chest-style refrigerator. Obviously cold air sinks, so logically it helps to trap it rather then let it spill out over the floor.
The second is to use two chests, one large primary and another smaller secondary. In the morning, all the food stuff to be used during the day is taken out at once and placed in the second chest. By isolating the day's food, the main compartment can stay closed.
Anyone wanting to really save some money, the most efficient, (somewhat) conventional refrigerator I have seen is the Sundanzer brand. Supposedly, they can be powered by a single 150W solar panel. To be really efficient, some even cool the condensor coil with ducted outside air (depending on temperature). Why cool a fridge in a heated room?
Sundanzer Chest Refrigerator
- LostCause