As someone mentioned, Easy
Bake Coffin is the best idea. I've been toying with the idea of using solar panel + battery to power a crock pot (small 80 -120 watts ) I didn't know the Easy Bake Coffin idea was around till just now, but my idea was to enclose the crock pot within a wooden cube first (plywood with hole for the power cord and a top hole for steam and maybe a thermometer) . Then install a fishtank like( or other thermostatic) switch that will keep the crock pot within ?5 degrees of cooking range ?180-185 and prevent pot from overheating and damaging element. Next, using foam board/radiant barrier cut panels, continue to add onto the existing plywood box to about 4-5 layers. With 1/2 inch material that should give r value around 5-6. Goal is to get to the point where only a fraction of the OEM watts are actually needed (ie 20-25) to maintain cooking temperature. Then your batt only needs to run the power 25 percent duty cycle or 15 min of each hour and it's same as using the OEM 80 watts at full duty. Theoretically, if you have a single 100 watt panel on a cloudy day, it could cook a whole lot of beans and not drain out the battery. The physics/thermodynamics says it will work, since by adding insulation, you are approaching IDEAL conditions(heat loss minimization) for the formula for water heating and the cooling curve for a liquid(namely water). Next will be micro refrigeration, using small cube mini fridge. Crazy and zany but these ideas may be useful for off gridders( where every watt counts) and in an extended grid down situation
