A new trend in RV fridges?
while picking up some odds and ends for our upcoming trip, we poked around in some new trailers for some giggles fire places and tiny walled off bedrooms? obviously rv designers don't go camping! ...
Forum Discussion
stevemorris wrote:
quick question then, how much solar power is needed to run a modern high efficiency fridge? someone said 300 watts is required, about howmany sqft of solar panel is required and at what cost?
there are lots of variables of course and when running off the truck alternator as well, what are the ramifications of that. another 300 watts out of an alternator is significant
interesting thought, big enough solar array and the alternator wont be doing anything!
The res fridge pulls the 300w or whatever when it is cycled on which will be half the day or so, depending. When pulling 300w from the inverter, the inverter is pulling 30 amps DC from the battery bank.
30AH an hour. Hard for solar to keep up with that! It has to play catch-up when the fridge is in an off part of cycling. Dont keep opening the door!
Solar panels are in watts and expected amps is related to their watts and how much sun they are getting which varies all day as the sun goes up and down and around. High noon with panel aimed at sun is max amps. Flat on roof instead of aimed is less for the max.
Roughly, 130w will get you 8 amps at high noon aimed or 7 amps flat. Less before and after high noon. It is all proportional, so to get 30 amps at high noon flat on roof, you want about 4.5 x 130w = 585w and you need more to average out the day when amps are lower than at high noon.
Now it all depends on your latitude and time of year. Down South in summer is better for solar than up North in the winter.
Say you decide to go for it with two 300w panels at $200 US each. Plus the controller for another $200 and some wire $100, and you do it yourself (saving $1,000 labour) so you are at $700. But you need batteries to keep going at night and any daytime the sun is not shining. You need to calculate that for the fridge plus the other things you do anyway. A big battery bank costs another $700 maybe, so you are up to what that nice res fridge costs just to run that fridge. (of course you are running everything else too, so you cant blame it all on the fridge)
You absolutely cannot go off-grid for very long with a res fridge and spotty solar, such as on the Wet Coast in the Fall or Spring. That is what propane is for! Or a generator, which has its own issues for how long and when and where you can run it, and whether that will be enough.
