GrandPod asked elsewhere about solar power for the 'pod.  Here is a summary of info previously posted, plus some new stuff:

Your best option for a fan or anything else that can run directly from 12 V DC, is to use the 12V instead of an inverter. You loose some energy in the conversion to AC, usually about 15% for small inverters. Plus the inverter needs some for itself, often around half an amp. Finally you use 10 times as much amperage from your 12 volt battery as your 120 V AC load needs.

So running a 1 amp AC load will use about 1.18 amps AC, or 11.8 amps DC. Add half an amp on the DC side for the inverter and you are up to 12.3 amps from the battery. Just some numbers to think about.

Its possible to buy a solar panel or two and a charge controller to keep your battery charged during a long trip, however, for the cost of a 50 watt panel as part of a random RV kit I found on the 'net (over $500), you would do better to just buy a 2nd battery and/or use the "every other day" technique.  

A 2nd battery will last along with your 1st battery for a good week or more during the summer.  The biggest electric user in a camper is, ironically, the propane furnace.  So two batteries may not last by themselves during a fall or spring trip.

Then there is the "every other day" method.  Lead acid batteries charge very quickly at first, especially if they are more than 20% discharged (and they shouldn't be discharged more than 50% on a regular basis).  So if you use a good set of jumper cables and jump the battery to your tow vehicle's battery for a half hour every other day (while your vehicle runs), it will retain a decent level of charge.  However, after a week or so it should be fully charged to prevent permanent damage - lead acid batteries are happiest when they are kept fully charged.

There is lots of battery theory and a little magic behind these recommendations, I can explain more if necessary.