The solar battery chargers are excellent. Put one on the tractor, on the backhoe, and on the Caterpillar. The batteries stay hot. No need to use the jumper cables ever. They were a gift and they are great.
I have a small inverter (converts 12 vdc to 120 A/C). You can run box fans, lights (and those flourescent bulbs don't consume much juice) and even an ice cream maker. I have thought of getting some deep cycle batteries and hooking them to a solar charger just for the inverter. That would be expensive and it would also just be a luxury item. For now I can power the inverter off of the truck batteries in emergencies. We use the inverter to power pallet scales as part of a sideline buisness (patio stone sales). Now that I have it, I use it for lots of other things too.
I have studied wind power generation for years but have never partaken. It is just a fascination. Prices have dropped and technology has improved through the years.