One way is to drive by night and park by day at picnic areas in public parks. Many are owned by cities, counties, states and the federal government. Most are stunningly beautiful.
Nobody questions a parked RV during the day, it's only at night time they come under close scrutiny when boondocking. Many picnic areas are free and you can typically stay there from the time the park opens until it closes. These types of parks generally don't have camping, but parking at the picnic area all day into the evening is no problem.
Many day use parks close very late in the summer like 9-10-11pm. One can stay until closing, then hit the road late at night. If you stick to the 24 hour places, you can generally do your provisioning at night too, such as buy gas and food.
If you need to stay in one area for a few days to rest up, then try to locate a day use park and a night time boondocking close together. For instance spend the night at Walmart (if allowed) then at daybreak move to the park until it closes, then back to Walmart or somewhere else in the area such as a Flying J.
You can download the Flying J guide that tells you which ones have RV parking.
Also consider joining the WalMart RV-ing yahoo group:
This group is the positive voice of WalMart Rving. We are the original WalMart RVing group. The purpose of this group is to discuss overnight parking of RV's at Wal-mart, K-Mart, Flying J, Travel Centers of America, Camping World, Union76 Truck Stops, Love's, Pilot Travel Centers, AmBest Truck Stops, casinos, and similar hosts that allow free overnight RV parking. We promote a voluntary standard of conduct for RV Parking, as opposed to RV Camping.
Having a solar panel can give you a lot of passive power, particularly in these days and times when modern solar panels keep charging even when in partial shade. Mounting a wind generator can also give you power to keep the house batteries fully charged even at night, if there is any wind. You may want to make your wind generator removable so you don't increase your overhead clearance height.
Complete Book of Boondock RVing:
Off the Beaten Path
Guide to Living Without Hookups
Go Power! 80-Watt Solar Charger is a high efficiency polycrystalline panel
using the suns rays to create DC power to charge the batteries. Will produce some charging power in overcast weather and provide up to 4.6 Amps of charge per hour of good sunlight. averages up to 196 Amp hours per week. It includes a 25 Amps digital regulator capable of handling up to 395-Watts of solar, all mounting
hardware to mount the panel flat on the roof, 25 feet of UV resistant cable for wiring up the solar system. Contains all instructions.
Go Power! GP-RV-80 80-Watt Solar Kit with 25 Amp Digital Regulator
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RV Wind Power 400 Watt 12V Wind Generator Back Up Power Water Proof