This issue, we are taking a side trip in the renewable energy realm to explore the production of electricity from wind sources.
Wind power has been around for centuries, what's more picturesque than a Dutch windmill? Using wind to produce electricity began in earnest in the US in the early 1930's, when many small stand-alone wind systems were installed in rural farms and residences to charge the batteries necessary to run the instruments of the latest electronic craze, radio. Wind generators ranging in size from 100 watts up to several thousand watts were marketed and installed, bringing new power and conveniences to remote homesteads across the country.
The push for rural electrification in the late 1940's and 50's put a quick end to the growing industry of wind generator manufacture, as most grid power companies required the removal of existing wind generators as a condition to connection of service. Many perfectly functional wind plants were decommissioned, often times by toppling the towers they were mounted on with the generators still in place.
A revival of interest in wind energy in the 1970's and early 80's brought many of the more carefully removed machines back into service, as wind power hobbyists and aficionados scoured the barns and garages of the country looking for retired generators. The Jacobs 32 volt, 1,500 watt wind plants are still in great demand, and one can also find old Winco Winchargers in service all over the country.
Today, wind generators are manufactured using modern materials and computer designed airfoils and electronics. Interest in utility-scale wind power is on the rise, and rows of huge machines are frequently installed on ridge tops, where a significant quantity of power can be harvested and fed into the utility grid.
Traditionally, mobile installations of wind generators have been mostly limited to sailboats, but there is no reason that you couldn't install a small system on your house truck or bus. Wind power is the lowest cost per-installed-watt of any renewable energy source, only about 20% of the cost of photovoltaic modules. Of course, you do need a good source of wind, otherwise the investment may not be worth exploring.
Generally, a wind generator is installed on top of a tall tower, which places it in the greatest supply of 'clean' wind, that is, wind that has no turbulence produced by obstructions such as trees, buildings, etc. Of course, a 60-90 foot tall tower would be rather inconvenient to carry around and erect when you are traveling in a vehicle, so you will need to compromise and construct a mount that is as tall as can be made, but still collapsed enough to store away for the road. Here's where things get really tricky...
By nature, wind electric machines produce vibration. Even a very well-balanced machine will experience vibration caused by wind turbulence, bearing noise, pitch and yaw, and dynamic imbalances caused by the rotating blades shifting position to track changing wind directions. For this reason, it is usually a very bad idea to mount the generator on your roof, or have it connected in any way to the structure of your living space. Any vibration will make itself known immediately, as your bus will shake, rattle and roll with each changing of the breeze.
What to do? Well, for a temporary installation, I favor a steel plate that can be driven over by a tire, allowing the vehicle's weight to act as ballast to keep the tower upright. A socket on the plate mates with the base of the steel pipe that forms the tower. Any vibration will be dampened by the tire and contact with the ground or pavement. Obviously, the tower may only be 15 feet or so in height, but when parked at an exposed windy location such as the ocean shore or a bare mountain top, you should be able to harvest a wealth of free energy. Unlike solar electric sources, wind energy can be available 24 hours a day. And before you ask....NO, it is NOT possible to use the wind generator to recharge your batteries while you drive down the road!
Should you consider constructing your own wind electric generator, be advised that it is not as easy as might be expected to construct a high-efficiency, well-balanced and reasonably functional wind plant. Considering the prices of smaller wind machines these days, your efforts might be better put to use earning the purchase price of a new or used commercially-made machine.
In any event, the sight of a spinning propeller atop your rolling home is sure to make you the star attraction wherever you roam. Nothing brings attention faster than kinetic sculpture.