They sure are neat. You see them on many sailboats. This Rv'er uses a 12 Volt/200 Watt AirBreeze Wind Turbine, the most powerful wind generator in its class.
I am in the process of adding a wind turbine to my setup. Instead of something as large as the AirBreeze, I am evaluating 2 Vertical Air Turbine designs - Ampair Dolphin and a Four Seasons VAT. They do not produce as much power as the standard design but since my power requirements are low (all LED lighting
, a satellite radio, and a security camera) it with the solar
panels will provide more than enough power to keep my 3 batteries topped off. I like the VAT design because of its small footprint and ease of assembly. No fancy setup. Just mount the turbine on the top of a 3 piece 2" OD aluminium flag pole strapped to a mount on the rear bumper.