I've commented on this topic before in this group and my experience is different than most of the current responders. This topic gets about the same attention as anchors. I find it curious that the cost/benefit equation being used for solar panels does not include the $10,000 arch installed in the stern.
We installed an Air Breeze windgen (with aftermarket propellers) just above our radar on the mizzen. In 15 kts it generates 10-12 amps as long as the wind keeps blowing.
Our solar panels do not rotate to follow the sun so they only produce measurable amps 6 hours a day in cloudless skies. We've almost completed a circumnavigation and we've seen an awful lot of cloudy days and we've been in a lot of anchorages where the wind blows all day and all night.
Our Air Breeze is very quiet. When we are in an anchorage, it seems we can hear everyone else's windgen but not our own. The Air Breeze has a ground switch that acts as a brake and allows us to hoist the mizzen stay sail without incident.
I'd be happy to answer any questions you might have about our windgen.