This guy's vertical turbine is a piece of junk... way too many moving parts to survive for any length of time. It also wouldn't survive a winter with snow and ice building up on it.
I've been researching wind turbines for about 5 years now. Here in Michigan, our 12kW solar array provides more power than we can use during the summer, but during the winter, its a horror show.. barely enough juice to run the kitchen let alone the entire house. Thing is, it's always windy here in the winter and putting up a wind turbine just for the 4 months we need it has been a dream of mine for a while.
In all my research, I've pretty much learned exactly what's been discussed in this thread.. Any small wind turbine you buy on the internet like Amazon is going to be a complete piece of crap, and if you want one that will actually work, its going to run $30k.
Then I found this on youtube.. The video I posted (below) is the condensed version, click his channel and you can watch every step of the build. This is a heavy duty wind turbine that will last a couple decades, and one that could be repaired if needed.. But as the saying goes, there's no free lunch... this guy put a boat load of work and effort into building this thing.