I was going to say the same - there was a big fad for building-top wind generators and then everyone figured out that the airflow over a building is really turb

I was going to say the same - there was a big fad for building-top wind generators and then everyone figured out that the airflow over a building is really turbulent, which makes it pretty shit for power generation. Ask anyone who sails; trees and buildings shield a lot of wind out to surprisingly far away. The reason the big boys work well is because they are much higher above the ground where the wind is stronger and more consistent. That's also why companies are trying to make kite and blimp based generators work. Only place I've seen the rooftop turbines work was at an airport where the giant open space around the terminal buildings means winds are more even and lower to the ground. It feels like off-grid people mostly use it as a supplement for the stormy bouts where winds are often strong when solar yield is low...or as a backup in case their solar system breaks. They're happy if they meet the needs of their fridge, for example. Modern fridges use an average of less than 100W; lower if they're not self-defrosting.