Aren't there turbines with a vertical shaft, which don't need a large tower? I saw one a few months ago, built especially for city rooftops where you don't have

Aren't there turbines with a vertical shaft, which don't need a large tower? I saw one a few months ago, built especially for city rooftops where you don't have that much space and generally need something not that expensive. You'd still have the problem of turbulences though (i.e. non-optimal performance generation)