Less powerful but more compact turbines are being engineered in the Bayview workshop of start-up company Blue Green Pacific, which has installed elegant 6-foot-high, horizontally-rotating prototypes on top of a windswept garage in the Castro, primarily for testing purposes.

Founder Todd Pelman said he has a list of “hundreds” of Bay Area residents queuing for the virtually soundless toys. The products will have an “emotional” appeal, like a Prius, he said.

“One of these isn’t really going to make a difference — but if there’s many, then there’s an aggregate effect,” the former engineer said.

Pelman said he hopes to start selling prototypes within a year. The company, which is in “a race” to raise money and secure a position in the emerging market, aims to mass-market the appliances for under $5,000, he said.