A shrouded rooftop turbine, built for city wind.

The building does half the work

Wind hits a building and piles up on the face. It spills up and over the roof, faster than the wind out in the open. Faster wind means much more power. Power scales with the cube of speed: double the speed and you get eight times the power. The equation is P = ½ρAv³.

The shell does the rest

Fins on the shell collect that rooftop wind and funnel it into the blades. The blades sit inside the shell, so people and wildlife are not next to an open rotor, and the shell does not flicker the way open blades do. The idea is old and well tested in fluid dynamics (a venturi). Turning it into a reliable rooftop product is the work still in front of us.

What is shown, and what is not

A prototype has shown 2 kW. The design target is 6–13 kW. The commercial unit is expected to be 10–15 feet tall. A later home unit would be about 4–5 feet tall. Final materials are not chosen. Contenders are carbon fiber, sheet metal, fiberglass, and molded plastic for the smaller unit.

• Efficiency. The shell, blades, and generator still have to turn this airflow into real electricity. That depends on the engineers building it.

• City wind does not come from one direction. The turbine has to keep working when the wind shifts.

• Independent tests. A shrouded turbine can look like it beats the usual wind-energy limit. It only counts after a qualified third party measures it. Certification (UL, IEC, SWCC) comes with that.

Where this sits in the plan

Late-stage R&D. One more design pass, a commercial-grade prototype, then pilots and certification together. Pilots are planned toward the end of 2026. Nothing is for sale yet. Specs will be published when they can be stood behind.

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