Urban Inter-Building Wind Power WindStep Prototype: Vertical-Axis Turbines Between Two Buildings

WindStep, jointly released by TU Delft's Faculty of Architecture and the Urban Planning department at UrbanWind, is a distributed wind power solution that installs vertical-axis turbines between urban buildings. The system installs vertical-axis turbines on skybridge structures between two adjacent buildings, harnessing the canyon wind unique to urban streets to generate continuous electricity.

The core innovation of WindStep is the vertical-axis wind turbine. Traditional horizontal-axis turbines need to point into the wind and occupy a large footprint, making them unsuitable for urban environments. WindStep uses a vertical-axis turbine (blades rotating around a vertical axis), which can receive wind from any direction and does not require a yaw system. At the same time, the turbine is equipped with active variable pitch control, which adjusts the blade angle based on real-time wind speed and can still generate effectively in weak wind conditions of 4 meters per second.

The pilot was conducted in the Katendrecht neighborhood of Rotterdam, the Netherlands. The system installed 8 WindStep vertical-axis turbines on 4 pairs of adjacent buildings, each with a rated power of 15 kilowatts. Nine-month operating data show that a single WindStep installation (2 turbines) generates about 36,000 kilowatt-hours per year, equivalent to the annual electricity consumption of 8 ordinary Dutch households. The total system investment is about 450,000 euros, with a payback period of about 7 years based on Rotterdam industrial electricity prices. Eva van Loon, founder of UrbanWind, said the company has launched a new round of deployments in Amsterdam and Utrecht, with the goal of installing WindStep in 50 Dutch neighborhoods by 2027.