Vertical-axis wind turbines have blades that spin around the main pole, instead of using a propeller that sticks out to the side. Mariah Power’s Windspire is the first vertical axis turbine that can start in low winds without a boost from a motor or inefficient scoops or wings.
Vertical-axis wind turbines are usually quieter than traditional propeller-style turbines. The Windspire produces just 45 decibels, a little higher than an ordinary indoor room.