> The Calorius type 37 – which had a rotor diameter of 5 meters and a height of 9 meters – produced 3.5 kilowatt of heat at a wind speed of 11 m/s (a strong bre

> The Calorius type 37 – which had a rotor diameter of 5 meters and a height of 9 meters – produced 3.5 kilowatt of heat at a wind speed of 11 m/s (a strong breeze, Beaufort 6). This is comparable to the heat output of the smallest electric boilers for space heating Well, there you have it of why it's a relatively unknown tech (that I also didn't know about). The heat produced is very small for a house yet the blade still needs to be very high, making it impractical on most houses. On top of that hot water transport on long distances is a recent thing due to advancement of pipe tech which made communal version of those impossible at the time.