2nd generation wind turbines are better, more effective, than its predecessor, and succeed in generating more electricity with smaller wind volumes. These wind turbines incorporate two newer technologies, that make them more efficient. Self starting vertical blades and magnetically suspended bearings, which makes them superior to any other.
The self starting vertical blades provide advantages over the horizontal blade wind turbines. These vertical blades are more aerodynamic and capture wind turbulence from any incoming direction, whereas the traditional horizontal propeller type of blades need to be facing the wind and cannot capture wind currents which are vertical in nature (up or down). Vertical blades are safer and lighter, they reduce noise, are easier to handle, can be hoisted easier and blades dismantled in anticipation of hurricane wind to prevent turbine damages. They can be place on roofs tops and buildings as shown below because they occupy small spaces and need height to ensure there is no obstruction for the wind.
The magnetically suspended bearings supports the load of the rotating shaft without contact, allowing the shaft to rotate at high speed without any friction nor mechanical waste. The magnetic bearings do not require any lubrication, thus you get no contamination with an expected life of 25 years.
Both technologies put together make this particular wind turbine more effective, and generates electricity at starting wind speeds of 6 mph.