Fact 1: Awindmill converts wind energy into electricity primarily by using mechanical energy.

Fact 2: Wind speed is important for wind energy.

Given the two facts above, answer the question "What converts more wind into electricity?" with the following options: 
- bicycle
 - adding heat
 - stagnant wind
 - slow wind
 - engines
 - wind speed
 - satellites
 - no wind


 

      wind speed   