Questions

Wind turbines are very reliable and require minimal maintenance. A modern turbine would be expected to be operational about 97% of the time. Conventional generation operates at around 40% efficiency.

A figure of only 30% efficiency is often quoted. This is misleading. The turbine is designed to cope with the strongest winds, which are obviously greater than the average wind. The 30% is just the average wind energy capture as a percentage of the peak capacity. It has nothing to do with how efficient the turbine is.