Conservative estimates suggest that at least one-quarter of a million wind turbines are currently installed worldwide. In the next four years, the global wind-turbine market is expected to add 278 GW of onshore and 44.3 GW of offshore capacity.1 This equates to at least 100,000 3-MW wind turbines.
With such growth in renewable energies, and power input to national electricity grids, the reliable operation of wind-turbine (WT) installations is the subject of significant research by industry and government bodies. Quantitative studies of WT reliability have shown that reliability has increased over time.