Increases in wind turbine size
The average turbine size installed each year in the leading wind power countries increased steadily from 145 kW in 1989 to 2,158 kW as of May 2011.Turbines models with a larger capacity are penetrating the market to a larger extent while the popularity of smaller turbine models is waning. Larger turbines have lower operating and maintenance costs and
lower grid connection costs per MW and produce more megawatts of electricity per acre. The maximum size of turbine models on the market increased from 30 kW in 1980 to 6 MW in 2010, roughly equating to a doubling and tripling of the capacity of turbine models every five years since 1980. As repowering becomes more commonplace, a smaller number of low kW models are likely to remain in operation. Two German manufacturers, Enercon and REpower, produce the three largest commercial turbines in current operation.
Larger capacity wind turbines are under development and all the main players are involved to secure a share of this growing market, especially for offshore wind projects.
Most installed turbines have capacity under 1 MW, but the introduction of more advanced systems with larger rotors has moved the industry towards higher capacity machines. However, bigger is not always better, as operating parameters and performance are generally better understood with machines in this lower capacity segment.
Turbines of 1 MW to 1.49 MW turbines have carved out a niche in Europe. However, the industry’s trend toward multi-megawatt machines has reduced demand as greater output at the same sites can be captured with 1.5 MW and larger models. The segment has now dropped to under 500 MW of annual installations as suppliers seek to push their larger platforms.
The installation of 1.50 MW to 2 MW turbines peaked in 2002 but has generally levelled off at around 1.5 MW in the past four years. This segment saw a major drop in demand from over 30% to less than 20% of installations between 2004 and 2005, as leading suppliers and new entrants pushed 2 MW and larger models into serial production. The 2 MW class is sometimes referred to as the world’s first commodity-type wind turbine and the 2.5 MW turbine categories may soon qualify for commodity turbine status.
Since 2005, 2 MW and larger turbines have become virtually standard in Europe. This size of machine jumped to over half of total installations in terms of megawatts. The 3 MW class has a large number of suppliers. This surge to larger sized turbines continued in 2006 as the amount of MW installed in turbines this size pushed well past 5 GW. While 2007 saw the segment hit more severely by component shortages, Europe continued to rely on these larger turbines for the bulk of its installations.