End of Warranty Requirements for Wind Energy

According to the Retrofitting, Reliability & Repowering report 2012 the approximate sum covers wind farms in the UK, US, Germany, Denmark, China and India between 8 and 20 years of age and either entering or approaching post-warranty status.

China leads the way with over 40,000MW capacity followed by the US with 37,000, Germany with 15,000MW and the UK’s 4000MW.

The report, which combines primary and secondary research with interviews with industry engineers and developers, assesses how wind farm operators can best measure the reliability of their operations post warranty and if found lacking what they can do to boost energy efficiency and cost effectiveness.

The merits of retrofitting, essentially improving an existing turbines efficiency and capacity by fitting new technology such as better grid connections or the latest blade designs, and repowering, decommissioning an existing turbine and building a more modern and powerful version, are considered.

The report suggests that operators need to have a better understanding of the failures that occur when a turbine warranty ends and the impact paying for their repairs has on their productivity and profitability. Only then can they best judge which strategy to take to improve yield.

According to the report 42% of events after a warranty ends are related to component failures, whereas 21% of the issues relate to control system failures. The cumulative number of failures in a year for a single wind turbine is 2.43 with the most affected parts being the Electrical System (0.57 failures per year) and the Electronic Control (0.43 failures per year). The most reliable component is the drive train.

The component causing the biggest loss of downtime, lethal to site profitability, at an average of 6 days is the gearbox.

The likelihood of failure dramatically increases in older installations and therefore the repair costs will rise in proportion. The two factors together, the report maintains, enormously enhance the potential profitability of repowering or retrofitting old technology.