It seems so straightforward that it does not warrant a second thought.
A wind turbine has a rated power capacity and this should be delivered.
The reality is more complex. The maximum power a turbine produces may vary due to a number of factors.
A curtailment or derating can be applied to reduce power to meet technical or grid limitations. However, sometimes small deratings are unintentional and can be difficult to spot and diagnose. In our experience, it is surprisingly common to find one or more wind turbines in a wind farm that does not reach rated power, with deficiencies in the range of a few tens of kW. Of course, this leads to long-term production losses.
Conventional power curve analysis often does not apply all best practice guidelines, such as windspeed normalization and turbulence intensity correction, which makes it difficult for the human eye to detect such issues. Therefore, more advanced tools such as i4SEE Performance™ are needed.
It is interesting to note that overproduction can also occur, which might actually be more of a problem rather than a benefit and raises engineering concerns. Higher power, higher temperatures, and higher loading on the turbine will eat away at the remaining life of the asset and can increase maintenance costs. Overproduction can also cause a violation of the contract with the grid provider and may result in cumulative penalties per occurrence. A lack of awareness can be costly.
The end game is the same. Use best-in-class tools to regularly check turbine performance and rated power. Use persistence in following up on any deviating turbines until they are producing their exact rated power. No more, no less.
