BS PD IEC/TS 61400-26-2:2014 provides a framework from which production-based performanceindicators of a WTGS (wind turbine generator system) can be derived. It unambiguouslydescribes how data is categorised and provides examples of how the data can be used toderive performance indicators.The approach of this part of IEC 61400 is to expand the time allocation model, introduced inIEC TS 61400-26-1, with two additional layers for recording of the actual energy productionand potential energy production associated with the concurrent time allocation.It is not the intention of this Technical Specification to define how production-basedavailability shall be calculated. Nor is it the intention to form the basis for power curveperformance measurements, which is the objective of IEC 61400-12.This document also includes informative annexes with:

examples of determination of lost production,
examples of algorithms for production-based indicators,
examples of other performance indicators,
examples of application scenarios.

Cross References:IEC 60050IEC TS 61400-26-1:2011IEC 61400-1:2005IEC 61400-12-1:2005IEC 61400-12-2:2013IEC 61400-25-1:2006IEC 61400-25-2:2006IEC 61400-25-3:2006IEC 61400-25-4:2008IEC 61400-25-5:2006IEC 61400-25-6:2010ISO 3977-9:1999IEEE 762:2006