The U.S. Department of Energy Wind Program and Sandia have been working with the International Electrotechnical Commission (IEC) Committee on Wind Turbine Availability to develop three specifications for IEC-61400-26―the standard that addresses wind turbine and wind-plant availability. The first specification is on the definitions of operating states and availability conditions and was published in 2011.
The second specification is on time-based energy production and it defines a methodology for production accounting for differing operational states of a wind turbine, considering internal and external conditions. For example, it defines accounting for potential production, actual production, and lost production with determination and example verification scenarios. The second specification has been completed and approved and will soon be published.
The third specification in this series is for production for a full wind-power station, including the balance-of-plant (BoP) components of energy-collection systems, substation and interconnection, and provisions for the human (functional) element of operations and maintenance. Based on the Sandia Continuous Reliability Enhancements for Wind (CREW) team’s observations and experience, common mode failures will affect multiple elements of the wind-power station’s BoP turbines. Although the BoP does not generate power, its failures adversely affect both time and production-based availability. These failures impact the BoP’s role in electricity transmission and the turbines’ dependency on the nonturbine components.
This work will lead to standardized and mandatory reporting metrics for full wind plants when the technical specifications are invoked as a standard and/or requirement. These standards help to define requirements to support clear understanding of contract terms for performance of turbines and wind plants. This is achieved by providing an information model specifying how time designations shall be split into information categories. The accompanying illustration and table identifies the information model accounting for time, as well as measured and calculated energy.
IEC 61400-26 identifies a common basis for information exchange on performance indicators between owners, utilities, lenders, operators, manufacturers, consultants, regulatory bodies, certification bodies, insurance companies, and other stakeholders in the wind-power business. It is used to help define requirements to support clear understanding of contract terms.