Standards Development

Scope

The scope of this standard is the assessment and reporting of site-specific wind conditions and energy yield for wind power plants.

This includes the following key scope components:

• all measurement, analysis and evaluation steps including data analysis, modeling, loss assessment and net energy production estimation for wind power stations as required to make the results reproducible and traceable to national standards;

• definition of documentation and reporting requirements to make the results traceable to national standards;

• definition of a digital exchange format for energy yield reporting to facilitate efficient information exchange;

• a standardized approach to the uncertainty quantification of a site-specific energy yield assessment (EYA).

The standard will include in its scope the assessment of site-specific wind conditions and related parameters to determine the potential energy at a site.

Specifically, the suitability of methods already in use by the wind industry for the stated purpose should be discussed and agreed. These methods include but are not limited to data processing, long term correction such as MCP (Measure Correlate Predict), power curve modeling, wake modeling, site optimization and use of reanalysis data or any other currently applied methods known to the experts of the project team. Areas where scientific consensus in lacking will be included as informative annexes.

Scope limitations:

According to IEC 61400-1 the site-specific conditions can be broken down into wind conditions, other environmental conditions, soil conditions and electrical conditions. Furthermore, each condition can be subdivided into normal and extreme conditions as far as they affect the wind flow. All of these site conditions other than site specific wind conditions and related documents are out of scope for this standard.

Purpose

The market relevance is that the energy yield assessment is one of the key steps in establishing a wind power station that is currently not standardized. The large variation in approaches used by different actors in the wind industry, the low quality of equipment sometimes seen as well as the lack of traceability observed in certain situations leads to a high uncertainty on the expected potential energy for a given site and a high risk to potential developers and investors. If not adequately characterized, this high risk can directly impact the competitiveness of wind energy projects in the market. A common approach to the methodology and reporting requirements will provide a common basis for Energy Yield Assessment (EYA) for developers, OEMs, independent engineers, certification bodies, end users, and financial institutions.