Before manufacturers can bring new wind turbines to the market, they need to be certified. When wind farm operators suspect under performance of a wind turbine, they need an independent party to validate this assumption. When wind farm developers need to build a solid business case, they need a reliable wind resource assessment. TNO support the wind industry with standardized measurements being ISO 17025 accredited and IECRE approved.


The wind industry is constantly looking for the highest quality and most reliable measurements. These are needed for instance to certify a new wind turbine prototype, to validate the performance of an operating wind turbine, to build a solid wind farm business case, etc. High quality measurements are achieved through standardization, which assures that the applied methodology is accepted, complete and repeatable. The International Electrotechnical Commission (IEC) issues standards relevant for the wind industry (IEC 61400 series) and TNO works according to these standards.


To assure that TNO works according to the IEC standards, it is ISO 17025 accredited by the Dutch accreditation council (Dutch: Raad voor Accreditatie (RvA)). Also, TNO is an acknowledged IEC Renewable Energy test laboratory (IEC RE TL) for power performance and mechanical loads. This new, international framework assures the technical competences of the participating testlabs through peer assessment and operational documents in addition to the IEC standards. TNO is founding member of MEASNET, a network of measurement institutes. This organization is a forum for in-depth discussions about technical issues and organizes round robins on the standardized measurements.

Power performance and Mechanical loads

TNO carries out power performance assessments in the certification process and for validating perceived under performance of operational wind turbines. Relevant standards are the recently issued IEC 61400-12-1; 2017 (edition 2), describing the use of meteorological masts and ground based LiDARs, and the IEC 61400-12-2, describing the use of nacelle anemometry. Additionally, there are Operating Documents from IECRE WE-OMC, guidelines from MEASNET and from the ‘Fördergesellschaft Windenergie Technische Richtlinien (FGW TR) Teil 2’ and ‘Teil 5’, particularly for the German market. TNO is experienced in calibrating nacelle LiDARs and using them for power performance, which will soon to be included in the IEC standards.

Mainly related to the certification process, TNO carries out mechanical loads measurements according to IEC 61400-13; 2015 to assess the structural response of the blades, main shaft and tower to the ambient wind conditions.

Meteorological measurements and LiDAR calibration

For assessing the local wind resource with respect to (offshore) wind farm development, TNO carries out wind measurements. Meteorological mast set-up, installation and measurements are performed according to IEC 61400-12-1. Equivalently, ground based LiDAR and floating LiDAR measurements are performed following the calibration specifications from IEC 61400-12-1 (Annex L) and the Carbon Trust OWA roadmap for the commercial use of floating LiDAR systems, respectively.

TNO is your trusted partner for measurements in wind energy.

If you are interested in dedicated wind measurements, please contact us.

Jan Willem Wagenaar

Innovative methods for wind measurements

TNO supports commercia in the wind energy industry with research and innovation, in order to achieve the greatest possible return from offshore wind energy. Read more

Towards large-scale generation of wind energy

The Dutch government has agreed with the energy sector that the near future will already see that energy generated from sustainable sources will be a substantial share of the energy mix. The future Dutch energy... Read more

Renewable electricity

In order to phase out the use of fossil fuels and raw materials in the long term, households, services, industry and transport will have to largely or even completely switch to renewable electricity.... Read more


Dr Jan Willem Wagenaar