Testing the testers

Wind turbine

Alejandro B. Martínez Muelas is the Vice Chairman of Measnet (International Network of Wind Energy Measurement Institutes), a non-profit organization comprising the most experienced wind energy institutes from around the world, which aims to work out rules and requirements which will guarantee that high quality comparable measurements are made by its members. The non-profit is also actively participating in IECRE and, with its support, has decided to publish proficiency test reports which are and will be available for free to the whole wind energy industry. The first report is on the power performance of wind turbines and can be obtained from Measnet.<_o3a_p>

We ask him why proficiency tests are essential to ensure trust in IECRE testing and certification. (Read the full interview in e-tech.)<_o3a_p>

What are proficiency tests?<_o3a_p>

The aim of proficiency tests - assuming that we all are measuring the same wind turbine and the same wind - is to ensure that we have comparable results. What we are saying with the proficiency test report is that no matter the test lab you use, no matter who is doing the job, the results will be the same. A lab in China will give the same results as a lab in Germany or in Spain, which is in the IECRE system. Any manufacturer in the world can trust that labs in the IECRE system will provide the same results.<_o3a_p>

What does a proficiency test measure?<_o3a_p>

To be part of the IECRE system, the technical laboratories have to prove that they themselves can perform correctly and test wind turbines correctly. Proficiency tests are exercises in which the laboratories show their competency. The first report we issued is about how the laboratories can measure the power performance of the turbine (how much energy the wind turbine is generating compared to the energy already provided by the wind). But there are other tests, for instance about vibrations: will the wind turbine be capable of withstanding vibrations? There are also tests which deal with wind blades: are the wind blades strong enough to withstand the wind? These tests and many more are all part of the certification process of the wind turbine.<_o3a_p>

Why did you decide to publish this first report and why is it so important?<_o3a_p>

Measnet was criticized a few years ago because we were said to not be transparent enough with our way of working. Now we are part of IECRE which is a system comprising not only testing laboratories but also certification bodies, manufacturers and users, which are often utilities. All these stakeholders need to trust in the tests we are providing. In order to ensure trust, we decided at the beginning that some results would be made public. Everybody in the IECRE system would have to see who participated in the proficiency testing, who passed the tests and what was checked. And once that decision was taken, we wanted to go as public as possible. The document we published is especially long and complex and that degree of transparency was never reached before.