Research to support the energy transition: Metrology for the expansion of wind energy in Germany

The expansion of sources of renewable energy requires e.g. the designation of suitable areas for wind turbines (WT) and photovoltaics installations. Tall WT may interfere with terrestrial navigation and radar installations due to reflections of the electromagnetic waves. They may also emit infrasound noise. These issues may pose restrictions on building permits of WT. To be able to evaluate and score the profitability of onshore WT locations, the prevailing wind direction and speed need to be assessed up to 250 m height. As the nacelle of WT are installed at 150 m up to 250 m offshore, maintenance and repair of shafts and gearboxes are difficult to implement and costly. The quality and mechanical precision of manufacturing of WT parts are therefore essential for a long lifetime and a good return-on-invest. PTB as the National Metrology Institute of Germany has successfully completed research projects that address these issues. This paper describes each topic and gives an overview about the infrastructure such as the Wind Competence Centre (CCW) at PTB, the results of the projects, and their contributions to the expansion of renewable energy.