After dismantling at the quarry lake, the model was brought to a bay on the Baltic Sea, rebuilt and used in the Baltic Sea. For this purpose, the model was only slightly modified for the swimming stability, since the environmental conditions were above the design conditions. In addition, the anchoring system was adapted to the new water depth and wave environment, as intended in the nezzy² design philosophy.
The mooring system was pre-installed, the site was 650 m from land. During this test phase, three-bladed rotors were used because the test time was limited, just the rotational direction was changed to test the difference.
After the aerodynamics and wind tracking had been validated in the first test phase, the focus was now on the system behavior under the influence of waves and currents. Wind tracking was again measured under various environmental conditions and evaluated very dynamically. The tower top acceleration was measured in detail to validate the usability for all available wind turbines.
At the end of the measurement campaign, the model was hit by a storm that significantly exceeded the design parameters of the model. With a scaled wind of 72 m/s and 30 m wave height, the model was heavily challenged and survived the situation unscathed. The measured values recorded could now also be used to compare the demonstrator with the simulation results under survival conditions. After finishing the test all components are removed from the seabed, including the anchors and the communication cable.
Finally, the two-phase project approach is rated as very successful, since the influences of the environmental conditions could be considered separately and thus significantly increased the validation depth. During both test phases, nezzy² showed exceptionally good test results.