TY - RPRT
TI - Testing and Evaluation of "SafeWind" A Bird Protection System
AU - Soni, B
AU - Loske, K
AU - Lackmann, J
AB - In Germany, the expansion of the wind energy in accordance with the species protection canonly push the goals of German Energy Transition. In the present scenario, technical solutions(camera and radar) does not have sufficient scientific database on assessment of reduction ofrisk of collision of endangered species in German wind parks. Therefore, wind industry facesoperational restrictions on existing wind turbines as well as reduced access to onshore windpotential area.In beginning of 2018, WestfalenWind GmbH and Lackmann Phymetric GmbH took the initiativeto test and evaluate SafeWind - a camera-based automated system by Biodiv-Wind SAS,France in their wind parks. At Lichtenau Hassel Wind Park, three SafeWind systems areinstalled at location (WEA 9, WEA 11 and WEA 13) and have been in operation sinceAugust 16, 2018. The SafeWind system works on principle of real time detection of flying objectwithin intrusion area and triggering of regulation control of wind turbine, when the target iswithin the threshold limit. The aim of the test and evaluation of the SafeWind system was tocreate the decisive scientific database for its acceptance as an adequate mean to reduce therisk of collision of bird species like – red kite and black stork.For uniformity in interpretation of the results, the evaluation protocol was adapted as perguideline published by KNE. In 2019, Dr. Karl Heinz Loske conducted the field study (betweenMarch and October) at Lichtenau Hassel Wind Park as an independent expert, Ph.D. Ecology,and submitted the report. The report from the expert is used as an input for the evaluation ofthe SafeWind system. Due to practical constraint on the field observation, only two windturbines, WEA 11 and WEA 13 are considered for the study. The limiting parameters for thedetection capacity (i.e. detection range) and regulation control (i.e. reaction range) weredetermined through the repeated Robird drone experiment. The dataset for the estimation ofspecies-specific acquisition rate and collision risk probability were generated by applying thelimiting parameters to the field observation data (LRF data) from Dr. Loske. In the dataset, itwas assumed to consider the data between the installation height of camera and tip of the rotorblade (12 o’clock position) of respective wind turbines.The detection range and the reaction range around the wind turbine were evaluated as 270 mand 172 m for red kite, and 337 m and 215 m for black stork from the Robird experiment. Theacquisition rate is percentage of flying tracks detected by the SafeWind system out of all theflying tracks within detection range of respective species from the LRF data. At the rotor altitudeof the wind turbine within the detection range, the acquisition rate for red kite is maximum, 84%at WEA 11 and 93% at WEA 13. In case of black stork, it is 100% only with one wind turbine(WEA 11) but may not be meaningful due to less number of the observation points. Below theTesting and evaluation of SafeWind – a bird protection system at Hassel Wind Park 3rotor altitude of the wind turbine and within the detection range, the acquisition rate for red kiteis comparatively lower, 83% at WEA 11 and 76% at WEA 13. In general, the acquisition rateswere expected to reduce gradually outside the detection range. However, this reduction isneither systematic nor homogeneous and linear. For example, the acquisition rate for red kiteis surprisingly increasing with the distance in case of WEA 11 and reach up to 88% in thezone 2 (270 m – 300 m). The hypothesis is that the other factors than distance, altitude andposition of bird may influence the acquisition rate. While investigating the non-acquisitions, itwas observed that the topography and kind of background (vegetation, other wind turbines,deep dark sky) around the wind turbine may influence the acquisition rate. The topography andthe background have a relation with the installation height of camera (In our case, theinstallation height was selected due to the turbine-specific constraint). The site-specificadjustment on the installation height of camera thus can improve the acquisition rate of thesystem.The collision risk probability is the measure of effectiveness of reaction of the SafeWind systemfrom the reaction range. A worst-case scenario, direct flights of each track of red kite at theiraverage speed from the reaction range distance towards the wind turbine rotor and theirinability to anticipate the moving object, were assumed for the calculation of the collision riskprobability. When the time taken to reach to the rotor is less than the time needed to bring therotor to the safe rotational speed (idle speed = 50 kmph of blade tip speed), respective tracksare declared, hypothetically, as a collision with the rotor. Considering the reaction rangeadopted for this experiment, the collision risk probability for red kite is determined as 9% atWEA 11 and 12% at WEA 13. These probabilities of risk of collisions appear highlyoverestimated. When the reduction factors like varying operational speeds of the wind turbine,biological avoidance behaviour of red kite can eliminate the overestimated risk of collision.Based on learning from the SafeWind recorded videos, the red kite has obvious anticipationbehaviour while passing through the rotor. For quantifying the anticipation behaviour, birdvehiclecollision studies for turkey vultures (DeVault, 2014) are referred which resulted inreduction of probabilities to 3% at WEA 11 and 8% at WEA 13 due to anticipation behaviourof birds of prey below 90 kmph speed of the moving object. Moreover, empirical data of BirdSentinel from Biodiv-Wind shows that collision events of red kite in France (n=7) and inGermany (n=1) detected by the SafeWind up to now were only recorded when blade tip speedwas above 130 kmph. Considering this, the collision risk probability in our case is 0%. Indeed,the collision of any bird species is reported neither during the study period nor from the daythe SafeWind system is in operation.To sum-up, the use of the SafeWind system at wind turbines, which has the maximumacquisition rates (84% at WEA 11 and 93% at WEA 13 in the critical risk of collision zone)within the detection range and the low theoretical collision risk probability (9% at WEA 11 and 12% at WEA 13) within the reaction range for red kite, shows the significant reduction in therisk of the collision. Despite the limited numbers of observations for black stork, the reductionin the risk of collision is also applicable. Such system can also reduce the risk of collision forother species like common buzzard, black kite and kestrel found around the study area. At last,the outcome of the evaluation will enable the authorities to decide on accepting the SafeWindsystem as an adequate mean to reduce the risk of collision of the impact sensitive bird speciesfrom the wind turbine.
DA - 2020/08//
PY - 2020
SP - 38
PB - Ing. Büro Landschaft & Wasser
LA - English
KW - Wind Energy
KW - Land-Based Wind
KW - Fixed Offshore Wind
KW - Floating Offshore Wind
KW - Collision
KW - Bats
KW - Birds
ER -