Identifying risks before construction begins - How drones make wind energy projects more efficient in planning

Benedikt Krause: The Occasions are quite different. Often it is about suspected explosive ordnance on planned wind turbine sites, crane parking areas, access roads or cable routes. A second major area is archaeological questions, which are actual start of construction. In addition, there are surveying tasks, for example example if current orthophotos, terrain models or as-built data for the further planning is missing. Our use is always particularly useful when larger areas must be investigated and a resilient data basis is needed.

Benedikt Krause: On In most cases, our support is provided at an early planning or approval phase. If possible explosive ordnance contamination, archaeological suspected areas or special features in the terrain are known at an early stage, the planning. This is usually clear easier and cheaper than if such issues were only discussed during construction emerge. Especially in wind projects, unresolved areas can otherwise quickly become delays in access roads, crane parking areas or foundation work.

wind-turbine.com: What exactly does UAV geomagnetics do in a wind energy project?
Benedikt Krause: At of UAV geomagnetics, we use very sensitive magnetometers to measure the smallest Changes in the Earth's magnetic field. Search for explosive ordnance detection we look for magnetic anomalies that point to ferromagnetic objects in the subsurface. . The measurement data is recorded georeferenced, then evaluated and conspicuous areas documented. In archaeological prospection magnetic differences, for example, indicate backfilled trenches, former settlement structures or other soil changes. It is important to us to classify: We do not generate a photo of the subsurface, but measurement data that can be used professionally must be interpreted.

wind-turbine.com: In addition to geomagnetics, photogrammetry plays an important role. What is this data used for in wind energy projects?
Benedikt Krause: The Photogrammetry is a very practical tool for many wind energy projects basis, because it allows you to see the current state of an area in great detail. . From the drone images, we create Depending on the task, for example, high-resolution orthophotos, point clouds as well as terrain and surface models. Customers use this data at for the planning of access roads and crane parking areas, for terrain profiles and elevation information, for area and mass determinations or simply as reliable documentation of the initial state. Especially when several planners, construction companies and public authorities, a joint up-to-date Data basis very helpful.

wind-turbine.com: What are the practical advantages of a drone-based investigation compared to classic ground-based methods?
Benedikt Krause: The The biggest practical advantage for us is the combination of high area coverage, high data density and very little interference with the Area.
Large areas can be comparatively be examined quickly without the area being walked on or must be driven on by vehicles. As a result, soils, vegetation and existing structures. Areas with vegetation up to approx In many cases, hip height can still be flown over and examined.
At the same time, georeferenced data that can be directly integrated into other GIS, planning and evaluation processes. Especially in the case of difficult-to-access, sensitive or extensive areas, this is a significant advantage over classic ground-based methods. The drone does not replace any classic procedure. Its strength lies in particular in the fact that to examine large areas efficiently and without contact and to examine them on this possible follow-up measures in a more targeted manner.

Benedikt Krause: Especially the drone-based investigation of larger project areas is interesting, multiple wind turbine locations, longer access roads or cable trays and everywhere where a classic comprehensive examination takes a very long time or personnel-intensive. An additional advantage is Areas that are difficult to enter or drive on. Since no area-wide inspection is required for the measurement, sensitive areas, agricultural areas or terrain with higher vegetation can be examined without causing unnecessary damage. . Vegetation up to about waist height is also is generally not an exclusion criterion for aerial surveying. In the case of narrow construction time windows, repowering projects or complex areas, the process can therefore be be particularly interesting. Basically, the larger, the more difficult to access or more sensitive an area is and the more important it is to have an early data basis for further planning, the stronger the advantages of the use of drones.

wind-turbine.com: Conversely, are there situations in which a drone-based investigation is not the first sensible step?
Benedikt Krause: Not every area is automatically a sensible drone use. If an area is very small, reliable and up-to-date expert reports are already available or a different procedure is provided for or preferred by the authorities, another way may make more sense. Especially in the field of archaeological prospecting, the use of geomagnetic techniques is carried out regionally and by the competent authorities. This also applies to some extent for the drone-based implementation of geomagnetics. Although we have been familiar with the methodology in many projects achieve very good results, it is not always area of responsibility is equally established or used as a method of investigation . That is why we agree at an early stage which methodology is suitable for the respective project makes sense from a technical and regulatory point of view. In addition, the specific conditions on site play an important role. Larger quantities of scrap, metallic Backfills, fences or other strong sources of interference can cause geomagnetic measurements. Very dense or high vegetation can also have a significant impact on the according to the task. That's why we always check in advance whether the process is suitable for the specific area and meets the desired knowledge.

Benedikt Krause: In the first step, we need the project area, ideally as SHP, KML, DXF or comparable geodata, as well as the task and existing documents. Then we check the area, the framework conditions and possible disruptive factors and plan the deployment. On site is carried out systematically and then processed and technical evaluation of the data. Which documents the customer will have in the end depends on the performance. This can be, for example, orthophotos, point clouds, terrain or surface models, maps, measurement data and results reports. In the case of geomagnetic surveys, the relevant anomalies accordingly. The processing time depends heavily on area size and depth of evaluation. For normal project sizes, we speak after the flight often from a few days to about two weeks; with very large or complex projects.

Benedikt Krause: Very questions often arise about the possible area performance, accuracy and depth of detection. Customers also want to know what requirements the area must meet, whether it must be mowed beforehand, how strongly vegetation or existing infrastructure influence the measurement and which data formats they will receive in the end. In the case of explosive ordnance detection, It is also important to explain that the actual detectability of many factors and we can only release it up to a maximum depth of five meters. It is also frequently asked whether the drone. We use it where it makes technical sense and brings a real advantage.

wind-turbine.com: Finally, a little more personal: What What is the appeal of this work for you?
Benedikt Krause: For I'm particularly excited that we can combine modern drone technology with very specific problems in large infrastructure projects. In the end, it is not a question of creating a drone, but to provide the customer with information at an early stage, with which he can plan better. If we make risks visible, before they become a problem on the construction site, thereby saving time or unnecessary Saving effort, the benefit of our work can be seen very directly. This is exactly what makes the topic interesting for me.