Embedded computer technology for wind turbines aids bat protection

However, critics fear that the expansion of wind farms will be at the expense of nature. With a solution based on embedded computing technology from Kontron, Fleximaus GmbH is building a bridge between wind power and species conservation.

Wind and solar energy are among the most important renewable energy sources. In addition, biomass and hydropower make a valuable contribution to sustainable energy supply. Wind energy currently plays the leading role in Germany in the expansion of renewable energies. In 2018 the capacity of wind turbines installed on land was 52.5 gigawatt hours.

Added to this were 6.4 gigawatt hours from offshore parks installed at sea. With a total electricity generation of around 111 terawatt hours, wind turbines account for 18.6% of Germany's gross electricity consumption. Although the expansion of wind power plants is currently stagnating, plans of the German government envisage that by 2030 significantly more capacity from wind turbines will be on the grid.

However, the expansion of wind power plants is also controversial, as nature conservationists fear for the preservation of rare animal species. Bats are particularly being focused on. There are almost 1,000 species worldwide, 24 of which live in Germany and are almost completely subject to protection. Their existence is endangered on the one hand by climatic changes and on the other hand by humans.

For example, the ‘Bund für Umwelt und Naturschutz’ (BUND), a German community engaged in nature protection, writes in an online report that the bats in Germany suffer above all from intensive forestry, agriculture and road traffic. Additionally, the expansion of wind power plants also poses a threat to this species.

Species protection and economic efficiency under one roof

Fleximaus, a company based in Schillingsfürst in central Franconia, has developed a solution that allows bats and wind turbines to coexist. "We feel committed to our homeland as well as to environmental protection and species conservation," explained Jochen Rößler, managing director and founder of Fleximaus GmbH. "Especially the protection of domestic bats and the economic use of wind farms is of central importance to us".

For this reason, the Franconians developed a permanent and automated function monitoring system to optimise the operation of wind turbines. Using sensors, the Fleximaus-solution is able to analyse current environmental conditions that influence the hunting behavior of bats. An essential component is also the behavioral pattern of the animals calculated by experts. This includes, for example, the likelihood of flying bats, because bats hunt mainly at night, with low wind speeds and relatively high temperatures. In addition, numerous other empirical values from experts are also included in the implementation.

Sensors and algorithms optimise the wind farm

The Fleximaus-solution is based on intelligent software that is able to evaluate the environmental conditions detected by sensors and use this data to effectively control the wind farms in order to drastically reduce the dangers for hunting bats.

The evaluation of the probability of flight activity of bats is reliably determined by gondola monitoring. The sounds of the animals are recorded with special microphones below the gondola of the turbine. Trained biologists can later use the recorded sounds to determine the respective bat species (or other flying animal species) and distinguish these sounds from interference frequencies of the wind turbine. The sounds are then compared with the real environmental conditions at the wind farm and assumptions can be made in regard to the time of year, time of day and conditions under which the probability of flying bats is very high.

The so-called 'mowing shutdown' to protect birds of prey can also be implemented. The 'mowing shutdown' is a legal requirement for wind turbines in agricultural regions where the red kite has its hunting grounds. If mowing or tillage is carried out within a certain radius around the wind turbine, the turbines must be switched off. The reason: mowing frightens meadow- and field inhabitants, which in turn attracts their predators, such as the protected red kite. The high wind turbines are a deadly danger for the flying predators. Therefore they have to stand still during mowing.

Automatic protection during foraging

The monitoring system of the wind farm is informed by the software specifically which wind turbine has to be switched off at the moment in order not to endanger the protected animals during the search for food. The documentation of the data is done directly in the industrial PC, but is redundantly stored on a server and is documented here unchanged in a second database, in order to avoid data loss even in case of power failures or overvoltages.

"In addition to reliable bat protection, operating companies of southern and central German wind farms can demonstrably reduce their yield losses by up to five percent measured on the respective annual yield with our solution, as the time windows for shutdowns are considerably smaller due to the exact calculations. The losses due to shutdowns have very often been significantly underestimated in recent years. With the patented ideas of Fleximaus GmbH, species protection and the economic operation of wind farms can now be reconciled," added Rößler.

Based on an intelligent algorithm and the use of suitable sensors, the tool automatically decides whether to operate or shut down the wind turbine generator (WTG). Among other things, the algorithm also automatically implements the so-called "night tenth".

In bat protection, the term ‘night decade’ stands for the division of the night into ten time periods, from sunset to sunrise. The main hunting period for bats is between sunset and the middle of the night. After that, the activity of the night hunters decreases and comes to an almost complete standstill until sunrise.

With Fleximaus, wind power operators are no longer bound to rigid shutdown times, but can often restart their turbines much earlier due to the measured and evaluated hunting activities, and thus work more economically. Fleximaus also prevents unnecessary shutdown in times of rain, as bats have been shown to stop hunting around the rotor blades as soon as drizzle sets in.

Robust industrial PC defies extreme climatic conditions

An essential technical component of the solution, in addition to the intelligent software as well as rain and temperature sensors, is an industrial PC with integrated soft PLC as the 'heart' of the solution. In the current version of the Fleximaus-solution, the Franconians have installed the KBox A-150-APL from Kontron. "The embedded Box PC convinced us with its compact design, short delivery times, and attractive price/performance ratio," explained Jochen Rößler.

In addition, the industrial suitability and flexibility of the Kontron solution also played an important role. ‘The KBox A-150-APL furthermore convinced us because of its fanless, robust design, which guarantees an extended service life and high system availability’. In addition, the KBox requires little space due to its compact design and can be used even under difficult climatic conditions. A further criterion for the award of the contract to the Kontron product is the wide range of interfaces and expansion options that Kontron guarantees Fleximaus managers. 

The KBox A-150-APL is equipped with an Intel Pentium Quad Core N4200 processor and, despite its low power dissipation, offers exactly the high performance that a solution like Fleximaus requires. "Our decision to install the KBox in the future was also made because Kontron meets high security criteria, as required in the IoT environment," said Rößler.

Effective solution at attractive costs

Fleximaus has not regretted the decision to implement the future generation of Fleximaus with the KBox from Kontron.

"In terms of performance and application possibilities, the KBox is much more effective than other solutions we have tested," concluded Rößler. "In addition, the industrial computer produces considerably less waste heat, which makes it predestined for our field of application, as no additional cooling elements are required, which would drive up costs".

This also benefits the customers, because with the KBox and the special software, Fleximaus provides wind farm operators with a smart solution that combines species protection and economic efficiency.