Renewable energies

Designation of areas suitable for wind energy in regional planning 

In Brandenburg, the regional planning communities are responsible for controlling the development of wind energy. They define areas for wind energy use in the form of suitability areas in sectoral sub-regional plans or integrated regional plans. There are five of these planning communities in Brandenburg, with the Lausitz-Spreewald regional planning community in southern Brandenburg responsible for drawing up the regional plans.

Regulations, investigations and measures

Wind energy is one of the most visible technologies in the landscape. Understandably, residents therefore wonder whether wind turbines near residential areas will affect their quality of life.

Residents have a special role to play when investigating the environmental impact of a wind farm. The relevant immissions are light sources, shadow flicker and noise (sound). External experts will examine whether the existing legal regulations and limit values for the Forst-Briesnig II wind farm are complied with. For this purpose, the licensing authority - the Brandenburg State Office for the Environment - defines so-called "immission points", which are the basis for representative measurements and forecasts. If an exceedance of applicable guideline or limit values cannot be ruled out, appropriate technical mitigation measures are planned, which later also become part of the permit. The operation of the wind turbines in compliance with the permit is checked by the State Office for the Environment.

Noise and sound:

• Regulation: Technical Instructions on Noise Protection (TA Lärm) and WKA Noise Immission Decree
• Procedure: Identification of significant immission locations with the highest protection requirement; in Briesnig and Bohrau, immission guide values of between 40 and 45 dB at night and 55 to 60 dB during the day apply, depending on the area category; the assessment of the impact is based on the total load (incident and additional load).
• Possible mitigation measures: aerodynamically optimised and adjustable rotor blades; operation of noise-determining turbines in noise-reduced mode; integrated computer system throttles the turbine when the limit value is reached.

Reduced speeds, non-reflective paints and sensor-supported shutdown as soon as guideline or limit values for immissions are reached - to ensure that the neighbourhood of wind energy and residential development succeeds, state-of-the-art turbines are used.

There are also defined immission protection regulations for the shadow cast by the rotor blades of wind turbines. According to these, a wind turbine must be temporarily shut down if its shadow falls on a residential building for more than 30 minutes a day and 30 hours a year. If it is foreseeable that the sum value for shadow flicker will be exceeded, the turbines are equipped with shadow flicker modules for automatic shutdown. The annual value for the actual shadow duration is then limited to a further eight hours.

Shadow flicker

• Regulation: WTG shadow flicker guideline 
• Procedure: Identification of relevant immission points with the highest protection requirement; irrespective of the area classification, a maximum of 30 minutes of shadow flicker per day and a maximum of 30 hours per year or, if a shadow flicker module is installed, only 8 hours per year apply; the assessment of the impact is based on the total load (incident and additional load). 
• Possible mitigation measures: Installation of a shadow casting module, which works with light sensors, takes into account the actual weather conditions and switches off the plant when the sum value for shadow casting is reached.

Lighting

• Regulation: Needs-based night lighting in accordance with the General Administrative Regulation (AVV) for the marking of aviation obstacles and the Renewable Energy Sources Act (EEG).
• Measure: Lighting is only activated if movements in the airspace actually require it; no continuous "flashing".

For the approval and construction of wind turbines, the protection of bats and the so-called "avifauna" as a totality of all bird species occurring in a region is of great importance. This is ensured by nature conservation studies as part of the approval procedure for a wind farm. In preparation for the approval procedure for the Forst-Briesnig II wind farm, extensive mapping was carried out in accordance with the statutory provisions. The Federal Nature Conservation Act and the decree of the Ministry for the Environment, Health and Consumer Protection of the State of Brandenburg on the consideration of nature conservation issues in the designation of suitable wind areas and in the approval of wind energy plants are decisive here. 

In addition to the breeding birds on the agricultural land on which the wind turbines are to be erected, the eyrie sites and main flight paths of disturbance-sensitive large bird species in the vicinity of the turbines also play a major role. Furthermore, roosting waters and feeding areas of migratory and resting birds in the vicinity are also included in the considerations. The bats occurring in the planning area, their habitat potential and their activity areas are also recorded. 

The main focus of the nature conservation studies is to be able to derive statements on possible threats to birds and bats from the wind farm. If significant impacts appear likely, appropriate avoidance and mitigation measures are integrated into the permit application. These may include temporarily shutting down the wind turbines during periods when, for example, bats are particularly active.

Higher is better

Practice and the growing body of experience in the wind energy industry show that tall turbines reduce the overall risk of collisions. Turbines like the one planned in Forst-Briesnig II project further out of the activity zones of avifauna and bats. Thus, their rotor sweep is above the regular flight height of many animals.