Open Access

As Germany aims to increase its utilization of wind power, the potential threat to bird populations due to this expansion is a controversial issue. This paper aims to collect data on the magnitude of bird strikes on wind turbines, review existing protective measures and explore innovative solutions. After a thorough examination of the literature, it was concluded that although the impact on bird populations is significant, it may be overemphasized in popular debates. This statement is not final as further research is necessary to assess the impact of bird strikes and explore new solutions. Comprehensive studies on this specific topic in Germany are limited, which makes a thorough evaluation challenging. While there are measures in place to protect species that may be negatively impacted, it is possible that these measures will not be adequate for all of them. While several innovative methods are under examination, progress in testing and implementation is slow. Lastly, an information problem was identified. Since the topic is highly politicized and polarizing, it is crucial to provide the public with accessible and reliable information on the discussed themes. This is currently not the case due to a lack of data and missing information campaigns.

This paper outlines the three main areas relevant to dismantling: the rotor blades, hub and nacelle, the tower and the foundation. The paper discusses the dismantling procedures, including the removal of the top structure, the tower and the foundation, and evaluates various methods of dismantling the tower, such as modular dismantling, collapse blasting, folding blasting, wrecking ball demolition and hydraulic ram demolition. The assessment of these methods in practice and the potential challenges and considerations for future dismantling, particularly as wind turbine heights increase, are also addressed.

The pursuit of Offshore Wind Energy (OWE), integral to the German government’s ambitious renewable energy goals raises concerns about the environmental impact of noise emissions on marine life. This paper delves into the theoretical background of Offshore Wind Turbine (OWT) noise, exploring its various phases from the survey to decommission. It examines the types and causes of noise emissions, their effects on marine wildlife and potential mitigation measures. Highlighting the regulatory framework in Germany, the paper emphasises the need for nuanced approaches to balance renewable energy objectives with marine ecosystem preservation.

The construction and operation of hydropower plants for energy generation is a major issue in sustainable energy production. Nevertheless, hydropower plants have a negative impact on fish populations. It is crucial to understand the causes and consequences of fish mortality in hydropower plants in order to find sustainable solutions that reconcile the need for energy with the conservation of aquatic ecosystems. This article examines the fish protection measures that can be implemented to reduce fish mortality and maintain ecological balance. Based on the main literature reviewed, this article mainly refers to Germany in terms of studies carried out and hydropower plants.

The annual wastewater flow that is treated by public wastewater treatment plants in Germany amounts to approx. 10 ∗ 10^9 m3/a and forms an ”artificial” hydropower potential that can be used for energy generation or recovery. In the context of this paper, energy recovery in the outlet of wastewater treatment plants is examined using the specific example of the water wheel at the Warendorf central wastewater treatment plant. The ”artificial” hydropower potential can be roughly estimated at up to 20 to 105 GWh/a , whereby this is largely dependent on the hydraulic gradient. The strong variance results, among other things, from the findings of the water wheel operation in Warendorf. The decisive aspect here is the differential factor, which describes the deviation between the theoretical and actual energy yield of the water wheel. The factor includes maintenance work, downtimes and insufficient inflows, which are associated with a loss of output. In the case study, the annual energy recovery amounts to approx. 2 % of the annual electricity consumption of the wastewater treatment plant and can be estimated to 23,500 kWh (2022). In the context of the economic analysis, it can be seen that despite the ”low” yield, economic operation is possible if the system is viewed as a long-term investment - payback period of the example is approx. 14,5 years. The 27-year operation (1996 - 2023) of the water wheel at the Warendorf central wastewater treatment plant confirms this and important findings on successful practical operation can be shown in the context of this paper.