Optimierung von Wasserkraft und Ökologie bei Erneuerung oder Revitalisierung bestehender Anlagen – „win-win“-Ansatz

摘要

In Austria, using hydropower has a centuries-long tradition. Whereas we first placed mills along our rivers to put water’s power to use, today we have over 5,200 water power stations of various types, from the smallest facilities to pumped-storage hydroelectric plants in the Alps. Today, water power accounts for roughly 60 % of our domestic power production, though the various types of power stations used have diverse ecological effects. This article presents a “win-win” approach to improving both hydropower production and ecological outcomes on the basis of the Kamp River in Lower Austria. The Kamp is not only home to a pumped-storage hydroelectric plant and the major plants Ottenstein, Dobra-Krumberg and Thurnberg-Wegscheid, but also to 14 smaller plants with turbines that are between 25 and 75 years old, many of them with energy conversion efficiency ratios of well under 0.7. Using the case study of a small water power plant, the chances of achieving a win-win situation are presented in detail. In this context, replacing the turbines is a major aspect of improving these plants. Extensive analyses have demonstrated that balanced planning approaches can yield both higher efficiency and better conditions for aquatic ecology, thanks to increased residual flows. Further, energy calculations and numerical habitat simulations have confirmed that a win-win situation is feasible for the small power plant studied, especially if Kaplan turbines are used. For example, they show that, despite the increased residual flow of up to 800 l/s, a considerable performance increase over the status quo is possible (maximum performance increase of 17 % without considering residual flow). If the residual flow was only 400 l/s, which tests indicate would mean an improvement in the habitat conditions for all ages of the dominant fish species (the brown trout) of > 50 %, a performance increase of 8 % would be the result. Thanks to the generally applicable methodology used, the win-win approach presented here can broadly be used in the optimization, efficiency improvement and revitalization of current hydropower plants, producing both more electricity and higher residual flow levels to improve local ecological conditions. In order to make this win-win situation a reality, innovative and integrative financial models for e.g. new turbines related to the fields of green energy production and environmental protection will be essential.