University Designs Small-Scale Low-Impact Hydro Plant

(Technische Universitaet Muenchen)

Researchers at Technische Universitaet Muenchen (TUM) in Germany have developed a small-scale hydroelectric power plant that solves some of the problems often encountered when building these facilities:  high cost, environmental degradation, and impact on fish. The developers believe this design can make hydroelectric power more feasible in more places.

Hydroelectric power, while consuming no fossil fuels, relies on strong constant currents of water to turn the generator’s turbines. In the past, that has meant large dams that provide a powerful cascade of water. Each dam and plant is custom-designed, which adds a lot of time and expense. And hydro power plants need the capability to let fish bypass the dam, which in some cases is negated by the strong whirlpool current that draws fish into the turbines.

TUM engineering professor Peter Rutschmann and research engineer Albert Sepp have developed a small-scale hydroelectric power plant model that meets these issues. The water flows into a box-shaped unit (pictured right) that drives the turbine and then guided back into the river underneath the dam. Rutschmann and Sepp say this approach is practical since several manufacturers have developed generators that are already capable of operating underwater, thus removing the need for a separate power house on the river’s bank. Only a small transformer station is needed there.

The model dam also has a gate in the dam above the power plant’s shaft to reduce the whirlpooling that can damage the generator’s turbines. This gate as well serves as a bypass for fish that protects them from contact with the turbines.

Rutschmann and Sepp say that the smaller scale of the plant makes it possible to design pre-fabricated components that builders can assemble on site, rather than requiring a custom design and construction from scratch. For larger rivers, multiple units could be installed.