Small Hydrpower Plant Guggenloch" - Switzerland

Planning, design and construction supervision of a complete refurbishment of a small hydropower plant (110 kW) at a historical site. Refurbishment of the 100-year old concrete dam.

In Guggenloch, a town in the municipality of Lutisburg in the low part of Tuggensburg, on the small river Gonzen, a small hydropower plant is producing electricity, since January 1996.

This new small hydropower plant, projected and built by the ITECO, has indeed a complete integration in the environment. A 1 cubic m/sec flow on a 15 m high waterfall and an installated power of 110 kW allows to feed 450.000 kWh per year electricity to the public electric network. The old plant, destroyed in 1972 by rock fall, is now substituted by the new SHP. The new small hydropower plant, shortly inaugurated, is fully automatic and represents a successful example of how it is possible to build, in the framework of the programme Diane 10 of Energie 2000, a small plant working very well and with no negative impact on the natural ecosystem and general environment. The Guggenloch project dates back to 1984 ; among some conditions to be satisfied there were that the dam (200 m long and 30 m high) should be preserved and the plant should be built under the ground. Since 1972 and during 24 years, the Guggen river, has been filled with mud and detritus which had to be removed when the works began. So the old dam, older than 100 years and originally built in concrete, is continuing to fullfill its duties with some modifications. In accordance with the clauses of the concesion act, the water level must be always such as to maintain 15.000 cubic m. Taking into account the lack of activity of the plant and the unregular flow of the river, it has been considered necessary to install in the new machine house one Ossberger turbine which allows functionning even with a low water flow. An asynchronous generator produces electricity at network voltage (400/230 V).

The proGuggenloch association, which was the owner of the plant, experienced some difficulties in financing the enormous amount of 1.3 million Francs (CH). Thanks to the support and the knowhow of ADEV, a financing scheme could finally be elaborated with the participation of sponsors, shareholders and loaners, and the help of the federal and regional administrations (5 % each). The profit in selling energy, based on this financing, will allow the plant to cover the yearly costs.