Case Study Description

The Markersbach Pumped Storage Power Plant is a hydro-electric power station using pumped-storage technology. It the second-largest hydro power plant in Germany in terms of installed capacity. The plant is also one of the largest hydro power plants of its kind in Europe and supplies 196.000 households with electricity.

The power plant consists of a top reservoir and a bottom basin. The top reservoir is an artificially constructed basin without any natural inflows with a slope incline of 1:2. It is located 850 meters above sea level and can store 6.3 million m3 of water. The bottom basin construction is 563 meters above sea level. During times when a surplus of electrical power is available, water is pumped from the bottom basin up to the upper reservoir. The hydro power generating sets are housed in a 44-metre-high cavern about 120 meters below ground level.

The reservoir owner was planning to raise the height and regenerate the upper and lower reservoirs in 2015-16. This significant project required different technical solutions so four different test areas or field trials were set up to investigate the most effective combination of materials to use in the regenerative works.

The field trials covered an area of 3.600m2 and the results from the testing were monitored over a four year observation period. It is the first time that field trials of this kind have been used and they represented a huge investment for the client to ensure that the most effective solution was used for the major regeneration project.

Field trials 1 and 2 measured 800m2 each and Field Trials 3 and 4 were 1000m2 each. The Field trials have each been built with different layer compositions and different drainage systems connected to the existing drainage in the base. In addition, two different types of dam heightening material and three different finishes at the dam crest as well as different types of wave-breakers were built.