Extension of pumped storage plant Waldeck 2 in northern Hesse/Germany

Abstract

The favorable conditions which are offered by the location Waldeck / Lake Eder in Northern Hesse for the realization of pumped storage power plants were already identified more than 80 years ago. In 1932 the pumped storage plant Waldeck 1 was commissioned with 4 units and a total capacity of 140 MW. In the years 1974/75 the Waldeck 2 scheme with two additional units in a cavern powerhouse and a total capacity of 480 MW was added. When planning the Waldeck 2 scheme in the 1960s, a future extension of the plant had already been considered and the basins were designed accordingly. In early 2009 the design work was resumed for the extension of Waldeck 2 called Waldeck 2+. The review of the old concepts revealed that significant parts of the Waldeck 2 scheme as upper basin, lower basin, access tunnel to the cavern, tunnel for energy evacuation, and the outdoor switchyard including the 380 kV grid connection can be used for the new plant. For Waldeck 2+ a variable speed pump-turbine with a capacity of 300 MW is foreseen to be installed in a new underground powerhouse south of the existing cavern. The new waterway will connect at the upper reservoir to the already existing outlet / intake structure via an also already existing segment of the penstock passing under the dam of the reservoir. It will then follow an alignment through the new cavern and a new tailrace tunnel to a newly constructed outlet/intake at the lower basin.