The Köppchenwerk on the Hengsteysee, located between Hagen and Herdecke, is a historically significant pumped storage power plant that was designed and built by Arthur Koepchen between 1927 and 1930. Originally used to cover peak loads in the power grid, it is now a listed building and serves as a technical monument.
The power plant used the difference in height between the Hengsteysee and an upper reservoir to generate energy by lowering water. Outside of peak load times, water was pumped back into the upper reservoir to be used again to generate electricity. This principle was groundbreaking for the time and made the Köppchenwerk one of the first large pumped storage power plants in Germany.
Today the Köppchenwerk is not only a technical monument, but also part of the Industrial Heritage Route and the Herdecke Energy Economics Hiking Trail. Guided tours are available for visitors, giving them an insight into the historic machine hall and how the power plant works. In addition, the site, which is located on a wooded steep slope, offers a beautiful view over the Ruhr valley, which is particularly popular with hikers and those interested in culture.
The future role of the Köppchenwerk in the International Garden Exhibition 2027 suggests that it will continue to be valued as an important cultural and historical point in the region.