The renovation of the Mühleberg substation included replacing outdoor switching substations with an indoor switching substation. This made it possible to renaturalise an area the size of four football fields, which is to say, convert it back to a habitat for plants and animals.
The installations at the Mühleberg substation had been in operation for up to 60 years and had reached the end of their service life. The former owner, BKW, replaced the old outdoor switching substations with a modern, gas-insulated switching substation. This change in technology significantly reduced the required area by around 29,000 m2 of industrial space, which was converted to natural space and recreational areas. Swissgrid took over the infrastructure project shortly before completion and is building an additional 800 MVA phase-shifting transformer, which is to be completed by the end of 2020. Combining technology and nature in such large construction projects and maintaining a balance between economic and ecological aspects is an exciting challenge. In consultation with all the experts, we managed to find the optimal solution.
Landscapes like these are very rare nowadays. It's great to see a company think sustainably and invest in this nature park. For me as a landscaping business owner, being able to participate in this project was also a great learning opportunity. Flowing bodies of water were exposed, existing industrial structures were integrated, and the bank of the Aare River was modified. It’s simply not possible to plan everything down to the last detail; constant adaptations were required, which we discussed together with the natural environment planner. Given the large size of the area, a great deal had to be organised differently. For example, we had to deal with lorries full of soil instead of wheelbarrows. Another aspect is the length of the project. The renaturation started in 2013 and will be worked on in stages until its completion in 2020. Being able to supervise the development of the landscape that we designed over a longer period of time is a lot of fun.
Maintaining technical installations and their environment is part of our daily business, but this renaturation is new ground for me in many respects. Continuously investing in the quality of natural areas requires a great deal of expertise. All of a sudden I had to start dealing with topics such as battling neophytes, which are non-native plants, and the spawning seasons of frogs. Gravel pits, stacks of old wood and mounds of earth – the landscape looks fairly nondescript at first glance. I only really understood the idea of the nature park and its elements after talking with the specialists. The outlay that this will require remains to be seen. Ideally, the long-term maintenance costs will be lower than if an intensively managed meadow had been created.
An environmental impact report with a layout plan for the renaturation was submitted as part of the planning approval procedure for modernising the substation. This project shows how the environment around substations can be handled in close touch with nature and how industry and nature can be combined. The responsible companies have given something back to nature and the citizens. But a wide range of interests had to be taken into consideration during the construction of the new substation: rapid construction progress, the concerns of farmers affected by the renaturation, 200 different environmental requirements and, of course, the ideas for redesigning the environment. The result is a «green techno-park», which has, in part, used existing structures to design new natural areas. What I like is that the importance of the landscape in this region of the Aare was recognised.
GIS substations are completely gas-tight, encapsulated substations. They are low-maintenance and better protected against external influences. These substations take over the actual electricity distribution; this is where the lines and transformers are connected to each other. Substations make it possible to change the grid topology (structure of the electricity grid), and both lines and transformers can be disconnected and earthed for maintenance work.
