The promotion of renewable energies and the protection of animals and the environment are both an aspiration and a motivation for us.René Buob, Head of Grid and Power Plant Management at ewl energie wasser luzern
Inspection and maintenance
On their daily rounds, ewl employees inspect the facility, carry out visual checks, check oil pressure, lubricate bearings and perform general cleaning work.
Overhaul work on the turbines is carried out according to the manufacturer’s specifications. The turbines have to be overhauled after 100,000 operating hours, which is roughly equivalent to 11.5 years of continuous operation. Electronic and mechanical equipment is gradually updated as part of a multi-year overhaul plan in order to ensure the continued safety and reliability of the plant.
It’s a real back-breaking job
Aquatic plants have proliferated in recent years. This can be traced back to more hours of sunshine and the consequent warming up of the water, especially around the bay of Lucerne. In late summer, thick carpets of seagrass measuring several metres in diameter are washed up from Lake Lucerne and clog up the upstream trash racks. When these are no longer working at the required throughput, the machine groups switch off automatically. A horticultural company removes several hundred kilos of seagrass every single day in autumn.
An odd collection of floating debris
The Mühlenplatz small hydroelectric power plant is something of a passion for Ludwig Hafner, inspection and maintenance specialist at ewl. He and his colleagues are dedicated to taking good care of the facility day in, day out. Ensuring its reliable and efficient operation is important to him.
Naturally this means that every now and again he has to clear floating debris and rubbish as well as dead fish and ducks from the trash racks. Some pretty strange objects can get caught in the trash racks, especially during Fasnacht (carnival): “Once, we had to remove a portable toilet. We’ve even fished tables and benches and bales of hay out of the water.” With a smile on his face and an oil can in his hand, he disappears back into the fire-red machine room.
Conditions are better in winter
In summer, when the needle weir is open, the gradient is rather shallow (around 60 centimetres). In winter, when the needle weir dams the Reuss more, the gradient is steeper (up to two metres) so that more power is produced despite there being less water overall. More than half of the annual production of the Mühlenplatz power plant is therefore generated in winter.
Once the height differential is less than 60 to 80 centimetres, the plant shuts down. Following consultation with the municipal carpentry and joinery department, operation can be switched to sail mode. The plant stops producing electricity.
The fish ladder ensures fish passage
“A hydroelectric power plant must comply with numerous legal requirements. For example, we are obliged to ensure fish passage,” says René Buob, Head of Grid and Power Plant Management at ewl.
The fish pass ensures ecological connectivity between the Reuss and Lake Lucerne. There are species of fish that need both flowing and standing water environments during their life cycle. Weirs and turbines interrupt the migration of these fish between the Reuss and the lake. The fish pass enables the fish to get past this technical obstacle. A reinforced “fish window” was installed in the power plant through which the migrating fish can be observed in the fish pass.
Lake trout leave Lake Lucerne in the autumn to breed in the Reuss during the months of November and December. They deposit their spawn in gravel beds and return to the lake after the eggs are laid. The young lake trout remain in the Reuss for one to two years before moving upstream to the lake. Three years later they return to the Reuss as mature adults, ready to reproduce. And so the circle of life closes.
Do fish climb ladders?
The city’s Energie-Tatorte-Trails (Lucerne energy trail) starts at the Mühlenplatz small hydroelectric power plant. Can you solve all the clues?
A walkway for beavers
There are around 3,500 beavers in Switzerland, some 75 of which are at home in the canton of Lucerne. Here the beaver territories are predominantly along the Reuss and its tributaries. The creatures often swim upstream in their search for a suitable habitat. The Mühlenplatz small hydroelectric power plant presents an impassable obstacle for them on their migration journey. It forces the rodents to take a longer, perilous route over land.
In response to this problem, Pro Natura and the Canton of Lucerne’s Department of Agriculture and Forestry set up the “Beaver Ramp” project. A wooden up-and-down ramp positioned in the middle of the small hydroelectric power plant enables these protected wild animals to migrate both upstream and downstream safely. A camera trap with motion sensor has been installed to document the beavers’ movements.