Innertkirchen 1 Power Plant Turbine and Generator Replacement Project

The Innertkirchen 1 power plant, built between 1939 and 1943, utilizes the approximately 670-meter drop between Handeck and Innertkirchen to generate electricity and features five vertical, twin-nozzle Pelton turbines with a total capacity of 240 MW. After more than 80 years of operation, the turbine-generator sets have reached the end of their service life and will be completely replaced.

The project includes the replacement of turbines, generators, valves, distribution lines, and cooling water systems, as well as the dismantling and disposal of the existing equipment.

This tender covers the following four areas: Turbine The tender includes the design (engineering), manufacturing, delivery, installation, testing, and commissioning of five vertical, six-nozzle Pelton turbines, including all auxiliary systems.

Main components: • Turbine with impeller, ring main, regulating nozzles, and casing • Turbine shaft with guide bearing • Hydraulic power units and instrumentation • Digital turbine controller • Vibration and speed monitoring The nominal flow rate per machine is 8.6 m³/s, and the nominal power output is 50 MW.

Generator This lot includes the design (engineering), manufacturing, delivery, assembly, testing, and commissioning of five synchronous generators (each 55 MVA, 13.5 kV, cos phi 0.9, 600 RPM) including excitation system, cooling systems, and instrumentation.

Main components: · Synchronous generator, vertical design · Brushless excitation system · Air-to-water cooler (closed system) · Bearing and braking system · Generator instrumentation and standstill heater The generator is to be designed according to the Transmission Code 2019 (Swissgrid) for frequency and voltage regulation, primary control, and phase-shift operation.

Cooling water system The scope of work includes the renewal of the entire cooling water system for the generator, bearings, turbine governor, and transformer.

Main components: · Closed cooling circuits with heat exchangers · Piping systems and valves · Pumps, control valves, and sensors · Monitoring equipment and connection to the control system The goal is a fully automatic, redundant cooling system with controlled cooling water temperature.

Dismantling of existing turbine assemblies This lot includes the complete dismantling and disposal of the existing five turbine assemblies, including all auxiliary equipment, piping, and foundations. The work will be carried out in stages, partly in parallel with the installation of the new machine groups, to minimize operational disruptions.

All materials will be separated, documented, and disposed of or recycled professionally in accordance with applicable regulations.