Bilfinger, an industrial services provider, is supporting energy company Ignitis Gamyba to expand the Kruonis pumped storage hydroelectric plant in Lithuania. The project, in conjunction with technology group Voith, aims to fortify Lithuania's independent energy supply and aligns with the region's commitment to integrate into the European power grid by the end of 2025.

As part of this strategic initiative, Bilfinger will supply large pressure piping for the new pump-turbine unit at the Kruonis plant. This marks Bilfinger's inaugural hydropower project in the Baltic States. The expansion comes at a crucial time as the Baltic States endeavor to reduce their reliance on energy imports and systematically expand renewable energy sources.

Situated around 35 km east of Kaunas and 80 km west of Vilnius, Kruonis was initially designed to accommodate eight pump turbines. However, upon its completion in 1992, only four machines, each boasting an output of 225MW, were commissioned. Voith is set to provide a new fifth pump-turbine unit, and Bilfinger is tasked with constructing a new exposed pressure pipeline. This pipeline will connect the upper basin of the power plant with the lower basin and the pump-turbine.

A team from Bilfinger Industrial Services Austria is overseeing the complete value chain for the pressure pipeline, stretching approximately 900 meters with a diameter of 5,250mm. Their responsibilities encompass engineering, fabrication, transportation, installation, corrosion protection, and commissioning. Adapting to the existing plant components and the surrounding conditions presents a distinct challenge. Given the absence of detailed plans for the old plant, a precise condition assessment becomes essential. This assessment aims to guarantee the stability of the pipeline under challenging conditions, including extreme temperature fluctuations of up to 80 degrees Celsius, substantial water loads, and the intense dynamic pressure from the connected turbine.

To ensure the highest quality and durability of the pipeline, state-of-the-art thermomechanically rolled steels are used. The huge components are prefabricated to the nearest millimeter and precisely joined on site using metal active gas (MAG) welding. This advanced welding process has the advantage of preventing hydrogen from penetrating the weld and allows for automation, which increases the quality and speed of the process. Bilfinger also uses automated ultrasonic testing to ensure the highest quality standards.

The new plant is expected to be operational by the end of 2026.