First 175-metric-ton transformer section delivered to APG's Kronstorf substation

On September 5, the 7.6-meter-long, 4-meter-wide, and 4.6-meter-high transformer section set off by rail from the Siemens Energy plant in Weiz to Enns station. There, it was loaded onto a so-called PST self-propelled modular transporter with ten drive axles using a special lifting frame. Following a road closure in the city of Enns from 10 p.m., the 175-metric-ton load was transported remotely, step by step, over a distance of approximately 13 kilometers to the Kronstorf substation. The journey took around three and a half hours and partly followed the Enns River.

“Transporting a 175-metric-ton transformer section through public roads requires meticulous planning down to the smallest detail. Despite modern technology and extensive safety measures, a heavy-haul transport of this scale requires the utmost concentration and close cooperation among everyone involved. We are therefore particularly pleased that the first transformer section has safely reached its destination,” says APG project manager Jürgen Pilgerstorfer.

Once at the substation, the transformer section will be lifted onto its foundation in the coming days. Two more identical sections will be delivered by early November. Together, the three sections will form a new 380/220-kV transformer with a capacity of approximately 550 megavolt-amperes (MVA).

By the time work at the Kronstorf substation is completed in 2029, seven more identical transformer sections will be delivered. These will be assembled into two additional large transformers, with one spare section kept in reserve.

Kronstorf substation as a key hub for Upper Austria’s power supply

Extensive expansion and modernization work has been underway at the Kronstorf substation since 2024. In the future, it will serve the central region—together with the Ernsthofen substation—as an additional feed-in point from APG’s trans-regional 220- and 380-kV extra-high-voltage grid. This will significantly increase the reliability of the region’s power supply and further strengthen Upper Austria as an industrial and economic hub.

The work at the Kronstorf substation is part of the joint “Secure Power Supply for Central Upper Austria” project being carried out by APG, Netz OÖ, and LINZ NETZ. In total the three project partners are investing approximately €800 million in the construction of a new 220-kV supply ring. This will replace the existing 110-kV feed-in system for Central Upper Austria, which is more than 70 years old, and make the region’s power supply fit for the future. The new ring will connect the APG substations in Ernsthofen, Pichling, Hütte Süd, Wegscheid, and Kronstorf. Several substations operated by the project partners will also be integrated into the grid concept.

The project has been under implementation since 2024, with completion scheduled for 2030.

“Substations connect APG’s extra-high-voltage grid with the regional distribution grids. In a sense, they are the on- and off-ramps of the electricity highway. Transformers are the heart of every substation. They convert electrical energy to the required voltage level, ensuring that electricity reaches industry, businesses, and households reliably and at the appropriate voltage,” explains Pilgerstorfer.

About Austrian Power Grid (APG)

As an independent transmission system operator, Austrian Power Grid (APG) is in charge of ensuring the security of the electricity supply in Austria. With our high-performance and digital electricity infrastructure and the use of state-of-the-art technologies, we integrate renewable energies and reduce the dependency on electricity imports, we are the platform for the electricity market, and we provide access to reasonably priced electricity and thus create the basis for Austria as supply-secure and future-oriented industrial and business location and place to live. The APG grid totals a length of about 3,500 km and is operated, maintained, and continuously adapted to the increasing challenges of the electrification of businesses, industry, and society by a team of approximately 1,000 specialists. 67 substations are distributed all over Austria, and the majority are operated remotely from the control center in Vienna. Thanks to our committed employees, Austria had a security of supply of 99.99 percent also in 2025 and thus ranks among the top countries worldwide. Our investments of 680 million euros in 2026 (2025: 595 million euros, 2024: 440 million euros, 2023: 490 million euros) are a motor for the Austrian economy and a crucial factor for achieving Austria’s energy goals. Overall, APG will invest around 9 billion euros in grid expansion and modernization measures by 2035.