46 million for unimpeded transmission of sun & wind power: APG celebrates installation of 100th transformer

Transformer number 100 is connected to the grid - another 65 planned

"In addition to expanding renewable energy sources, a comprehensive expansion, modernization, and digitalization of the existing grid infrastructure is necessary to achieve the energy transition. By the same token, the existing infrastructure must be used optimally so that even more sustainable electricity can be transported to where it is needed throughout Austria and Europe with as few constraints as possible. Sufficient line capacities are often unavailable,” emphasizes APG’s spokesperson Christoph Schuh and adds: "The start of operation of the one-hundredth transformer in Austria is an important milestone for a successful energy transition that does not jeopardize the security of supply. The APG grid development plan envisages 65 additional transformers by 2034 as part of the company’s 9 billion euro investment scheme. This will be a major challenge. But the goal is clear: the unimpeded transmission of solar and wind power by 2040."

Special transformer improves transmission of renewables

Fully equipped with cooling and ventilation systems and two tanks filled to the brim with 225,000 liters of insulating oil, the new transformer weighs 900 tons, has a capacity of 600 megavolt amperes (MVA), and can break new ground in the transmission of electricity: The one-hundredth giant transformer in APG's electricity grid is special in many respects.

APG invested 16 million euros in the new phase-shifting transformer at the Ybbsfeld site, whose task is not to transform electricity from one voltage level to another like its "conventional" counterparts do. "We use special transformers at some of our sites in the APG grid: phase-shifting transformers can redirect current flows from one line to another to relieve the load on them. This makes it much easier to integrate renewable energy," says APG’s Bernhard Joksch, who managed the installation of the transformer.

Gigantic power distributor for € 30 million

To integrate the new transformer in the Ybbsfeld substation, 30 million euros had to be invested to expand the site, which included the installation of a kind of gigantic power distributor. The project manager explains how it works: "Over the past two years, we have built two new 220 kV switchgear panels, a third busbar, and a second connector on an area of around 11,000 square meters. Viewed as a single unit, this system could be compared to the distribution box in every household, which ensures that the electricity reaches the washing machine, TV, or oven as required. In our case, with the help of these components and the new transformer, the electricity is diverted from the Ybbsfeld substation to the west to the Ernsthofen substation, or the east, to the Bisamberg substation, depending on the current grid constellation."

Seven remote-controlled phase-shifting transformers in use throughout Austria

The transformer is controlled from Vienna’s 10^th district, as is the entire operational management of the APG transmission grid: At the click of a mouse, a tap changer can be activated at APG’s control center to redirect the flow of electricity to avoid impending grid bottlenecks - both regionally and internationally. Sounds simple. In reality, however, this process is based on highly complex considerations. Seven of the 100 transformers in the APG grid have already been built for this purpose. In addition to Ybbsfeld, these are located at the equally neuralgic sites of Ernsthofen, Lienz, Nauders (two of them), Tauern, and Ternitz. The phase-shifting transformers also help to reduce the cost-intensive need for redispatch measures, which involve gas-fired power plants increasing or reducing their production at short notice to stabilize the grid. In 2024 alone, this type of intervention in the schedules of power plants was necessary on 145 days up to the end of September, resulting in costs of €75.6 million. 

APG calls for better general conditions for a secure, affordable energy transition

Improved general rules and regulations are needed to ensure that all grid infrastructure projects for a secure and affordable energy transition can be implemented on time by 2034 - this includes in particular:

• A massive acceleration of approval procedures
• Coordinated overall system planning and implementation (storage, grid, production, reserves, use of state-of-the-art digital platform technologies) 
• Implementation of a nationwide coordinator for the energy transition in Austria
• Future-proof regulatory system
• Providing the authorities with sufficient resources 
• Protection of planned and existing transmission line routes 

The legislative proposals for the recodification of the electricity law through the Electricity Industry Act (ElWG) and the procedural acceleration instruments through the Renewable Energy Expansion Acceleration Act (EABG), which have already been drafted, are essential building blocks for the realization of these goals. The prompt adoption of these laws is a prerequisite for the timely implementation of all projects relating to the energy transition.

Only if these framework conditions for investments in the grids can be fundamentally improved can the transformation to a secure supply and thus the integration of renewables take place in an affordable manner.