Solar instead of nuclear power – 100 % sustainable energy. More than 35 years after the national referendum, the NPP Zwentendorf finally produces electricity for Austria’s households. In contrast to earlier times, there have not been any protests by nuclear power opponents because the photovoltaic facility produces 100 % sustainable, environmentally friendly electricity.

The photovoltaic power plant Zwentendorf was expanded based on the public participation model “Sonnenkraftwerk Zwentendorf” (Solar Power Plant Zwentendorf) in 2012. In this context, 1,300 solar panels were available to interested residents in Lower Austria – they were sold out just a few days later.

After the expansion, the photovoltaic facility Zwentendorf is comprised of about 2,300 solar panels. Instead of the originally planned 700 MW of capacity, the panels generate around 450 kWp of solar power for households and the regional industry. This site applies numerous technical principles ranging from a rooftop facility and side wall systems to an open-space solar park on the grounds of the power plant. The latter includes fixed supported solar generators and sun-tracking solar systems that produce up to 25 % more electricity than those permanently mounted.

The research conducted in the field of photovoltaics is just as necessary as it is state of the art. EVN operates the first expansion stage in cooperation with the Vienna University of Technology (TU Wien) as the Photovoltaic Research Centre Zwentendorf.
At the site of the nuclear power plant, commercially available photovoltaic modules, solar tracking systems, solar inverters and auxiliary equipment are tested and evaluated for their efficiency, practicality, investment and projected operating costs under real environmental conditions.
One objective is to gather experience as to which panels are optimally suited for house and garage roofs.

An extensive measuring system has been installed to provide detailed global radiation measurements to this research. The system includes sensors to document direct and diffuse solar radiation, a weather station to document wind, rain and temperature, and cameras not only to monitor changes in module surface due to snow, rain and general environmental sediments but also to evaluate the self-cleaning effects.

The first year’s results of different positions and combinations are extremely impressive. The sun tracker produced 1,300 full-load hours, the open-space solar park and the roof around 1,070 h/a, and the side walls SE 780 h/a, SW 630 h/a and NW 354 h/a. These numbers show that in Lower Austria rooftop PV facilities are already able to produce excellent yields even without tracking systems.

NPP as the ideal site

Zwentendorf is an outstanding location for this project: as the plant’s premises are still dedicated as a possible power plant site, there is no need for any additional, complex and expensive permits. The existing infrastructure is another key advantage because Zwentendorf already provides various important facility elements to feed electricity into the power grid. Even though there many opposing opinions, both the cables and the electricity distribution system still in excellent condition. While the power lines were checked annually for their functionality, the entire facility has been carefully conserved for the last three decades. In a nutshell, Zwentendorf is more than ready for its next big step onto the energy stage.