It’s been plugged in for decades

Europe’s oldest grid-connected solar system has been functioning for an incredible 35 years and it’s proof that quality installations have a service lifetime of decades. Installed in 1982 when photovoltaic technology was developed to just a fraction of the degree that it is now, the 10 kW system has been able to contribute clean power to the grid for so long purely due to the quality of the original installation.

Europe’s oldest solar installation has been serving green power for 35 years

Although the TISO‐10 (TIcino SOlare) PV system only has a capacity of 10 kW, the installation, which sits on top of the roof of what today is the SUPSI PVLab at the University of Applied Sciences and Arts of Southern Switzerland, has been doing its job for almost 40 decades. The reliable renewable electricity system is so notable in its steady operation that a research team was compiled to investigate its performance and report on the findings.

One key point noted about this PV system was that solar modules operating in temperate climates can offer service lifetimes of 35 years and beyond if the right materials, quality equipment, and correct installation methods are used. It was also highlighted that the bill of sale at the time of installation was vital to the longevity of this installation.

Although the technology used in 1982 was considered ground-breaking, more recent advancements are light-years ahead, like a plan to marry solar and nuclear energy in one plant.

Research over 35 years shows why this solar power system had such success

The performance of the University of Applied Sciences and Arts of Southern Switzerland’s solar electricity array was monitored for 35 years from 1982 when it was commissioned to 2017, when two scientists were tasked by the Swiss Federal Office for Energy (SFOE) with analyzing the massive volume of data. It took the scientists, Alessandro Virtuani, senior researcher at the École Polytechnique Fédérale de Lausanne (EPFL), and Mauro Caccivo, head of the SUPSI PVLab itself, and their team two years to collate the figures and their findings.

Project installation details

At the time that the Swiss PV installation was built, the cost was CHF 284,000 (Swiss francs), which was around $475,000 at the time and $309,000 today. A total of 288 modules were incorporated and it cost around CHF 21 ($37 at the time and $22,90 today) per watt. Arco Solar provided the glass backsheet panels that had a power output of 37 W each. Caccivio explained the technology of the time:

“When the modules were bought in 1980, Arco Solar was one of the world’s largest manufacturers and had around 1 MW of annual production capacity.”

The system’s durability is marked by minimal maintenance and no replacement of panels

Replacements of inverters meant that the electrical configuration of the system had to be changed several times over the decades. However, all the modules are the original units and have never been refurbished or revamped, with the exception of a few bypass diodes and junction boxes. The panels have been exposed to the elements continuously, and Virtuani and Caccivio highlighted the significant robustness of the materials and setup:

“These modules have an impressive mechanical robustness. But they can tell us a lot about humidity penetration and yellowing. Each panel was encapsulated with a backsheet made of steel foil functioning as a barrier to water ingress, which is sandwiched by Tedlar layers on both sides.”

The Swiss PV installation’s long and productive life is a model for current installations to follow, although it’s likely that many of the materials used would be deemed no longer sustainable from an environmental point of view, among other sourcing and cost complications. On the other modern end of the spectrum is an innovative, super-scale solar panel project that will see 52 billion panels installed across the United States.