The world’s largest in-stadium solar power plant has been built on the roof of the Tissot Arena in Biel. Its capacity: 2.1 MW driven by 62 ABB TRIO inverters.
Interestingly, this kind of milestone project was discussed for possible development in Zurich but Biel was able to bring it to fruition. The Tissot-Arena is a multifunctional sports arena for soccer and hockey. In addition, the facility contains a curling arena, a covered public space, restaurants, stores, and a multiplex cinema.
Biel as a self-declared “energy city” is committed to a sustainable energy policy. The Energie Service Biel/Bienne (ESB), is the leading energy service provider in the Biel region.The ESB has been independent since 2013, but is still owned by the city of Biel as a community venture. It strives to promote the use of renewable energy and to contribute to the change in energy policy and generation.
The power plant on top of the Tissot-Arena not only significantly increases the power produced from renewable energies for ESB, but the installation is also the largest solar power plant integrated into a sport stadium globally – hence, it is a showcase project for the use of solar energy throughout Switzerland. The average annual production is expected to be roughly two gigawatt hours: the installed capacity is 2,106 kilowatt peak (kWp).
The enormous sports complex features an extended roof which has approximately 16,500 square meters of space available for the solar modules – a total size of two soccer fields. “It was quickly clear to us that we wanted to use this space on top of the stadium for a solar power plant since it had very little shading,” said Davide Crotta, project lead renewable energies at Energie Service Biel/Bienne (ESB).
The roof-top solar plant was connected to the grid in June 2015. The expected annual energy production will equal the consumption of approximately 500 average Swiss households. “There are now two staircases to the roof-top, so we can show the solar power plant to interested parties up close”, said Cotta. As impressive as the Tissot-Arena is from the outside – it shows its sustainable “sunny side” best when viewed from above.
The project on the Biel stadium was developed by Helion Solar. “This has been one of the biggest solar power plants we have ever built”, said Remo Nyffenegger, head of marketing at Helion Solar. Helion Solar offered a decentralized solution with 62 ABB TRIO 27.6 kW inverters. “We have been using ABB inverters for some time now and our experience has always been very positive”, said Nyffenegger. In addition to their proven reliability, high efficiency up to 98.2 percent and broad input voltage range, the TRIO inverters were selected because of their two independent MPPT (Maximum Power Point Tracker) per inverter which guarantee optimal energy output in the case of multiple strings with different orientations and angles.
Pricing was only one of several criteria in the tender. Sustainability, productivity, and references were also important as well as system design. “We also looked at the option of installing a central inverter on the roof”, said Crotta. “However, the decentralized design using multiple TRIO inverters offers specific benefits. It is more robust with regard to servicing the inverters as it is a substantial effort to repair or replace a central inverter in case of malfunction. In addition, the direct current cabling is much less complex with a decentralized solution”.