The leading Swiss solar energy company TRITEC realized, for company Migros, the largest solar power plant in Switzerland with a power rating of 5.21 MWp. After less than five months of construction, the plant was commissioned in mid-August.
The front rows of solar modules on the roof edges are already visible from the autobahn A1. What you cannot see: On the huge roof areas of the distribution centre of Migros-Verteilbetrieb Neuendorf AG, there are over 20,000 additional solar modules which were installed in stages by qualified solar fitters from TRITEC. In coming decades, this solar module array will convert sunshine at the southern foot of the Jura mountains into sustainable energy.
The solar power plant with a total output of 5.21 MWp (megawatt peak) comprises four photovoltaic systems which are distributed over six buildings. Altogether nine flat roofs are covered with 20,039 mono-crystalline 260-watt solar modules. The total module surface amounts to more than 32,000 mÂ². Inverters to be used are over 60 string inverters and 12 central inverters of SolarMax from the Swiss manufacturer Sputnik Engineering AG.
Specially developed sub-structure
The choice of sub-structure required special know-how and specific calculations to meet the characteristics of statics and stress analysis of the flat roofs. To this end and for a neutral-weight roof load, the green roof (substrate) had to be suctioned off and replaced by gravel. Moreover, for module supports, the new designed, particularly low-ballast and aerodynamic mounting system TRI-FLAT was used. With an optimized 10-degree inclination, the mounting system is oriented slightly southeast.
For the first time, compact transformer stations installed directly on roofs
«With the two partial systems of 1.7 MWp and 2.0 MWp, we are feeding, for the first time, solar power directly on the roof into the medium voltage grid», says Roland Hofmann, Managing Director of TRITEC AG, Switzerland, «we thus prevent possible losses and bring electrical energy fast and optimally from low voltage of 320 volts to medium voltage of 16,000 volts.»
By crane, the compact stations weighing several tons were hoisted in two steps onto the up to 20-meter high roofs of Migros-Verteilbetrieb Neuendorf AG â€“ first the housing and then the transformer. The compact transformer stations with a rated output of 1.6 MW and 2.0 MW stand on specially poured concrete foundations.
Energy for over 1,300 households
The generated energy will be fed into the power grid of Elektra Neuendorf. Annually, the photovoltaic power plant will produce 4,836,000 kWh in clean solar power. This is equivalent to the average consumption of about 1,300 households. Thanks to the non-polluting energy generation of this solar power plant, a total of 2,853 tons of CO2 emissions can thus be avoided.
For the turn-key project, TRITEC was responsible, as the general contractor, for the project engineering from design calculations via construction planning all the way to commissioning.