399.58 kWp
532,4 kWh/p.a.
270 tonnes

Enerray has created two rooftop photovoltaic systems on Auchan supermarkets in Cuneo and Palermo, which began operating in May 2014 with respective power capacities of 199.66 kWp and 199.92 kWp. 

The project was commissioned and supervised by Helexia, an energy production and energy efficiency company.

Founded in 2010 by Nicolas Mayaud and Benjamin Simonis, Helexia, part of the French Creadev fund, provides complete energy services to its energy intensive partners, through ESCO energy efficiency actions, photovoltaic installations and cogeneration plants. Operating in Italy, France and Belgium, it works flexibly and effectively in Europe by providing energy solutions and serving as a financial partner and electricity producer, dedicated to transforming energy intensive buildings into Positive Energy Buildings.

These two projects were completed thanks to the trust and synergy that was immediately developed between Enerray and Helexia, Auchan’s partner for energy issues.


The system consists of 1567 photovoltaic modules over a surface of around 14,000 square metres. The two systems combined produce 532,468 kWh per year for own consumption. The investment will allow the two supermarkets to reduce CO2 emissions by over 270 tonnes per year, as well as reducing electricity costs. 

The guidelines used to design both photovoltaic systems aimed to find optimal solutions that met the Customer’s requirements, as well as the relevant technical and regulatory provisions.

The selection of photovoltaic modules was carried out with a focus on the best conversion efficiency, in consideration of the limited surface area available. Two other important criteria were price and reliability, also understood in terms of performance stability during the system’s useful life, which can be estimated at over 25 years. The inverter group has characteristics that were identified on the basis of technical data for the photovoltaic modules, based on their ability to be paired with them.


Project data for the photovoltaic system created on the Auchan Palermo roof:

  • Placement of modules both horizontally on flat surfaces and on small circular domes, in both cases along the E-O axis (azimuth angle Az=36°) on the roof. Modules arranged in rows and aligned along their greater axis;
  • Assembly on support structures consisting of purlins made of aluminium profiles aligned in parallel sets of two for each module line, partially attached using aluminium brackets on fibre-cement corrugated sheets, serving as the covering of the roof with small curvilinear domes and partially using a slanted structure placed on the flat roof using prefabricated weights in concrete, in both cases installed without replacement of materials.

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