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PVsyst Team

André Mermoud

Designer of PVsyst, Physicist, technical and scientific questions

Michel Villoz

Photovoltaic engineer

Bruno Wittmer

Physicist, technical and scientific questions

Michele Oliosi

Physicist, technical questions and development

Sylvain Pepoli

Software development, web services

Nils Lang


Hizir Apaydin

Development, Web services

Stéphane Metz

Software development

Lazare Fesnien

Projects and trainings technical coordinator

Olivier Munos

Community project manager for PVsyst Foundation

Pauline Calame

Accounting, Customer Relation Management

Séverine Mermoud

Communication, Customer Relation Management

Alexandra Jenson

Customer Relation Management


André Mermoud

PVsyst conceptor and Founder

Michel Villoz

PVsyst Founder


A graduate of the University of Geneva (1971), André Mermoud obtained his Ph.D in particle physics in 1977 following research at CERN.

His experiences in solar energy

In 1978, he began with detailed studies of solar thermal systems and innovative energy systems in buildings, at the University of Geneva and several engineering  companies.


Michel Villoz graduated in 1977 from EPFL (Ecole Polytechnique Fédérale de Lausanne) with a diploma in electrical engineering. In 1980, he joined the world of solar energy to coordinate the technology transfer to Switzerland of a solar cells production line from Solarex (USA). He then managed the production of cells and participated to the design of the Pasan sun simulators.

In 1992, he started to develop the PVsyst software for the study and simulation of photovoltaic systems. He developed a tool for the 3D Shading constructions, the simulation of stand-alone PV systems, and pumping PV systems (including research about modeling of batteries and pumps). He also conducted research for a specific model of PV modules on any available technologies.

In 1996, he participated in the development of a training course (PACER program of the Swiss Confederation) on photovoltaic installations for engineers. Between 2007 and 2011, he provided trainings on photovoltaic technology for engineers within the framework of INES (National Institute of Solar Energy, France).


André actively continues to develop the PVsyst software in order to incorporate the evolving needs of professionals and innovations in the PV industry. He provides a technical hotline for users and maintains the component databases closely related to the modeling results.

Other experience in solar energy

In 1985, Michel founded Dynatex SA to produce solar components and systems. From 1999 to 2004, he was a Swiss expert at the IEA (International Energy Agency) in the PVPS program. From 2001 to 2003, he participated in the European project INVERSTIRE to establish the specifications of the best storage technology for renewable energies.


Michel is the author (with Anne Labouret) of « Solar Photovoltaics » published by the IET (Institute of Engineering and Technology, Stevenage, UK), and of « Construire Ecolo » which present the main techniques for low-energy houses and in the field of renewable energies (puplished by Dunod in Paris).


Michel works mainly as an independent consultant and expert in photovoltaic engineering. He provides PV training on-demand through his company Dynatex.

Quality, environment and sustainability policy

PVsyst SA, route de la Maison-Carrée 30, 1242 Satigny, Switzerland – Phone: +41 22 753 08 01