Smart people, a wealth of knowledge, and the spirit of innovation –
that's what we've been about for more than 30 years.

About us


We are a small, independent and interdisciplinary team of experts, and our main area of expertise is in photovoltaics. We develop projects, advise companies and authorities, and continually produce innovative ideas that we see through to fruition. We do not sell any products, and instead of provide services in form of consulting, planning and project support. We also engage in information, training and lobbying work in the fields of energy efficiency and renewable energies.

The photovoltaic segment has seen massive development in the past 25 years – since TNC was founded – and its future potential is still far from being exhausted. We do our part to make suer this potential is harnessed to the full.

We are strong

The TNC and Effienergie AG team consists of engineers, architects, energy consultant, and specialists in photovoltaic systems, building renovation and metrology. Together, we have many decades of experience, and we bring a passionate commitment to renewable energies to each new project.

Thomas Nordmann

Telefon +41 (0)44 991 55 77

Company founder, CEO, and the driving force and soul of TNC. A photovoltaic pioneer from the very outset. Thomas Nordmann (born in 1952) has been working in the field of solar power since 1974. He es the founder and CEO of TNC Consulting AG and chairman of the Board of Directors of Effienergie AG.


Christian Dürrenberger

Telefon +41 (0)44 991 55 77

Dipl. Arch. ETH, NDS Softwareing. FH. Christian is responsible for the planning and implementation of processes, and for the statistical evaluations for Effienergie AG. At Effienergie AG, he is project manager for the various ProKilowatt programs.

Stephanie Fehling

Telefon +41 (0)44 991 55 77

Since 2003, she is the assistant of the CEO, handles the coordination and organization of various tasks at TNC, communication and webmaster. She supports the management of Effienergie AG, is responsible for the office of the Zürichsee Solarstrom AG and care of the shareholders.


Stefan Haas

Telefon +41 (0)58 680 40 51

Dipl. Arch. ETH. Head of the processing center of the Effienergie AG, responsible for staff and coordination, organization of procedures and technical handling of applications. He is energy consultant and “GEAK” expert.

Nadine Kunz

Telefon +41 (0)44 991 55 77

Since 2012 Nadine Kunz is responsible for accounting and HR matters at TNC and Effienergie AG.

Ralph Lingel

Telefon +41(0)44 991 55 77

As a Dipl.-Ing. Maschinenwesen Ralph Lingel is main-responsible for the TNC project development TNCALL.

Thomas Vontobel

Telefon +41 (0)44 991 55 77

Dipl. El.-Ing. FH, as project engineer responsible for the wide-ranging photovoltaic projects at TNC, ZSSAG und der Hydrodun AG as well as for IT issus. As a PV engineer, he will undertake the planning, execution and operation of PV systems as well as cost optimization, analysis of operating costs, performance and yield of PV systems.


We are well connected

TNC is part of a close-knit network of various companies and activities.

Effienergie AG

Effienergie AG, a fully owned subsidiary of TNC, focusses on the issue of energy efficiency on buildings.


Egon AG

TNC is one of the founders an shareholders of Egon AG. The company’s name comes from the German “Energie im Gebäude online” – “energy in buildings online”.


Hydrosun AG

HydroSun AG combines hydroelectric and floating photovoltaic systems “Waterlily” to hybrid power plants. The synergy potential of the energy sources sound an water are thereby fully exploit. HydroSun could doubled the capacity of hydroelectric power plants on a significant scale or even double.



Die Zürichsee Solarstrom AG (ZSSAG) is the first solar power network around Lake Zurich, and constructs large solar systems on the roofs of a wide range of buildings in the region


Forum Energiespeicher Schweiz FESS

TNC is partner of the 2016 newly founded “Forum Energiespeicher Schweiz FESS”. Thomas Nordmann is head of the core team and spokesman of the economy.


International Energy Agency, IEA

The International Energy Agency IEA is a cooperation platform in the field or research, development, marketing and implementation of energy technologies. Thomas Nordmann heads a working group looking at the performance and reliability of PV systems.



TNC is Solarprofi® at Swissolar

Solarprofis are qualified experts who advise and assist in the realization of solar power systems.

Solarprofi companies are carefully examined by Swissolar for their training and practical experience. The quality lable “Die Solarprofis” is also supported by EnergieSchweiz.


25 Jahre TNC

Impressionen zum Jubiläumstag «25 Jahre TNC»

30 Jahre TNC

Energie Zukunfts-Werkstatt am 10. November 2015