Jean-Louis Scartezzini: a life devoted to the sun

© 2023 EPFL Alain Herzog

© 2023 EPFL Alain Herzog

“I can’t even offer you a cup of coffee – I already packed up my coffee machine!” Prof. Jean-Louis Scartezzini, who has headed EPFL’s Solar Energy and Building Physics Laboratory (LESO-PB) for the past 30 years, doesn’t seem fazed by his upcoming retirement. We spoke with him about his long, successful career and some of the twists and turns along the way.

Retirement is the natural culmination of any career, and Jean-Louis Scartezzini is looking forward to his – he’s already got a number of hobbies and projects lined up to keep him busy. The EPFL professor almost missed his calling in academia, as he was initially tempted by a career in scientific journalism when he was a research assistant in physics. “In 1981, I worked on a Swiss radio program with Madeleine Caboche. I still have the cassettes at home.” he says. At the time, he also wrote scientific articles for the Swiss magazine L’Hebdo, taking up an offer by its founder Jacques Pillet. “After writing several articles and contributing to around 20 radio programs, I had to make a choice: either go on to complete a PhD or pursue a career in radio.”

Scartezzini opted for the PhD route and enrolled in a program at EPFL. He joined the Solar Energy Research Group headed by Prof. André Faist, one of the first scientists at EPFL to study solar energy. There, Scartezzini played an active role in designing a building with a heating system that ran on five times less energy than equivalent buildings – the first structure of its kind in Switzerland. This building housed EPFL’s Solar Energy Laboratory (LESO). “I helped set up the building’s instrumentation, which consisted of some 600 sensors installed in the ground, on the roof, on the building façades, in the offices – just about everywhere,” says Scartezzini. “At the time nobody believed in us, but we showed our idea could work.”

© 2004 EPFL Alain Herzog The LESO is a building full of probes

Scartezzini later traveled around the US to get a first-hand look at newly constructed solar power plants. His career-long effort to promote solar energy eventually ruffled some feathers – and even landed him on a watchlist held by the Swiss secret service.

The Archimedean Oath
Scartezzini graduated with Master’s degrees in physics from EPFL in 1980 and in geophysics from the University of Lausanne in 1981, getting the highest possible grade each time. “I was lucky enough to be asked to give the commencement speech at EPFL’s graduation ceremony,” he recalls. “I based my talk on the issues I felt strongly about, stressing that scientists have a duty to help build a better society and should refuse to conduct research that could have a negative impact.”

In the 1980s, nuclear power was considered to hold the key to the future, but Scartezzini believed there was another, more sustainable path to producing the world’s energy. His convictions ran against popular thinking at the time.

“Some of my professors criticized me afterwards for my speech,” he says. “Bernard Vittoz, who was then the EPFL president, didn’t agree with me but said that he respected my views. I’d like to think that my comments are what gave some people at EPFL the idea to draft an Archimedean Oath – ultimately published in 1990 – as the engineering equivalent to the Hippocratic Oath.”

© Jean-Louis Scartezzini participates at the Solar & Architecture Conference in Toulouse in 1982

A year of PhD research in the US
After completing his Master’s degrees, Scartezzini began a PhD program at the research group headed by Faist, who also served as his thesis supervisor. There he worked as a research assistant and delved into the mechanisms of solar energy, growing excited about its potential. “We were a handful of pretty adamant scientists. I got swept up by the group’s enthusiasm, and that has stayed with me ever since.”

As part of his PhD program, Scartezzini spent a year conducting research at the University of Colorado’s Solar Energy Applications Laboratory. That was in 1984. There he met some luminaries in the field, including George Oscar Löf, a pioneer in solar-energy research and the inventor of the first solar-powered home heating system – tested on Löf’s very own home.

© SCI, The Umbroiler parabolic solar cooker,
used with George Löf's daughter in 1955

In 1988, Scartezzini returned to the US as a postdoc fellow at the Lawrence Berkeley National Laboratory. This was just after the US began investing heavily in solar power during the Carter administration. “I toured solar power plants in New Mexico, Nevada and California,” he says. “There was incredible momentum for a while behind this kind of technology. Today we’re seeing that kind of momentum again.”

© Jimmy Carter Library, President Jimmy Carter inaugurates White House solar collectors,
June 20, 1979

Once back in Switzerland, Scartezzini was hired as an associate professor at the University of Geneva. Then in 1994, Jean-Claude Badoux, the newly appointed EPFL president, created the School’s first professorship in building physics and appointed Scartezzini to that position as a full professor.

Tracked by the Swiss secret service
Switzerland had five nuclear power plants in the 1990s and was one of the world’s biggest users of nuclear power. Renewable energy was barely on the radar. Scartezzini spent several years trying to persuade policymakers and other scientists of the benefits of solar energy. “Our ideas weren’t yet mainstream – it was like shouting into the wind,” he recalls. “We were seen as troublemakers or dissidents: people who wanted to stand in the way of progress.”

His contrarian stance led to an extraordinary series of events. “Back then I was president of the Swiss Solar Energy Society, and one day our secretary ran off with all our cash,” he says. “We later found out that the theft had been instigated by the Swiss secret service in order to weaken the solar energy movement. It’s true that some members of the Society were left-wing activists – some were so far left that they may have even been working for the USSR. We filed a complaint and our lawyer was Moritz Leuenberger, who went on to become a Swiss federal councilor.”

© "The foundation of the SSES" of which Jean-Louis Scartezzini was president 1987 – 1995

Today all that is behind Scartezzini, who now feels his efforts to promote solar energy as a cornerstone of a sustainable future have paid off. During his career, he trained nearly 50 PhD students who now work at universities worldwide and have started their own businesses, such as Solstis, Kromatix, E4tech Software, Estia, EPIQR Rénovation and ShadeMe.

Going where life takes you and discovering new things
As he enters this new phase of his life, Scartezzini is clear on how he’ll occupy his time. “I’ll do all those things I never had time to throw myself into. Being a professor means investing a lot of your time and energy, and sometimes sacrificing a bit of yourself along the way.” High on his agenda will be playing music with his sons (he’ll have to practice quite a bit to get up to their level), cycling with his friends (some of whom clock 10,000 km per year and ride up Mont Ventoux every summer), sailing (a sport he’s been practicing for over 40 years and which he plans to continue on Lake Geneva and in the Mediterranean) and astrophotography (a pursuit he’s dreamed of exploring).

© 2022 Sailor

But Scartezzini won’t turn his back on science. “I’m a researcher at heart and that won’t change after I retire,” he says. “I’ll still sit on the advisory boards for some cantonal governments’ climate strategies and be an active member of the Swiss Academy of Sciences in Bern. I’ll also continue to be involved with the Daylight Academy, which I helped found and later chaired. The Academy brings together scientists, engineers and architects from across Europe to promote daylight research.”