“The issue of photovoltaic efficiency is a focus of research”

Emeritus researcher at the CNRS, visiting professor at the Collège de France in 2021-2022, Daniel Lincot has worked on solar energy for more than forty years. He looks back on this long maturation.

The development of solar energy has been very slow for forty years. And has been extremely fast for two years. How to explain it?

What is spectacular in the field of photovoltaics is that the first efficient cells were discovered in 1954 thanks to silicon and that in 1958 they already equipped the first satellites. At that time, there was no real price barrier, space worked for solar power a bit like Formula 1 for cars. In 1958, for the first satellite, the power was of the order of a few watts. Then, and since that date, growth has been exponential with an increase in installed power worldwide of 30% per year, but this has remained invisible for a long time vis-à-vis other energies, in the thickness of the line as we say , until she suddenly appears in the landscape, like today. For a long time, solar was considered a fad and we were told: “You are drawing plans on the comet! »

Why is France, which was a pioneer, so far behind today?

France has long remained in the lead with the United States and Japan, far ahead of Germany. Companies in the 1960s or 1970s were pioneers – I am thinking of RTC, the ancestor of Photowatt, which is in difficulty today. In the 1970s, faced with the oil crisis, nuclear power appeared to be the best solution, and solar power returned to a form of utopia or fad. There certainly was a solar energy commission, just as there was an atomic energy commission, but unfortunately it fizzled out. The 1980s, under Mitterrand, marked the beginning of a long crossing of the desert, until the mid-2000s. It was a period when in Germany, on the contrary, credits increased and the energy of researchers was used to increase yields and lower costs. Industrial photovoltaics took off at that time. The same thing will happen as for flat screens, mobile phones or electric vehicles. At first, it is so expensive that development seems impossible. Then the prices fall at the same time as the processes are industrialized. Thanks to this, solar energy has become very competitive economically.

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