“We have chosen TOPCon technology for our future French solar cell gigafactory,” says Pascal Richard de Carbone.

Just three months after the company announced its intentions to build a mega-factory for the production of photovoltaic cells and panels in France, Carbon has chosen its solar technology. On May 13, the startup announced that it has joined forces with the international solar energy research center ISC Konstanz (Germany), which owns patents for tunneling oxide-passivated contacts (TOPCon) technology. For Industrie & Technologies, startup co-founder and president Pascal Richard looks back on this milestone and, more broadly, on an ambitious industrial project that he is pursuing with conviction.

Industry & Technology: On May 13th you announced that you have chosen to partner with ISC Konstanz. Why is this such an important step?

Pascal Richard: In partnership with ISC Konstanz, we decided to produce the TOPCon technology, for which this research center holds patents. This is an important step: once the technological choice has been made…go ahead! All production processes, the size of the site where we want to be located, the technical specifications and therefore the choice of manufacturers who will produce our equipment, stem from this choice! We fully assume this, and we are in the process of explaining it to the market, investors, the state, Europe, etc. our solution.

Why did you choose to rely on TOPCon technology over Passive Radiator Rear Contact (PERC) or heterojunction solar cells?

We are listening to the market and one of the main standards in 2025 will be TOPCon technology. We can think of it as an improved version of PERC: cell efficiency increases from 22% to 24%. This is a lot, given the production of electricity for more than 30 years! In addition, TOPCon technology has the advantage of being able to evolve towards IBC. [cellules solaires à contact arrière interdigité, ndlr], without having to invest heavily in new equipment.

Another flagship technology used by Carbon’s competitors is the heterojunction cell. It’s good technology, but we’ve seen TOPCon move towards a more robust international rollout in the coming years.

Other players have mastered the TOPCon technology. Why did you choose ISC Konstanz?

The proactivity of ISC Konstanz will allow us to maintain our flexibility, which is a distinguishing factor for Carbon. In addition, there are already bases that manufacture ISC Konstanz cages internationally (in India and China, as well as PERC in Turkey), so this is a strong support.

We are also collaborating with the Île-de-France Institute for Photovoltaics (IPVF), based in Paris-Saclay, with its teams from CNRS, Total Energies and EDF, where we are likely to work together on solutions for tomorrow’s technologies. . Surrounded by two independent structures – IPVF and ISC Konstanz – we have a strong team that promises big things in record time!

What skills do you need to learn to produce photovoltaic cells and panels?

There are three professions in Carbon. First, the production of ingots and wafers: polysilicon is smelted to create ingots, which are then very finely sawn to make wafers. Secondly, cell production: we integrate the TOPCon technology into the plates. This step takes place in a clean room. Finally, the cells in the panel are assembled.

The production of cells and panels will definitely be located in Europe, but what about the supply of raw materials?

The main strategic raw material is polysilicon, which is produced from quartz, coal and wood. Unlike other minerals, quartz is not only found under China or the Congo, but is one of the most common materials in the earth’s crust. There are several players in Europe who produce polysilicon, such as the German chemist Wacker. On paper, nothing is stopping us from recreating a fully integrated solar industry in France and Europe!

In addition, there are still areas of innovation in the production process that Carbon is working on a lot: at the moment, we lose 40% when converting ingot to wafer! We want to reintegrate these losses into the process to limit dependence on the market. Finally, remember that the panel at the end of the chain is 95% recyclable. We are also working on strategies for refurbishing solar panels at the end of their life to recover some of the components that will go back into the process.

Is the market receptive?

We are in a very advanced discussion process with clients. The big difference with other startups – especially battery gigafactories – is that we won’t have a single client to get involved. We want to serve the market.

About two-thirds of Carbon’s output will be sold (in panels) to large energy companies with very large power generation needs. The last third will be for companies that assemble panels – there are about fifty in Europe – to which we will sell solar cells. It’s kind of B to B industry, where we will jointly create a European proposal.

Why are there no other initiatives of this magnitude?

Because investments are very important! We aim to be among the top 10 solar panel manufacturers in the world, which currently does not include Europeans. In 2030, we plan to install 20 GW of panels, which requires an investment of at least 5 billion euros. We have the first stage with a capacity of 5 GW in 2025, which represents an investment of 1.2 billion euros. Achieving such production volumes is necessary for competitiveness!

This is a speed race. You need to be able to make decisions quickly, maintain some flexibility for future fundraising. This is an entrepreneurial approach that has never been seen before!

So it’s a hell of a risk…

We initiated this reflection in 2020 together with Pierre-Emmanuel Martin, president of the Terre et Lac group. [producteur d’électricité solaire et développeur de projets solaires, ndlr] and Philippe Riviere, President of ACI GROUPE [ETI Française de sous-traitance industrielle, ndlr]. Observing the difficult situation with the supply of solar panels to the European market associated with the Covid pandemic, but the trend was already before, led me to the next question: how to repatriate part of the cost? The creation of Carbon imposed itself.

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