The efficiency of space solar cells: Cesi Inaugurates new production

Among the world leaders in photovoltaic technology for satellites and probes, the company has inaugurated its new production line and the new business unit, Cesi Space. A cutting-edge technology supported by Pnrr funds for space.

BY EMILIO COZZI

Luca Parmitano highlighted this in a video message from Houston: “At the heart of what we do in space is solar energy. Without it, space exploration would not be possible.” It’s no coincidence that the European Space Agency (Esa) astronaut described it as an “important day for the Italian space sector.” On March 13, Cesi, the Italian Experimental Electrotechnical Center, inaugurated its new business unit, Cesi Space, along with an advanced production line for photovoltaic cells designed for space applications. These sophisticated technologies are built to withstand the extreme environment beyond Earth’s orbit and could, in the future, even find their way onto the roofs of our cars.

This is a fusion of engineering excellence and applied innovation, part of the Italian Space Agency’s (ASI) Space Factory 4.0 program, reaffirming Italy’s voice in the global aerospace industry.

The space solar cell industry is undergoing a revolution. The reason, almost obvious by now, is the proliferation of commercial satellite constellations, which already number in the thousands and will continue to grow in the coming years. Cesi is among a select group of international players capable of producing high-performance solar cells: ultra-thin devices that convert 30% of sunlight into electricity, far surpassing the 20% efficiency of standard household solar cells.

Parmitano reiterated: “One of the four companies dominating this technology, the only one in Europe, is Italian.” A significant recognition, earned by Cesi through three decades of innovation.

Twenty Million, Private and Pnrr

Behind the new production lines is a €20 million investment in the manufacturing plant at the Milan facility, with more than a third funded by the National Recovery and Resilience Plan (Pnrr) through a public private partnership model. This initiative involves over 60 highly specialized technicians, including 30 new hires, demonstrating that the space sector generates jobs and expertise.

Ceo Nicola Melchiotti confirmed this: “Italian patents, Italian capital, Italian production chain, we are an excellence serving the country and Europe.”

Public financial support, particularly Pnrr funds allocated to space innovation, is proving to be a crucial factor in the success of initiatives like Cesi’s. The Italian Space Agency’s (Asi) Space Factory 4.0 program is a concrete example of how the synergy between the public and private sectors can accelerate technological development and ensure competitiveness in the international market.

Expanding Market Thanks to Private Constellations

The bar is being raised even higher for Cesi: the new production line will allow the company to triple its output, reaching 80,000 cells per year. These numbers are essential for a rapidly expanding market, as noted by Claudio Comparini, director of the Space business unit at Leonardo: “To be sustainable, satellites need to cost less, and we must have an industrial system that produces in different times and at different costs compared to the large-scale setup.”

“Our production capacity, almost exclusively focused on the Italian and European markets, which accounts for 15% of the global market, is already booked for the next three years. Now we are also looking at international markets,” adds Melchiotti.

Behind every Cesi solar cell is a crystalline dance of chemical elements and nanotechnology. Describing it is Roberta Campesato, scientific director of Cesi Space: “Our cells are not based on silicon but on a mix of gallium arsenide, indium phosphide, and germanium. We lay down 52 ultra-thin layers, some of which are monoatomic: each layer has a specific function to capture every wavelength of light and convert it into energy.” This technology not only improves efficiency but also makes the cells more resistant to the harsh conditions of space.

From Interplanetary Probes to Solar Cars

Cesi is no stranger to technological challenges: with a pedigree spanning from the certification of electrical equipment to the digitization of networks, as well as high-power systems for dams and submarine cables, the company has managed to adapt and anticipate the future. Its photovoltaic cells power space missions from Earth’s orbit to the depths of the Solar System, with probes directed at Mercury, Mars, and Jupiter.

But the future could bring this technology back to Earth, strictly speaking: “We are working on four-junction cells with 32% efficiency, and we aim for 35%,” explains Campesato. While the costs, still prohibitive for the domestic market, limit their use on residential rooftops, their application in solar cars is becoming a realistic scenario. The idea is to use ultra-high-efficiency cells paired with static concentrators capable of multiplying the collected light.

Space, Business, and Politics: A Growing Ecosystem

Cesi’s journey is proof that space is not just a scientific matter, but also an industrial and economic one. This is certified by Teodoro Valente, president of the Italian Space Agency (Asi): “Public support is crucial for accelerating innovation, but private involvement is key to the commercial sustainability of the sector.” The flow of European and national funding, particularly through the Pnrr, plays a strategic role in stabilizing the sector. “In the United States, Nasa’s role has transformed with the entry of private companies. In Italy, we need to consolidate a model that ensures the right balance between public support and private investment,” emphasizes Valente.

Indeed, in a global landscape where the SpaceX model has redefined paradigms, Italy is also refining its strategy: the space law, approved in the Chamber and awaiting discussion in the Senate, is a first step toward stronger governance of the sector, as Valente pointed out. And who knows, one day, after fueling interplanetary explorations, it might also help us travel on Earth, driven by the ambition that propels us toward the stars.