A Polish start-up could install revolutionary but inexpensive solar panels on windows

Unfortunately, solar panels, while efficient energy sources, cannot be installed everywhere. On the one hand, it helps if the panels receive at least four hours of direct sunlight per day. On the other hand, these panels are heavy; the tile-roofed structure of a residential house can handle it, but what about surfaces that don’t? How do we install solar panels there? A Polish company has found a solution to this.

The answer so far has been the disappointing “it’s not possible” but in recent years, perovskite solar systems, more specifically their plans, have received increasing attention. Perovskite is an oxygen-bearing mineral that, due to its structure, absorbs light very efficiently, so solar cells made from it can also outperform conventional silicon-based structures.

It also has lower manufacturing costs and weight, so it would theoretically be inexpensive to cover surfaces that are currently impossible - it is not difficult to grasp the impact this theoretically would have on the sustainable energy industry. But it's no coincidence that we use the term “theoretically”. The perovskite-cell solar panels have been rather unstable, and also, their efficiency has not caught up with the more mature technology of traditional panels. Furthermore, perovskite is a toxic mineral that, combined with its instability, carries health risks.

Although researchers say it has long been clear that perovskite is the way of the future, and no solar technology has evolved so dynamically (since it actually began to advance in 2009), not all of its challenges have been solved yet. Or have they?

In May, the Warsaw-based Saule Technologies opened its 5,000-square-metre perovskite solar plant in Wrocław, the historic capital of Silesia. The Polish start-up is based on research by co-founder and technology leader Olga Malinkiewicz, who back in 2013, as a student at the University of Valencia, developed a process for covering easily bendable foil sheets with perovskite. Malinkiewicz published her results as the first author in the prestigious Nature Photonics (a journal with an impact factor of 38, which roughly means that what is published there is scientific scripture), which has been cited more than a thousand times since December 2013.

Perovskite. Photo: Getty Images

Malinkiewicz’s accomplishments were also recognised by MIT and the European Commission, and in 2014, she co-founded Saule Technologies (Saule S.A.) with two colleagues, into which Japanese investment guru Savada Hideo poured money a year later, though the exact amount was not disclosed by the parties. Furthermore, in 2020, Poland-based Colombus Energy invested an additional € 10 million, and when the plant was opened, a € 250 million co-operation package was also signed with MVGM Group.

So the money is there, and expert opinions also assert that Saule now employs seventy people and is experimenting with “solarpaneling” shades mounted on windows. The company has already signed its first commercial order, which is scheduled to be completed later this summer. Of course, their products still have not achieved the goal that the company set itself: their one-meter-wide solar cell operates at 10 percent efficiency, which is only half the average 20 percent result for silicon panels of the same size.

Although perovskite might bring even higher efficiency, due to the previously-mentioned instability, this remains a dream for the time being, and Malinkiewicz is aware of this. However, according to the researcher, this does not matter, as the thin film made of artificial perovskite is so cheap that it will still be worth switching.

So much so that Saule is going public this year: it will be traded on NewConnect belonging to the Warsaw Stock Exchange, thus the results will be made public from now on, meaning there is a good chance of hearing quarterly in so-called investor calls if the company has succeeded or failed to reach various ambitious milestones.

Of course, the the Polish start-up is not the only company that has discovered perovskite for commercial use. The British company Oxford PV coats silicon solar panels with the crystal, thus increasing the efficiency of the structures to an average of 29.5 percent.

Cover: Getty Images