In Gelsenkirchen, a short distance from Duisburg in the heart of the German Ruhr, stands one of the flagship facilities of the Vaillant Group, a German brand known for its technologies dedicated to domestic comfort. The company produces and sells heat pumps, solar panels, systems for combined micro-cogeneration installations and gas-fired boilers.

Founded by Johann Vaillant in 1874 in Remscheid, Germany, it remains family-controlled to this day. With more than 12,000 employees and a turnover of 2.3 billion euros in 2012, Vaillant develops and manufactures its products across 14 production units located in eight countries.

Among the strengths of the German brand is the production of solar collectors (or solar thermal panels), a renewable energy technology that harnesses solar energy for the production of domestic hot water and for heating.

Assembling a solar thermal panel, step by step

It all begins with copper, the conductor material par excellence — flexible and malleable — which is bent and folded back on itself to form a coil, the true circulatory system of the collector, since the water to be heated will flow through it.

The coil is then welded to the heat-absorbing plate via 13,000 points — the heart of the system — by means of a laser, and is then ready to be tested.

From here, the process moves to another line, where six fully automated robots operate, capable of completing the panel assembly. Six mechanical arms with humanoid movements, able to complete 280 panels a day — around 70,000 a year.

The process starts with the steel frame, which comes in two colours depending on whether the product is destined for northern or southern Europe. From here, the arms fit the base, while the only manual operation involves installing the copper collector previously welded to the absorber.

The next step sees three robots working simultaneously, impressive for their precision and freedom of movement. One applies adhesive to the base using a kind of small brush, while another, using special suction cups, installs the top cover of the solar panel. Finally, the last one seals the collector by removing the excess air, leaving it ready to be packaged.

The panel will be paired with a system designed and built by Vaillant to become a fully fledged solar station, capable of delivering an extremely efficient, sustainable and advanced technology.