Solar Curtain

Many designers develop projects not on their own initiative, but as commissioned works. However, a client generally has a relatively precise idea of the intended result. For designers to implement their ideas freely and independently they must take the initiative — that’s usually how the most exciting projects arise.

For example, the exterior Solar Curtain, which Petra Blaisse and her Amsterdam-based office Inside Outside have been working on since 2002. The impetus for its development was a competition for mobile HIV clinics. Blaisse proposed a mobile curtain that could make solar energy available to heat water or run refrigerators. She had the idea that curtains could be ideal carriers for solar cells. It should be light enough so it can be transported easily and then attached to trees or tents.


Blaisse did not win the competition, but in 2014, when the Textielmuseum Tilburg asked whether Inside Outside were interested in a research collaboration, she took the opportunity to further develop the curtain. Here her research interest was not only the solar cells, but especially the textile itself. Again and again, new patterns were made in an iterative process to progress from the idea to a working prototype. In the Textielmuseum Tilburg and the designer’s workspaces, one can get an understanding of the development process with more than 20 patterns in varied colors, materials, and properties. Tests were run on how thin metal threads could be worked into the knitted fabric to transmit the electricity generated by the solar cells. One problem was the materials’ properties. While knitted fabric is elastic and stretches under tension, metals such as silver, gold, or copper cannot change in length. The knitting needlesquickly broke under the strain. A new metal thread that could withstand various conditions had to be found.

For designers to implement their ideas freely and independently they must take the initiative.

To capture the sun’s rays, the solar cells are placed diagonally in small bags made of a specially developed fabric that is thin enough for the solar cells to capture enough sunlight. Unlike the classic curtain, the Solar Curtain is not a two-dimensional, but a three-dimensional object. The knitting patterns are created by a computer program. By now, the first prototypes of Solar Curtain were being produced with a 3D knitting machine. Inside Outside continues to refine the curtain. The company is currently working on pliability, so that the curtain can be folded and draped together. And storing the energy without loss still presents a challenge.

The Solar Curtain is an aesthetic, ecological product that shows how previously unused surfaces can be discovered as a resource and then utilized. The curtain is not yet a marketable product, but rather is the interim result of a long-term research project that the designers have initiated. That takes courage and perseverance — because in design as in other fields, research is a long process of experimentation and improvement.

There’s still a long way to go before the Solar Curtain can be mass produced. The research the designers are conducting has its limits. Designers cannot solve all the technical issues alone. Blaisse is currently pursuing further collaborations with scientists and companies. Perhaps in the future the Solar Curtain will eventually be an everyday utilitarian object — perhaps this research will also lead to the development of many other products.

Friedrich von Borries, born in 1974, is an architect. He teaches Design Theory at the Hochschule für bildende Künste in Hamburg and runs the Projektbüro Friedrich von Borries in Berlin. The relationship between design and social development lies at the heart of his work, which exists in the border zone between urban planning, architecture, design, and art. “As scholars, we try to understand the world. As designers, we try to change it.”