There’s a saying about people who build glass houses.

They make a big impression at the World’s Fair.

Last summer, at EXPO-2017 World Exhibition in Astana, Kazakhstan, Germany exhibited a glass house, its walls and roof comprised of glass tubes that were cultivating algae. The goal: to highlight algae’s potential as a natural, renewable energy source.

“We want to raise awareness that algae can be cultivated and put to good use, and that they provide the energy of the future,” said Sander Hazewinkel, an algae specialist and chief commercial officer at LGem, a Dutch maker of photobiorectors that conceived of and built the glass house. “What better way than with a futuristic design. So we modeled the photobioreactor in the shape of a house. It’s supposed to remind people of everyday life.”

Algae needs little more than sunlight and CO2 to grow. Some grow in open system photobioreactors (PBRs) – basically open ponds. Others are closed systems made of clear tubes that offer a more controlled environment. While both plastic and glass are used, glass features superior light transmittance, it’s easier to clean, and it lasts longer than plastic.

But most photobioreactors don’t look like houses. They tend to be emphasize function over form – with glass tubes running in long curving rows that look like the shelves in a library. That’s what makes Hazewinkel’s project unique – it required several “impossible” bends in glass tubes, done by glass blower VBGL. The project was a fairly complicated one, with at least nine companies having a role in the design, manufacturing, shipping, and construction of it. The end result drew the attention of The New York Times.