The world’s first approved system (photobioreactor) for growing microalgae as a food product in the urban space can be found on the building façade of the Berlin company headquarters of MINT Engineering GmbH.

The system comprises a connected pipe which is filled with water. Microalgae – for instance chlorella or spirulina – grows inside. This algae is so small that one can only see it by its green colour. The trick: With light from the sun, CO2 bonds in biomass and produces oxygen. The algae is harvested using a centrifuge. Thus it is possible to produce up to one kilogram of dry substance per day. It is even suitable for food production. The system also happens to serve as a thermal solar unit and can be used today to economically and feasibly provide water for heating and hot water for large systems.