Hamburg is home to the world's first house to supply itself with energy via a façade of photobio collectors. Inside, microalgae produce biomass and heat. Can this be an answer to tomorrow's energy challenges?
The Hamburg district of Wilhelmsburg is developing into a laboratory for sustainable architecture. This is also where the BIQ "Algae House" was built as part of the International Building Exhibition - the very first of its kind.
The special feature of the otherwise not overly conspicuous five-storey residential building is its façade. On the sunny side, a total of 200 square metres of plate-shaped, translucent collectors are installed. Pre-stressed panes act as thermal insulation and at the same time as sound insulation - in order to make the best possible use of solar radiation, non-reflecting white glass is used on the front side. This way the light is not reflected and as much of it as possible falls onto the collectors. Many thousands of microalgae "live" in its interior, which are supplied with liquid nutrients and CO2 via a water cycle. The algae multiply until they are transferred to a special technical room for harvesting. The resulting biomass is used in an external plant for the production of biogas. In addition, the façade absorbs the light not used by the algae and produces heat from it - this is either used directly for heating or hot water or temporarily stored in the ground.
The result for a pilot project is more than respectable: With a yield of 15g dry matter per square metre and day, a net energy gain of approx. 4,500 kWh per year can be achieved when converting biomass into biogas - thus the façade could completely supply a family of four with bio-electricity.
Martin Kerner and his company SSC Strategic Science Consult operate the bioreactor facade at the BIQ and explain more about the background and function of this unique technology in a video interview.