Architects have been experimenting with the potential of building envelopes for years. Now, Arup has an interesting, Zumtobel Group Award-nominated proposal: the Solarleaf bioreactor. Developed in collaboration with SSC Strategic Science Consult GmbH and Colt International GmbH, this thin, 2.5 x .07 meter panel, when attached to the exterior of a building, is capable of generating biofuel - in the form of algae - for the production of hot water. More efficient than electricity and more sustainable than wood, algae is ideal kindling for producing heat, especially since it can be grown on-site. Moreover, the water in which the algae grows also collects solar energy, providing an additional supply of heat. More details on this sustainable innovation, after the break.
The simplicity with which Solarleaf panels work is admirable. The panels are comprised of just four glass layers. The inner two form the 24-liter cavity that holds water and algae, while the outer two form argon-filled insulation barriers that prevent heat loss. The exterior faces of the bioreactors are anti-reflective glass to maximize solar heat gain. The algae matures within the panels, asborbing CO2 during the photosynthesis. Compressed air is piped into the reactors at intervals to encourage that process The air, combined with the water and plastic scrubber particles suspended in the water, also keeps the interior glass of the cavity clean. Both the algae and the heat from the panels' water can be drained from the bioreactors and harvested by the closed loop system that accompanies Solarleaf's installation.
In addition to providing renewable energy, the translucent panels can act as a shading system for the house’s windows, and provide a reasonable increase in acoustic insulation. This was recently brought to the world's attention in April of 2013, at Germany’s International Building Exhibition in Hamburg. Arup’s BIQ house incorporated approximately 200 square meters of bioreactors on its façade.