Algae Curtainwall
Algae can be harvested in building systems to be used as biofuel, or even sustenance for people.
Engineers from Germany and the USA have experimented with algae-infused curtainwall which generates renewable power from biomass. Algae growth is incurred by solar exposure, and the mature algae is then transported through a closed-loop system which uses the bio reactive processes to produce heat. This heat can be used as a biofuel to heat water and power-grids. Algae curtainwall is typically composed of four layers of argon-insulated glass, plastic, water, algae, a growth medium, inflow and outflow pipes and compressed air.
Algae is infused into a curtainwall system to create photobioreactor panels. The panels form a closed-loop system where pumps circulate the algae fluid from a plant room inside the building to the façade panels. Algae in curtainwall systems need to be fed, this can be accomplished with boiler flue. Micro-algae absorb daylight at 640 nanometres, and the remaining part of the daylight spectrum is transformed into heat.
The photosynthetic process of the algae is initiated by daylight and accelerated by the periodic release of pressurized air into the panels. Turbulence generated through this uplift technology stimulates the metabolism of the algae and subsequently increases the productivity of the system. The algae-harvesting systems can be fully automated. The excessive heat is processed and released by heat exchangers and used as biofuel.
The BIQ house in Germany was the first building constructed with a fully functional algae-infused curtainwall system in 2013. The panels in the curtainwall can rotate on their vertical axis for maintenance purposes. The frame is composed of aluminium and are 80mm deep in total. The glass itself has three cavities;an 18mm wide aqueous cavity is flanked by insulating, low-reflective glass. Piping is installed horizontally along an insulated duct that can be maintained through access flaps on the outer edge of the panels. Larger panels with bonded stiffeners are currently in the experimental phase. The Algae dome at Copenhagen's 2017 Chart Art Fair is another example of the potential for algae infused architecture.
Commercial Readiness
The only use of the façade has been seen in a pilot project in Germany. In order to commercialise this product, curtainwall systems with specific adaptations for this system would need to be produced (Castro-Lacouture, Chang, Dutt, & Yang, 2017).
Cost Analysis
The 30-year life cycle energy cost savings for a building retrofitted with algae pre-fabricated panels are estimated to be more than $10 million. Algae curtainwall panels provide cost savings compared to curtainwall with similar energy-saving attributes, such as triple-glazed panels or panels with low-emissivity coatings (Kim & Patel, 2018).
