Last Updated Feb 28, 2017 · Written by Rob Schneider
We read a lot about harmful algae (or algal) blooms in our oceans and waterways. We read less about using algae blooms for sustainable building. Algae blooms have the potential to help address the problem of global warming and scientists are seriously studying ways to use algae blooms in the construction industry.
The University of Technology Sydney (UTS) and the City of Sydney have joined forces to look into algae as a building material. According to the researchers, algae promises to heat buildings, provide fertiliser for rooftop gardens and filter vehicle exhaust fumes. Algae is even able to produce electricity.
While the Australian studies are in their early stages, they already show promise. There are hurdles to overcome and public acceptance of algae as a building product may be slow, but algae could be the answer the world needs.
The City of Sydney has released an exhaustive feasibility study about the benefits and promise of using algae in sustainable design. The report begins by arguing that buildings today account for 30 to 40 percent of greenhouse gas emissions. While most of the emissions come from developed countries, they may be surpassed by developing nations in the near future.
Further increase in greenhouse gas emissions is not sustainable. It is vitally important to find more sustainable ways to build. Because algae is an organism, it has the capacity, like trees and other plants, to absorb greenhouse gas emissions and release CO2 into the atmosphere. It also can contribute to heating a building and when used as fertiliser for rooftops, can help keep buildings cooler and help nourish plant life on roofs.
Algae is a form of biomass. In addition to using algae in building, researchers have identified six ways algae could be used for a more sustainable future. They call them the "6 Fs":
The feasibility study covers the potential for algae's use as a "renewable source of energy for buildings in NSW Australia."
Algae is unstable and can't be used like bricks or cladding. The idea, as envisioned by researchers at UTS is to place algae behind sheets of glass. While that poses problems, the researchers received advice from the Australian Window Association. The association recommended using tempered and heat-resistant glass. Tempered glass would prevent the windows from breaking and heat-resistant glass would keep the algae at cooler temperatures. The cooler temperatures would prevent the algae from dying.
Having a facade made from algae may not sound appealing, but one researcher, Sara Wilkerson, disagrees. She says the algae is "visually appealing" and goes on to say, "I mean, how could you walk past a building with bubbling green wall panels and not stop to learn more about it? It’s eye-catching, it’s unique and it’s decarbonising the atmosphere, all at the same time."
Research in Australia is still in the early stages. The researchers say there may be as many as 300,000 species of algae, but they are only working with about 100 species. However, the Australian researchers are not alone. Overseas, more experiments with algae have been done and there is "demonstrated success of living algae bioreactors overseas."
In fact, biomass has been used before in sustainable building design. The BIQ House in Hamburg, Germany has 200 square metres of "integrated photo-bioreactors" (PBRS) in 120 panels, according to an article written by UTS associate professor Sara Wilkerson in the Fifth Estate.
The PBRs in the BIQ House transport biomass and heat to an energy management centre. The biomass is harvested there and the heat is used to heat hot water and warm the interior. It is also stored under the house. Algae biogas is used to power a "micro-turbine" which generates electricity for 15 apartments. It is able to provide one-third of the heat for all 15 apartments.
Hamburg is cooler than most parts of Australia. Heat may be a stumbling block in parts of Australia, but researchers believe they may be able to find an algae that tolerates higher temperatures. In the meantime, algae panels can be used in cooler regions of Australia.
The Australian government's Your Home: carbon zero, carbon positive website begins by saying a "long-term sustainable solution to global warming and climate change requires that we eliminate or substantially reduce the amount of carbon being emitted into the atmosphere from human (anthropogenic) activities. It can be achieved by creating carbon zero or carbon positive homes."
Carbon zero building has been accomplished. Carbon positive building design is the next step forward. A carbon positive building actually produces more clean energy than it uses. Algae may help carbon positive buildings a reality.
A carbon zero building makes use of solar panels to generate electricity. It also employs passive solar techniques and highly efficient windows (such as double glazed and low-e glass) and cladding to reduce heat transference. Carbon zero buildings have been with us for some time now. Hong Kong's first carbon zero building was built in 2012, but it was not the first.
Construction of the first carbon zero city began in 2008 in Abu Dhabi. The idea behind Masdar City was to create a carbon zero city capable of housing 50,000.
Carbon zero technology has been proven. The next step is carbon positive and that will require some sort of biomass to accomplish. Biomass is capable of converting polluted air into clean air. Algae can be grown in abundance and has the potential to help create a carbon positive building.
It is well-known that our rainforests are being destroyed at an alarming rate. The Amazon rainforest and rainforests in Indonesia and other countries are the "lungs" of the world. As they get destroyed and we rely more on fossil fuels, global warming occurs. Many scientists believe the only way to reverse the trend is to consume less and take the environment into consideration in our built structures.
Algae is relatively easy to grow and can grow in abundance. Hamburg's BIQ House is one example of an apartment complex that has successfully used algae in its building design, but it may be just the beginning.
Increasing numbers of architects, engineers and scientists are studying ways to create carbon zero or carbon positive buildings and other technologies. Solar panels were some of the first. They were prohibitively expensive when they were first designed, but have come down in price and are being used around the world.
Algae as a building material is currently in its infancy. UTS and the City of Sydney are hoping to have prototype panels ready by 2017. The prototype panels will help them monitor production and performance rates in New South Wales. More importantly, they will raise awareness of the technology and introduce algae as a building material to the general public.
We may not see algae being used as a building material for at least a decade, but hopefully it will catch on and become as cost-effective as other building materials. Like solar panels, algae building panels will pay for themselves over time and save money in the long run. A clean future is on the horizon, but we need to embrace it now. Our future and the futures of our children depend on it.