How to boost algae building technology

If building owners, users and professionals are to accept any innovative technology, they need to understand its potential benefits. Without such understanding, it is less likely to be taken up.

Having looked at how algae can be used in building facades as a sustainable way to generate heat and biomass for various purposes, we asked a range of built environment professionals to identify issues that might occur in the uptake and use of algae building technology (ABT).

A total of 23 highly experienced, qualified professionals in design, regulation, engineering, construction, valuation, property management, town planning, facility management and building operation in New South Wales, Australia, were invited to take part in a research programme devised by the University of Technology, Sydney in 2016. The study was funded by the City of Sydney to gain a greater understanding of the drivers and barriers for ABT.

Participants were shown a video of the way ABT has been used in the BIQ House in Hamburg, Germany. They were then asked in a workshop to reflect on the issues they thought the technology would present for construction in Australia, and discuss them in greater detail individually in a 1-hour interview. They detailed the pros and cons of ABT, and raised technical issues relating to design, regulations, construction, and operation and maintenance.

If adopted on a large scale, ABT could also mitigate the urban heat island effect – where towns and cities retain more heat than surrounding areas – as well as reducing loads on energy infrastructure. Another potential advantage of the technology would be the sale of biomass to medical companies, where high-value algae are used in pharmaceutical manufacture, or to producers of health supplements, for example.

In terms of barriers, there is a risk that ABT will not perform as predicted and then merely be seen as greenwash rather than as an effort to improve buildings' environmental performance.

Other factors to consider are that algae production may be higher in countries with more sunlight. Meanwhile, as the technology is still innovative ABT is expensive because there are as yet no economies of scale.

Professionals also voiced fears about contamination in buildings from leaks because some algae contain hepatotoxins and neurotoxins, which are harmful to humans. Any damage or leakage could cause unpleasant odours as well. Even though ABT will necessarily be well-designed, well-constructed and well-maintained and the selection of algae will be carefully specified, the participants' reactions show that there is some way to go in educating professionals about the minimal risks.

Other technical factors needing consideration when designing PBRs include temperature, lighting, glazing, rates of dilution, water quality, pH, carbon sequestration, and the need to remove the oxygen that the algae produce.

The panels should be able to accommodate any settlement and movement in the liquid without the seals or facade connections failing, and the expected life cycle of materials should be comparable to that of conventional designs. Finally, the PBRs should be protected from accidental damage.

As the climate in Hamburg is very different to that of New South Wales, a major concern of participants about the replicability of the BIQ House was lack of evidence on biomass production in Australia. The implications of higher biomass production due to increased exposure to sunlight would require investigation to enable easier cleaning and ensure maintenance of ideal temperature, and the use of robotic scrubbers and computer monitoring should be studied.

PBR lifespan, durability and reliability are vital considerations, with numerous components including panels, piping, valves and fluid having to work in unison for optimum biomass production. Participants agreed that preventing leaks is a priority, and that PBR lifespan should be at least 20–25 years. They also proposed that automated control systems and artificial intelligence could help to recalibrate controls when weather conditions change unexpectedly.

All participants compared the performance and costs of ABT unfavourably with those of existing renewables. As ABT is new and there has been no large-scale uptake, the technology is perceived as expensive. Striking a balance between cost and efficiency would therefore be paramount, along with spreading awareness, educating professionals in designing, building and managing ABT, and developing rigorous guidelines.

Expensive, time-consuming and non-standard approaches would then be the only option to ensure buildings comply with the Building Code of Australia. For example, professionally calculated and reported proof of performance would need to be submitted to certifying authorities.

Participants discussed the possibility of developing market incentives and requirements for on-site energy technology, such as making it mandatory on certain types of development: large residential schemes on brownfield sites could be required to be partially self-sufficient so they wouldn't have to use existing energy infrastructure, for instance.

Stakeholders also recommended that directives and guidelines on commissioning, operating and maintaining technology be developed to ensure health and safety. Promotion and education would also help change perceptions and increase acceptance and deployment of the technology on public buildings.

However, they did caution that retrofitted facades could add weight to existing structures. These would therefore need testing beforehand, while any additional structural capacity would increase costs.

Interviewees also noted that Australia lacks professionals who are sufficiently educated in the design, construction and maintenance of ABT.

Because algae adheres to surfaces, effective cleaning of PBRs and pipes is imperative, and participants expressed concern about how frequently this would be needed. As a result, stakeholders again reckoned that blueprints and guidelines would be necessary. They also proposed the use of green leases, as developed by the Better Buildings Partnership, containing clauses about ABT performance – with the caveat that operators need to be aware of the way weather affects the technology's efficiency.

Training and educating tradespeople and professionals in ABT maintenance will also be necessary, which may be onerous and more expensive than with other technologies. Without a blueprint, algae panel information and design guidelines are needed for all life-cycle stages, and it would be essential that manufacturers make no unsubstantiated or misleading claims. ABT needs to be as reliable as conventional facade systems to succeed.

Many believe that the 21st century will be dominated by renewables and biofuels, so greater understanding of ABT's potential as an on-site energy source for buildings is needed. Stakeholder feedback shows the direction we, as researchers and developers of the technology, should take. It also emphasises the need to invest in testing and evaluating efficient PBRs suited to Australia's climate as well as in monitoring and decision-making software.

Resolving design and engineering issues is not the only way to encourage uptake, however: educating the public, and the professionals who design, install and maintain ABT, can demystify it and dispel concerns around the operation and benefits, building a technically sound community for maintaining and engineering installations.

Legally, a push to encourage renewable technology through subsidies could help promote adoption, as could showcasing ABT in public buildings to increase its exposure. Once tried, tested and evaluated, blueprints and design guidelines can be developed.

Related competencies include: Construction technology and environmental services, Sustainability