Underhyped Tech - Algal Photobioreactors
This is a deep dive into one of our nine underhyped frontier technologies for development.
The full exploration will be released on April 23rd. Sign up to the launch event here.
Cultivating algae at scale in an enclosed system for clean energy and carbon capture
Algal photobioreactors (PBRs) are one of those technologies that quietly do a lot—but rarely make headlines. That might be because they sit at the intersection of biology, engineering, and chemistry. Or maybe it’s because they involve green slime in tubes. But look beyond the surface, and you’ll find something surprisingly powerful.
From generating clean energy to purifying water and improving nutrition, this overlooked technology is already proving itself in projects worldwide. It’s especially promising for places tackling multiple challenges at once—like energy access, food insecurity, and climate vulnerability.
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An algal photobioreactor is a closed system—often a network of transparent tubes or panels—that cultivates microalgae. These systems create the ideal environment for algae to grow with the right mix of light, CO₂, nutrients, and temperature to maximise growth. Unlike traditional open-pond cultivation of algae, photobioreactors minimise contamination, improve biomass yields, and allow precise regulation.
These systems can be constructed from plastic, glass, or stainless steel, with designs ranging from tubular and flat-panel reactors to fermenter-like units. Some incorporate LED lighting to ensure consistent illumination, further enhancing algae productivity.
Algae might not look like much, but they’re mini powerhouses. They grow incredibly fast, absorb carbon dioxide more efficiently than trees, and can be turned into biofuels, fertiliser, food, or even building materials. Due to the enclosed system technology, PBRs reduce contamination risks and allow precise control, making them suitable for all settings—urban rooftops, rural farms, or industrial sites.
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Many of the challenges facing lower-income countries—climate change, water pollution, food insecurity, reliance on fossil fuels—don’t have a single solution. That’s where technologies like PBRs come in. They’re modular, multi-purpose, and potentially regenerative.
Some of the things they can already do:
Capture carbon: Algae absorb CO₂ quickly (even quicker than trees), making PBRs a natural fit for low-energy carbon capture.
Produce clean fuels: Algal biomass can be processed into biofuels or biogas, supporting local access to renewable alternatives to fossil fuels.
Boost nutritional security: Species like Spirulina and Chlorella are rich in protein, vitamins and essential fatty acids—providing a sustainable source of nutrition.
Purify wastewater: Algae help purify wastewater by removing nitrogen, phosphorus, and heavy metals, making the water safe for reuse in agriculture or ecosystems.
Purify air: Algae release oxygen and absorb pollutants, improving urban air quality.
Improve soil: Leftover biomass can be used as fertiliser, enriching soil health and reducing the need for chemical alternatives.
This versatility is key. In places where infrastructure is limited and resources are stretched, technologies that can do more than one job are especially valuable.
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Despite their vast potential for biofuel production, carbon capture, and food security, algal photobioreactors remain underutilised. They can be integrated into urban, rural, and industrial settings to provide sustainable solutions for energy, nutrition, and environmental restoration.
However, limited investment, high initial costs, and scalability challenges have slowed widespread adoption. For the Global South, where energy access and food security are pressing concerns, PBRs offer a decentralised and regenerative solution, but logistical barriers and lack of local expertise hinder implementation.
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Algae are incredibly versatile. They can be used to produce clean energy, purify water, enrich soil, improve air quality, and even serve as a nutritional supplement.
They offer a sustainable energy source. Algae can be turned into biofuels, providing a renewable alternative to fossil fuels—while also capturing CO₂ and supporting climate resilience.
They help restore ecosystems. Algae can reoxygenate water, absorb pollutants, and play a role in carbon sequestration—making them a natural fit for bioremediation.
They scale well. These systems can be adapted to many contexts, from small setups serving local communities to larger industrial operations.
They grow fast. Algae grow much quicker than conventional crops, making them an efficient source of biomass with high yield.
Different systems for different needs. Simpler, semi-closed systems are easier to run and more affordable. Fully closed systems are more productive and reduce contamination risk.
Some species do even more. Certain microalgae and cyanobacteria are especially efficient—optimising space, producing more oxygen, and even supporting carbon-negative outcomes.
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While algal photobioreactors show promise, there are some important challenges to keep in mind:
High upfront costs
These systems can be expensive to build and scale. Without financial support, they may be out of reach for many communities or organisations.Energy use
Photobioreactors often rely on artificial lighting and climate control. If these aren’t powered by renewable energy, the environmental benefits may be reduced.Water and space needs
Some designs require a lot of water or land, which can be a problem in areas facing resource constraints or competing land uses.Contamination and system stability
Keeping algae cultures healthy over time can be tricky. Invasive species, unwanted microbes, or biofilm buildup can throw systems off balance—especially at scale.Complex processing
Turning algae into usable products (like fuel or protein) often requires specialised equipment and expertise, which adds cost and complexity.Dependence on reliable inputs
Consistent access to CO₂, nutrients, and processing infrastructure is essential for these systems to run efficiently.Ecological risks
If non-native algae escape into natural environments, they could become invasive or disrupt local ecosystems.Methane emissions
Some algae species release methane, which is a potent greenhouse gas—an important consideration for climate impact.Efficiency limitations
Not all systems are productive enough to justify large-scale deployment yet. But new techniques are improving efficiency and bringing costs down.Scaling is still hard
Going from pilot to full-scale operation often requires significant infrastructure, investment, and long-term planning. -
Several shifts are making algal photobioreactors more viable than they used to be — especially in settings where climate, food, and energy challenges overlap:
Advances in bioengineering
New algal strains are being developed that grow faster, produce more biomass, and are better suited to different environments.Circular economy approaches
PBRs can be linked to other systems—like wastewater treatment or industrial CO₂ capture—turning waste into valuable resources.Smart agriculture integration
Sensors and automated controls are helping monitor growth conditions in real time, making it easier to optimise algae production with fewer inputs.Supportive policies and carbon markets
Government incentives for carbon capture, renewable fuels, and bioproducts are helping drive adoption—especially where carbon credits can be earned.Traditional knowledge and local practices
In parts of Asia and beyond, algae cultivation has long been part of farming and food systems. That knowledge can inform more context-appropriate, resilient solutions.Sustainable materials innovation
Algae are being used to make biodegradable plastics, textiles, and inks—expanding the range of commercial uses and aligning with circular economy goals.Water system integration
When combined with wastewater treatment, PBRs can clean water while producing biomass—offering both environmental and economic value.Ethical markets and green demand
Consumer interest in sustainable, ethical products is growing—creating new opportunities for algae-based goods, from nutritional supplements to biofuels. -
While the technology holds promise, several external factors still make it hard to deploy algal photobioreactors at scale—especially in lower-resource settings:
Limited awareness and expertise
Many organisations and communities simply aren’t familiar with what PBRs can do—or how to design, operate, or maintain them.Uneven supply chains
Key materials like CO₂ sources, nutrients, and reactor components can be hard to access, particularly in parts of the Global South.Regulatory grey areas
Unclear or inconsistent policies on algae-derived fuels, foods, and materials can delay or discourage investment and innovation.Market hesitation
Consumers and industries can be wary of algae-based products—due to perception, cost, or lack of understanding—which slows demand and commercial uptake.
Curious examples: what’s already happening?
Case Study no. 1
Algae-Based Carbon Capture at Scale in Morocco and Hong Kong - Startup
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Current carbon capture technologies, such as Direct Air Capture (DAC), require high energy inputs and costly infrastructure, limiting their large-scale implementation. Simultaneously, ocean acidification and rising CO₂ levels threaten marine ecosystems and global climate stability. Finding an efficient, nature-based method to capture and store carbon while enhancing environmental resilience is a growing priority.
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Brilliant Planet and ALcarbo are pioneering algae-based carbon sequestration, using different approaches to enhance CO₂ capture efficiency. Brilliant Planet operates large-scale algal raceway ponds in Morocco, cultivating native strains that absorb CO₂ up to 50 times faster per hectare than temperate forests, while also deacidifying seawater. The carbon-rich biomass is dried and buried for long-term storage, preventing its release back into the atmosphere. ALcarbo, based in Hong Kong, focuses on high-efficiency photobioreactors (PBRs), using controlled environments and genetic selection to cultivate algae strains that fix carbon up to 12 times faster than wild-type species.
✔️ Large-scale raceway ponds and optimised bioreactors accelerate CO₂ absorption rates.
✔️ Brilliant Planet is scaling its facility to capture 100 tons of CO₂ annually by 2025, with a long-term target of 270,000 tons per year.
✔️ ALcarbo’s engineered algae capture three times more CO₂ than conventional strains, with plans to expand to 2,900 bioreactors.
✔️ Brilliant Planet removes CO₂ from seawater, reducing acidification and benefiting marine ecosystems.
✔️ ALcarbo’s nanobubble-enhanced bioreactors improve CO₂ dissolution, while algae-based capture is significantly less energy-intensive than DAC.
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Provides a low-energy alternative to conventional carbon capture technologies.
Mitigates ocean acidification, supporting marine biodiversity.
Generates carbon credits, making large-scale sequestration financially viable.
Avoids land-use conflicts by using non-arable land for algae cultivation.
Advances in genetic engineering and process optimisation for enhanced carbon fixation.
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Case Study no. 2
Cracking the Algae Code for Clean Fuel in the US - Prototype
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Algae biofuels have the potential to provide a sustainable alternative to fossil fuels, but large-scale production remains costly and inefficient. Traditional methods of selecting suitable algae strains often fail when shifting from lab-controlled environments to real-world outdoor ponds, slowing commercialisation. Identifying fast-growing, high-yield algae species that can withstand natural conditions is essential for scaling up biofuel production.
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The Algae DISCOVR Project (Development of Integrated Screening, Cultivar Optimisation and Validation Research) is a collaborative effort aimed at rapidly identifying the most productive algae strains for biofuel production. The project leverages advanced simulation and screening technologies to accelerate the selection process:
✔️ Environmental Algae Pond Simulators (LEAPS) mimic real-world conditions, allowing multiple algae strains to be tested under different light and temperature scenarios.
✔️ Multi-phase screening identifies strains with high growth rates, high oil content, and resistance to bacteria and predators.
✔️ Rapid Evolution Techniques expose algae to controlled stressors to encourage adaptation to outdoor conditions.
✔️ Large-scale outdoor testing validates the most promising strains in Arizona ponds, ensuring real-world viability.
✔️ Biomass assessment modelling predicts algae productivity across different geographic locations to optimise cultivation sites.
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Reduces the cost and time required to identify high-yield biofuel algae strains.
Enables scalable and location-specific algae farming by predicting the best growing conditions.
Supports the transition to renewable biofuels, reducing dependence on fossil fuels.
Provides open-access data and strains to accelerate industry adoption.
Advances sustainable agriculture by integrating algae production with other bioproducts, such as food dyes and protein sources.
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Other interesting cases
Algenie (Australia) – Startup
A biotech company cultivating algae as a low-cost, scalable feedstock for diverse applications—from proteins and plastics to textiles and industrial inputs.
Accordion Photobioreactor (USA) – Prototype
A compact, foldable reactor design offering a cost-effective way to grow algae in controlled environments, ideal for decentralised or small-scale use.
Cyanobacteria Research (UK) – Research
Investigating how blue-green algae can convert carbon dioxide into valuable bio-based materials through natural photosynthesis.
Ethylene from Algae (Finland) – Research
Using engineered cyanobacteria to produce ethylene—an essential industrial chemical—by harnessing solar energy and CO₂ from the air.
The First Algae-Powered Building (Germany) – Prototype
An architectural innovation that integrates algae into building facades to generate heat and energy on-site, showcasing a novel renewable energy model.
Biocompatible Inks from Algae (Germany) – Research
Developing sustainable, algae-derived bio-inks for 3D bioprinting, with potential applications in healthcare and materials science.
Anti-Fouling Photobioreactor Technology (USA) – Prototype
Applying low-voltage currents to photobioreactor walls to prevent biofilm buildup, improving light exposure and system efficiency.
Microalgae Wastewater Treatment (Taiwan) – Review
Evaluating various photobioreactor designs for wastewater treatment, using microalgae to remove pollutants while generating useful biomass.
Future scenarios: what might happen in 2035?
As part of our exploration of these nine underhyped technologies, our partners at Pluriversa conducted a foresight exercise to consider their possible futures and anticipate the challenges and opportunities within. The exercise produced four scenarios for the year 2035, which include speculative use cases for each technology. Here are two potential use cases for Algal Photobioreactors.
2035: Ocean Reoxygenation Plants
Algal photobioreactors are so easy to build that they are part of science programs in school. It is no surprise then that they have become the most common way to clean the air in big urban centres. Most importantly, they have become the main source of oxygen for oceans across the world.
Thanks to a revolutionary bioengineered strain of algae with low methane production, the technology can work at scale and a very low cost. Otherwise, the amount of methane released in the process would have made it unviable.
Although operating the reactors has meant higher taxes, most citizens are glad to pay for them.
2035: Addressing Fuel Shortages
For countries with little or no fuel to run their machines, algae photobioreactors are a practical solution. They can produce biofuel that can replace traditional fossil fuels.
The downside is that this biofuel needs to be properly refined to remove its high level of methane, and not all countries do it. The result has been reduced dependence on fossil fuel imports and at the same time a sharp increase in methane production.
To make things worse, because the technology has the word bio on its name, many people think of the algae biofuel they use as clean. This has created an awareness crisis around the real extent of the problem.
Final thoughts
If you’re working on climate adaptation, biodiversity, agriculture, energy, or urban development, there could be ways to integrate algae-based systems into your work, because the real opportunity lies in applying it creatively, locally, and in combination with other tools already in use.
Some ideas to explore next:
Could a photobioreactor support a circular approach to wastewater treatment or food production?
Might it offer a low-cost, local source of fertiliser or animal feed?
Could carbon credits or bioeconomy markets help make the case for investment?
Are there community partners, universities, or innovators already experimenting with algae?
Algal photobioreactors aren’t a silver bullet—but they offer a rare combination of adaptability, sustainability, and untapped potential. From biofuels to fertiliser, wastewater treatment to carbon capture, this is a technology that could quietly slot into many climate and development strategies—if given the chance.
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An overview of algal photobioreactors for resource recovery from waste
Self-Assembly of Nanofilaments in Cyanobacteria for Protein Co-localization
Printing Green: Microalgae-Based Materials for 3D Printing with Light
Bio-diesel Production as a Promising Approach of Industrial Wastewater Bio-refinery
Role of Extracellular Polymeric Substances in Adsorptive Binding of Heavy Metals
This is a deep dive into one of our nine underhyped frontier technologies for development.
The full exploration will be released on April 23rd. Sign up to the launch event here.