Michelle ThompsonWhen vast amounts of invasive seaweed began appearing on Caribbean beaches in 2011, locals were baffled.
The once-pristine coastlines were soon overwhelmed by piles of sargassum, a seaweed carried by currents from the Sargasso Sea and linked to climate change. Its rotting stench drove away tourists, creating a crisis for small islands heavily reliant on tourism and struggling with limited resources.
In 2018, Barbados’ Prime Minister Mia Mottley declared the issue a national emergency.
Today, a team of innovative Caribbean scientists and environmentalists aims to transform this challenge into an opportunity by converting the problematic algae into valuable biofuel.
Sargassum has blanketed some of the Caribbean’s most stunning beaches, including this one in Antigua.
The team recently introduced the world’s first vehicle powered by bio-compressed natural gas. Developed at the University of the West Indies (UWI) in Barbados, this innovative fuel is made using wastewater from local rum distilleries and dung from the island’s indigenous blackbelly sheep, which supplies essential anaerobic bacteria.
The team claims that any car can be converted to run on this biofuel through a straightforward, affordable four-hour installation using a readily available kit, at a cost of around $2,500 (£1,940).
Initially, researchers explored using sugarcane as a renewable source to reduce dependence on expensive imported fossil fuels and help the Caribbean move toward its zero-emissions goal. However, despite Barbados being one of the few islands still producing sugarcane, the amount produced was insufficient for the team’s ambitious objectives, according to Dr. Legena Henry, the project’s founder.
Dr. Legena Henry states that there is no shortage of sargassum to fuel cars.
Sargassum, on the other hand, Dr. Legena Henry notes with a grimace, is something “we will never run out of.”
“Tourism has suffered greatly due to the seaweed; hotels have spent millions trying to manage it. It’s created a crisis,” says Dr. Henry, a renewable energy expert and UWI lecturer.
The idea of using it for a beneficial purpose came from one of her students, Brittney McKenzie, who had noticed the large number of trucks hauling sargassum from Barbados’ beaches.
“We had just spent three weeks researching sugarcane, but when I saw Brittney’s excitement, I couldn’t discourage her,” Dr. Henry recalls.
With rum distillery wastewater already available, the team decided to experiment by combining it with sargassum.
Brittney was assigned to gather seaweed from the beaches and set up small-scale bioreactors for initial research.
“Within just two weeks, we had promising results,” Brittney tells the BBC. “It was turning into something far bigger than we initially anticipated.”
The team filed a patent for their formula, and in 2019, they presented the project to potential investors at a side meeting during the UN General Assembly in New York.
Upon returning to Barbados, Dr. Henry’s phone was “buzzing” with messages of congratulations, including one from the US-based Blue Chip Foundation offering $100,000 to help launch the project.
Biologist Shamika Spencer was then hired to experiment with various proportions of sargassum and wastewater to determine the optimal mixture for producing the most biogas.
Shamika Spencer conducted experiments with various ratios of seaweed and wastewater to find the optimal mix for producing the most biogas.
Shamika Spencer eagerly seized the opportunity to participate in the project.
“Sargassum has been affecting the region for years,” explains Ms. Spencer, originally from Antigua and Barbuda. “I had always wondered about this new seaweed ruining the beaches in Antigua, and when I came to Barbados to study, I noticed it here as well.”
The algae pose not only a threat to tourism but also to human health, as they release hydrogen sulfide during decomposition. They also endanger native wildlife, such as critically endangered sea turtle hatchlings, which can become trapped in thick mats of beached seaweed.
Water pollution and warming seas are believed to have caused the rise in sargassum, a catastrophic consequence of climate change that the Caribbean did little to cause but often bears the brunt of. Regional leaders, including Barbados’ Prime Minister Mia Mottley and Antigua’s Prime Minister Gaston Browne, have made loud calls for eco reparations as the Caribbean battles rising sea levels and worsening storms.
While waiting for international support, this project showcases the Caribbean taking control of its environmental future.
Ms. Spencer emphasizes, “After removing sargassum from beaches, it’s important that it doesn’t just end up in landfills. Repurposing it for vehicles helps protect tourism and prevents people from inhaling it. As we scale up to fuel more vehicles, it will require large volumes.”
Dr. Henry smiles as she recalls the exhilarating moment of watching the successful test drive of a biogas-powered Nissan Leaf, supplied by the Caribbean Centre for Renewable Energy and Energy Efficiency.
As a mechanical engineer educated at MIT, Dr. Henry knew she was risking her reputation if the project failed. “We didn’t sleep the night before the test drive event,” she admits. “I was putting my whole life’s work on the line.”
Together with her husband, Nigel Henry, a career data scientist, Dr. Henry co-founded Rum and Sargassum Inc., with the goal of revolutionizing energy production in the Caribbean. Both are originally from oil-producing Trinidad, studied in the US, and were determined to apply their skills back home.
“My goal is to help build up this region,” says Dr. Henry. The team is currently setting up a four-car pilot to demonstrate real-life working prototypes to convince potential investors of its scalability.
The initial commercial activities are projected to cost around $2 million, with $7.5 million needed to expand to a point where they can sell gas to 300 taxis in Barbados. Potential funders include the US Agency for International Development, the European Union, and international development banks through debt financing.
The team plans to grow their work by establishing a larger biogas station and introducing other sargassum-based innovations, like pest control products.
Ms. Spencer reflects on the journey, saying, “Just seeing the actual potential is motivating me to keep working.”
Brittney McKenzie describes seeing her idea come to life as “mind-blowing.”
Five years after her eureka moment, Brittney McKenzie says she’s still “pinching” herself.
“To see the car in action was mind-blowing,” she smiles. “I would encourage all young scientists to pursue their ideas. You never know when you might make the next big discovery.”
Dr. Henry agrees, noting, “It’s taken years of hard work, determination, and overcoming many obstacles to reach this point. This is a prime example of UWI innovation, and it’s something that can be exported globally. It’s not just the Caribbean facing this issue—sargassum also affects parts of West Africa, South America, and Florida.”
“These small islands have developed technology that can benefit the world; this is a major win for the Caribbean,” she adds.
