BBC
Biologist Shanika Spencer was delighted when a test using sargassum to fuel a car was successful
When large areas of invasive seaweed began washing up on Caribbean beaches in 2011, local residents were perplexed.
Soon, mounds of unsightly sargassum – carried by currents from the Sargasso Sea and linked to climate change – covered the region's popular coastlines, repelling vacationers with the acrid stench emitted as it rotted.
Precisely how to resolve this problem was a dilemma of unprecedented proportions for small, tourism-dependent islands with limited resources.
In 2018, Barbados Prime Minister Mia Mottley declared sargassum a national emergency.
Now a pioneering group of Caribbean scientists and environmentalists hope to reverse the trend by turning the troublesome algae into a lucrative biofuel.
Rufus Gobat
Sargassum covers some of the most beautiful beaches in the Caribbean, such as Antigua.
They recently launched the world's first vehicle powered by biocompressed natural gas. The innovative fuel source created at the University of the West Indies (UWI) in Barbados also uses wastewater from local rum distilleries and the droppings of the island's native black-bellied sheep, which provides the vital anaerobic bacteria.
The team says any car can be converted to run on gas via a simple and affordable four-hour installation process, using a readily available kit, at a total cost of around 2,500 $ (£1,940).
Researchers had initially investigated the possibility of using sugarcane to reduce dependence on expensive imported fossil fuels and help the Caribbean reach its ultimate goal of zero emissions.
However, although Barbados is one of the few islands still producing sugarcane, the quantity was deemed insufficient for the team's ambitious goals, says project founder Dr Legena Henry.
Dr. Legena Henry says there is no shortage of sargassum to fuel cars
On the other hand, sargassum, she grimaces, is something “we will never run out of”.
“Tourism has suffered greatly from algae; hotels have spent millions to fix it. This has caused a crisis,” continues Dr Henry, a renewable energy expert and lecturer at the UWI.
The idea that this might serve a useful purpose was suggested by one of his students, Brittney McKenzie, who had observed the volume of trucks deployed to transport sargassum from the beaches of Barbados.
“We had just spent three weeks researching sugar cane. But I looked at Brittney’s face and she was so excited I couldn’t break her heart,” Dr. Henry recalled.
“We already had rum distillery wastewater, so we decided to put it with sargassum and see what happened.”
Brittney was tasked with collecting seaweed from beaches and setting up small-scale bioreactors to conduct preliminary research.
“In just two weeks we've had some really good results,” Brittney told the BBC. “It was turning into something even bigger than we initially thought.”
The team filed a patent on their formula and, in 2019, presented their project to potential investors at a side meeting at the United Nations General Assembly in New York.
When he returned to Barbados, Dr Henry's phone was “buzzing” with congratulatory messages, including one from the Blue Chip Foundation, a US non-profit organization, offering $100,000 to kick-start the work.
Biologist Shamika Spencer was hired to experiment with different amounts of sargassum and wastewater to determine which combination produced the most biogas.
Shamika Spencer experimented with different ratios of algae and wastewater
She says she jumped at the chance to participate.
“Sargassum has been ravaging the area for several years,” says Ms Spencer, originally from Antigua and Barbuda. “I had always wondered about this new algae that was destroying the beaches of Antigua, and when I came to Barbados to study, I noticed it here too.”
Algae doesn't just threaten tourism. They also pose a threat to human health due to the hydrogen sulfide they release as they decompose, as well as to native wildlife, such as critically endangered sea turtle hatchlings, which find themselves trapped in thick mats of stranded algae.
Water pollution and warming seas are responsible for the resurgence of sargassum, another cataclysmic result of climate change to which the Caribbean did not contribute, but of which it is often the first victim.
Calls for green reparations from leaders including Barbados leader Mia Mottley and Antigua Prime Minister Gaston Browne have been resounding in recent years as the region struggles with steadily rising water levels. of the sea and the worsening of storms.
Until these bear fruit, this project represents an example of how the Caribbean is taking charge of its environmental future.
“I realized it was important that after removing sargassum from the beaches, it didn't just go to landfills,” Spencer continues.
“By reusing it in vehicles, you protect tourism and stop people from inhaling it. When we increase our capacity to power more vehicles, it will require very significant volume. »
Watching the successful test drive of a biogas-charged Nissan Leaf – supplied by the Caribbean Center for Renewable Energy and Energy Efficiency – was absolutely exhilarating, smiled Dr Henry.
This MIT-trained mechanical engineer knew she was risking her reputation if her project failed.
“We didn't sleep the night before the test drive,” she admits. “I was putting my life’s work on the line.”
Dr. Henry and her husband, career data scientist Nigel Henry, created deep tech company Rum and Sargassum Inc and are on a mission to change the face of energy production in the Caribbean.
Both hail from Trinidad's major oil producer, studied in the United States and were determined to bring their skills back home.
“My goal is to contribute to the development of this region,” says Dr. Henry. “We are currently setting up a four-car pilot to demonstrate real working prototypes to convince backers that this is feasible and scalable.”
She estimates it will cost around $2 million to show initial commercial activity and $7.5 million to reach the point where the company will be able to sell gas to 300 taxis in Barbados.
Potential lenders include the United States Agency for International Development, the European Union and international development banks through debt financing.
The team plans to expand its work by installing a biogas station to replace its existing small installation.
The UWI also hopes to introduce other sargassum-based innovations, such as pest control products.
Spencer said it was “heartwarming” to see the team’s research results.
“Just seeing the real potential motivates me to keep working,” she adds.
Tremaine year wood
Brittney McKenzie says seeing her idea put into practice was “mind-blowing”
As for Brittney, five years after her eureka moment, she says she's still “pinching” herself.
“Seeing the car in action was breathtaking,” she smiles. “I encourage all young scientists to pursue their ideas. You never know when you'll make the next big discovery.
“It took years of work, a lot of courage and pressure to get to this point,” admits Dr. Henry. “This is an example of UWI innovation and it is exportable around the world, because it is not just the Caribbean that is affected; Sargassum also affects parts of West Africa, South America and Florida.
“These small islands have created technology that can benefit the rest of the world; this is a great victory for the Caribbean.
