Caribbean Initiative Transforms Problematic Seaweed into Vehicle Fuel

When extensive amounts of invasive seaweed began appearing on Caribbean beaches in 2011, local inhabitants were bewildered. Soon, masses of unsightly sargassum – transported by currents from the Sargasso Sea and associated with climate change – covered the region’s cherished coastlines, deterring tourists with the strong odor it released as it decayed. Determining how to address this presented an unprecedented challenge for the 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 aims to reverse this situation by converting the troublesome algae into a profitable biofuel. They recently unveiled one of the world’s first vehicles powered by bio-compressed natural gas. This innovative fuel source, developed at the University of the West Indies (UWI) in Barbados, also incorporates wastewater from local rum distilleries and dung from the island’s indigenous blackbelly sheep, which supplies essential anaerobic bacteria. The team states that any car can be converted to run on this gas through a straightforward and affordable four-hour installation process, using a readily available kit, at an approximate total cost of $2,500 (£1,940). Researchers had initially investigated using sugarcane to lessen reliance on expensive, imported fossil fuels and guide the Caribbean toward its ultimate goal of zero emissions. However, despite Barbados being one of the few islands still producing sugarcane, the quantity was deemed insufficient for the team’s ambitious objectives, as explained by the project’s founder, Dr. Legena Henry. Sargassum, on the other hand, she grimaces, is something “we will never run out of”. “Tourism has suffered a lot from the seaweed; hotels have been spending millions on tackling it. It’s caused a crisis,” Dr. Henry, a renewable energy expert and UWI lecturer, continues. The idea that it could serve a valuable purpose was proposed by one of her students, Brittney McKenzie, who had observed the large number of trucks used to transport sargassum from Barbados’ beaches. “We’d just spent three weeks researching sugarcane. But I looked at Brittney’s face and she was so excited, I couldn’t break her heart,” Dr. Henry recalls. “We already had rum distillery waste water so we decided to put that with sargassum and see what happened.” Brittney was assigned the task of collecting seaweed from beaches and establishing small-scale bioreactors to conduct preliminary research. “Within just two weeks we got pretty good results,” Brittney tells 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 during a side meeting at the UN General Assembly in New York. Upon returning to Barbados, Dr. Henry’s phone was “buzzing” with congratulatory messages – including one from the US non-profit Blue Chip Foundation offering $100,000 to commence the work. Biologist Shamika Spencer was hired to experiment with varying amounts of sargassum and wastewater to determine which combination yielded the most biogas. She says she eagerly embraced the opportunity to participate. “Sargassum has been plaguing the region for several years,” Ms. Spencer, who is from Antigua and Barbuda, explains. “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 too.” The algae not only threaten tourism but also pose a risk to human health through the hydrogen sulphide released during decomposition, as well as to native wildlife like critically endangered sea turtle hatchlings that become trapped in thick mats of beached seaweed. Water pollution and warming seas are credited with the increase in sargassum, another catastrophic outcome of climate change that the Caribbean has contributed little to but often bears the brunt of. Calls for eco reparations from leaders including Barbados’ leader Mia Mottley and Antigua’s Prime Minister Gaston Browne have been vocal in recent years as the region confronts continuously rising sea levels and intensifying storms. While awaiting these efforts to materialize, this project exemplifies the Caribbean taking charge of its environmental future. “I realised it was important that after removing the sargassum from beaches, it doesn’t just go to landfills,” Ms. Spencer continues. “By repurposing it in vehicles you protect tourism and prevent people from inhaling it. When we scale up to fuel more vehicles it will require a very large volume.” Watching the successful test drive of a biogas-charged Nissan Leaf – supplied by the Caribbean Centre for Renewable Energy and Energy Efficiency – was utterly exhilarating, smiles Dr. Henry. The MIT-educated mechanical engineer knew she was risking her reputation should the venture fail. “We didn’t sleep the night before the test drive event,” she admits. “I was putting my whole life’s work on the line.” Dr. Henry and her husband, career data scientist Nigel Henry, established the deep tech firm Rum and Sargassum Inc and are committed to transforming energy production in the Caribbean. Both are originally from Trinidad, a leading oil producer, studied in the US, and were determined to bring their skills back home. “My goal is to help build up this region,” Dr. Henry says. “We are now setting up a four-car pilot to demonstrate real life working prototypes to convince funders that this is workable and scalable.” She estimates that approximately $2 million will be needed to showcase initial commercial activity and $7.5 million to reach the stage where the company 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 expand its operations by constructing a biogas station to replace its small existing facility. UWI also hopes to introduce other sargassum-based innovations, such as pest control products. Ms. Spencer says it’s been “heart-warming” to witness the results of the team’s research. “Just seeing the actual potential is motivating me to keep working,” she adds. As for Brittney, five years after her eureka moment, she says she’s still “pinching” herself. “To see the car in action was mind-blowing,” she grins. “I would encourage all young scientists to press ahead with their ideas. You never know when you might make the next big discovery.” “It’s taken years of work, plenty of grit and pushing against walls to reach this point,” Dr. Henry concurs. “It’s an example of UWI innovation and is exportable to the wider world, because it’s not just the Caribbean that’s affected; sargassum also impacts 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 big win for the Caribbean.” Copyright 2024 BBC. All rights reserved. The BBC is not responsible for the content of external sites. Read about our approach to external linking.