In 2011, vast amounts of invasive seaweed began washing up on Caribbean beaches, leaving local residents puzzled.

Soon, unsightly sargassum carpets overwhelmed the pristine coastlines, deterring tourists with the foul smell it emitted as it decomposed. The situation presented a daunting challenge for small, tourism-dependent islands with limited resources.

Barbados’ Prime Minister Mia Mottley declared a national emergency in 2018 to address the crisis.

Now, a groundbreaking team of Caribbean scientists and environmentalists is tackling the issue innovatively, transforming the problematic seaweed into biofuel. This effort led to the launch of one of the world’s first vehicles powered by bio-compressed natural gas.

Developed at the University of the West Indies (UWI) in Barbados, the fuel blends sargassum, wastewater from local rum distilleries, and dung from indigenous blackbelly sheep, which provides crucial anaerobic bacteria.

The team emphasises that any vehicle can be converted to run on this gas using a simple, affordable four-hour installation process costing approximately $2,500 (£1,940).

Initially, researchers considered sugarcane as a potential biofuel source. However, while Barbados still produces sugarcane, the supply was insufficient for their ambitious goals.

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 of repurposing sargassum originated with Brittney McKenzie, a student at UWI. Observing the extensive use of trucks to clear seaweed from Barbados’ beaches, she proposed exploring its potential as biofuel.

“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.”

McKenzie collected samples and conducted preliminary research using small-scale bioreactors.

“Within just two weeks we got pretty good results,” Brittney said. “It was turning into something even bigger than we initially thought.”

The team subsequently patented their formula and presented their findings at the 2019 UN General Assembly in New York. Their efforts attracted attention, including a $100,000 grant from the US-based Blue Chip Foundation.

Biologist Shamika Spencer joined the project to refine the process, experimenting with different ratios of sargassum and wastewater to optimise biogas production.

Spencer relished the opportunity.

“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 initiative addressed multiple environmental threats: sargassum’s harmful hydrogen sulphide emissions, its impact on endangered wildlife like sea turtle hatchlings, and the broader repercussions of climate change, such as rising sea levels and worsening storms.

While Caribbean leaders, including Mottley and Antigua’s Prime Minister Gaston Browne, have called for eco-reparations, this project represents a proactive step toward environmental resilience.

“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.”

The successful test drive of a biogas-powered Nissan Leaf, supplied by the Caribbean Centre for Renewable Energy and Energy Efficiency, was a thrilling milestone, said project founder Dr. Legena Henry, a mechanical engineer educated at MIT.

“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, data scientist Nigel Henry, established the deep-tech company Rum and Sargassum Inc., aiming to revolutionise energy production in the Caribbean. Both are originally from Trinidad, a leading oil producer, and returned to the region after studying in the United States to apply their expertise locally.

“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.”

Dr. Henry estimates it will cost $2 million to launch initial commercial activity and $7.5 million to scale production for supplying gas to 300 taxis in Barbados. Potential funding sources include the U.S. Agency for International Development, the European Union, and international development banks.

The team envisions building a dedicated biogas station to replace their current small facility and expanding into other sargassum-based innovations, such as pest control products. UWI also plans to explore additional applications for the algae.

Spencer describes witnessing the team’s progress as “heartwarming,” while McKenzie, five years after her breakthrough idea, says she still finds it hard to believe how far they’ve come.

This initiative demonstrates how innovative thinking can turn environmental challenges into opportunities, offering a sustainable solution for the Caribbean while advancing global energy alternatives.

“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.”

 

——————————————————————————

At Natural World Fund, we are passionate about rewilding the UK to stop the decline in our wildlife.

Donate now and join in the solution!