How smelly seaweed could soon power cars

When large areas of invasive seaweed began washing up on Caribbean beaches in 2011, locals were baffled.

Soon, unsightly piles of sargassum — carried by currents from the Sargasso Sea and linked to climate change — were covering the region’s precious coastlines, repelling vacationers with the stench emanating as they rotted.

How to deal with this particular problem has been 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 scientists and environmental activists in the Caribbean hopes to turn this problem around by turning pesky algae into profitable biofuel.

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 dung of black-bellied black sheep indigenous to the island which provides vital anaerobic bacteria.

The team says any car can be converted to run on gas with a simple and affordable four-hour installation process, using a readily available kit, for a total cost of around $2,500 (£1,940).

The researchers had initially looked into using sugarcane to reduce reliance on expensive imported fossil fuels and help guide the Caribbean region towards its ultimate goal of reducing emissions to zero.

However, despite Barbados being one of the few islands still producing sugarcane, the quantity was deemed insufficient to meet the team’s ambitious goals, explains project founder Dr. Ligina Henry.

On the other hand, she says with a frown, Sargassum is something she “will never run out of.”

Tourism has suffered greatly from seaweed; Hotels spend millions treating them. “This has caused a crisis,” continues Dr. Henry, a renewable energy expert and lecturer at the University of Wisconsin.

The idea that it could have a valuable purpose was suggested by one of her students, Brittney McKenzie, who noticed the volume of trucks being deployed to transport sargassum from the beaches of Barbados.

“We had just spent three weeks searching for 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 waste water to distill rum, so we decided to put it with sargassum and see what would happen.”

Britney was tasked with collecting seaweed from beaches and creating small-scale bioreactors to conduct primary research.

“In just two weeks we had very good results,” Britney told the BBC. “It’s turned into something bigger than we initially thought.”

The team filed a patent for its formula, and in 2019, presented its project to potential investors during a side meeting at the United Nations General Assembly in New York.

As the plane landed in Barbados, Dr. Henry’s phone was “buzzing” with congratulatory messages – including one from the US non-profit Blue Chip Foundation offering $100,000 to start the business.

Biologist Shamika Spencer was assigned to conduct experiments with different amounts of sargassum and wastewater to see which combination produced the most biogas.

She says she jumped at the opportunity to participate.

“The Sargassum region has been plagued for several years,” explains Ms. Spencer, who is from Antigua and Barbuda. “I’ve always wondered about this new seaweed ruining the beaches in 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 through the hydrogen sulfide they release as they decompose, along with local wildlife such as endangered sea turtle hatchlings that become trapped in thick mats of seaweed on the beach.

Water pollution and warming seas are credited with the rise of sargassum, another catastrophic consequence of climate change to which the Caribbean has done little to contribute but often bears the brunt.

Calls for environmental reparations from leaders, including Barbados Leader Mia Mottley and Antigua Prime Minister Gaston Browne, have been loud in recent years as the region battles persistently rising sea levels and worsening storms.

Waiting for these projects to come to fruition, this project represents one example of the Caribbean taking its environmental future into its own hands.

“I realized that it was important that once the sargassum was removed from the beaches, it didn’t just go into landfills,” Ms. Spencer continues.

“By reusing it in vehicles, you protect tourism and prevent people from breathing it in. As we expand to fuel more vehicles, it will require very large quantities.

Dr. Henry smiled, saying: “Watching the successful test drive of the biogas-charged Nissan LEAF – provided by the Caribbean Center for Renewable Energy and Energy Efficiency – was very exhilarating.”

The MIT-educated mechanical engineer 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.”

Dr. Henry and her husband, professional data scientist Nigel Henry, founded the deep technology company Rum and Sargassum Inc, and are on a mission to change the face of energy production in the Caribbean.

Both originally from leading oil producing country Trinidad, they had studied in the US and were determined to bring their skills back to their home country.

“My goal is to help build this area up,” says Dr. Henry. “We are now preparing a four-car pilot to demonstrate real prototypes to convince financiers that this is viable and scalable.”

She estimates the initial business proposition will cost between $2 million and $7.5 million to get to the point where the company is able to sell gas to 300 taxis in Barbados.

Potential financiers 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 establishing a biogas plant to replace its current small facility.

The University of Wisconsin hopes to introduce other sargassum-based innovations as well, such as pest control products.

Ms Spencer says it was “heart-warming” to see the results of the team’s research.

“Just seeing the actual potential motivates me to keep working,” she adds.

As for Britney, five years after her eureka moment, she says she’s still “pushing” herself.

“Seeing the car running was amazing,” she smiles. “I would encourage all young scientists to move forward with their ideas. You never know when you might be able to make the next big discovery.

Dr. Henry agrees: “It has taken years of work and a lot of determination and pressure to get to this point.” “It’s an example of UW’s innovation, and it’s exportable to the wider world, because it’s not just the Caribbean that’s affected; sargassum is also affecting 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.