From nuisance to naches: Caribbean scientists turn invasive seaweed into biofuel

The innovative project, born out of necessity and creativity, seeks to leverage available resources while addressing the ongoing environmental consequences tied to climate change.

The Caribbean has long grappled with the growing issue of sargassum, an invasive seaweed that began inundating the region's coastlines in 2011. Initially viewed as a perplexing eyesore that detracted from the area's appeal, it has since come to symbolize the environmental challenges facing small islands. The rotting vegetation, now associated with climate change and flooding beaches, prompted Barbados’ Prime Minister Mia Mottley to declare a national emergency in 2018 due to the seaweed's impact on tourism and natural ecosystems.

However, a group of determined scientists from the University of the West Indies (UWI) have taken a bold step to turn this dilemma into an opportunity. They recently achieved a milestone by launching the world’s first vehicle powered by bio-compressed natural gas derived from sargassum. This innovative fuel solution also incorporates wastewater from local rum distilleries and organic waste from indigenous blackbelly sheep, fostering a renewable cycle of energy production.

The transformative process requires simple modifications to existing vehicles that can be completed in just four hours and at an estimated cost of around $2,500 (£1,940) to install. Initially, researchers had considered sugarcane as a potential biofuel source to reduce reliance on expensive fossil fuels; however, the limited availability of sugarcane led them to explore the abundant sargassum.

Dr. Legena Henry, a renewable energy expert and UWI faculty member, noted that the use of sargassum emerged from an unexpected idea shared by her student, Brittney McKenzie. During their research on sugarcane, McKenzie had identified the massive volume of sargassum being transported off the beaches by trucks, leading to the innovative combination of the seaweed with distillery wastewater. The experimentation yielded immediate positive results in biogas production.

By 2019, the research team had filed a patent for their formula and presented their findings to investors during a UN General Assembly side meeting. The project garnered attention and financial backing, including a $100,000 investment from the US-based Blue Chip Foundation.

Biologist Shamika Spencer joined the effort, experimenting with varying proportions of sargassum and wastewater to optimize biogas output. She expressed enthusiasm about tackling the sargassum problem, emphasizing its detrimental impact on local tourism and public health due to its decomposing effects. The project not only seeks to mitigate the seaweed crisis but also addresses wider issues posed by climate change, which continues to threaten the Caribbean.

The collaborative force behind this initiative aims to demonstrate that environmental challenges can be met with innovation, thus showcasing Caribbean ingenuity to the world. This pilot project intends to reach broader markets, aiming to power 300 taxis with sustainable energy, with further aspirations to expand to global markets affected by sargassum.

As the team continues their efforts, Dr. Henry called the prototype’s successful test drive—a biogas-charged Nissan Leaf—"exhilarating." Both she and her husband are dedicated to utilizing their education and experience to improve the energy landscape in the Caribbean.

For young scientists like Brittney, witnessing her idea come to fruition has been a revelatory journey, inspiring her to encourage others to pursue innovative solutions. With years of research and persistence paving the way, the project stands as a beacon of hope for the Caribbean—a testament to how even troublesome waste can transform into a green energy asset.