Can Sargassum Solve the Caribbean’s Energy Crisis?

The Caribbean faces an unprecedented challenge: tons of sargassum seaweed threaten its tourism economy and accelerate the search for innovative energy solutions.

A Growing Environmental and Economic Crisis

In recent weeks, the postcard-perfect image of turquoise waters and white sand across much of the Caribbean has been buried under a brown blanket that, within days, turns into a toxic, foul-smelling mass. Sargassum, a brown seaweed that has proliferated uncontrollably for over a decade, is washing ashore in Mexico, the Dominican Republic, Puerto Rico, Barbados, and other islands, disrupting tourism and degrading coastal ecosystems.

In Playa del Carmen, for example, the most photographed coastline of the Riviera Maya can transform into a dense belt of seaweed up to a meter thick during peak season. The decomposition of this material releases hydrogen sulfide and ammonia, gases responsible for the stench that forces beach closures, evacuations, and even temporary hotel shutdowns.

For residents and tourism operators, this is more than an environmental issue—it’s an economic crisis. Thousands of families depend on these beaches, which become unusable for parts of the year.

"This is the sargassum arriving today in Playa del Carmen, Quintana Roo."
— Alerta Vigilante Tlaxcala-México (@AlertaVigilante) June 27, 2025

The scale of the problem is staggering. According to satellite data from the University of South Florida, in 2024, the Great Atlantic Sargassum Belt exceeded 13 million tons of floating seaweed—a mass so vast it surpasses the surface area of Mexico. While intensity and distribution vary each season, the trend shows sustained growth that threatens to become permanent.

From Problem to Opportunity: Energy from Sargassum

As removal efforts proved insufficient, researchers and governments began exploring ways to repurpose the seaweed. The idea emerged: Could sargassum be converted into energy?

A Waste with Energy Potential

Initial experiments took place in university labs in Mexico and Jamaica, where scientists confirmed that sargassum’s organic matter, despite its high salt and lignin content, could be digested in anaerobic processes. Sealed digesters, which convert organic waste into methane-rich biogas, showed promise if the seaweed was first washed and pre-hydrated to reduce salinity—a key obstacle in bacterial conversion.

Later, other research groups explored pyrolysis, a method that heats biomass in the absence of oxygen to break it down into combustible gases, liquid bio-oil, and charcoal. In the Dominican Republic and Puerto Rico, small pilot plants confirmed that sargassum could be transformed into a moderate-energy gas for adapted electrical generators. However, technical challenges emerged: chlorine and metals in the seaweed accelerate equipment corrosion, and high water content requires costly pre-drying.

Fermentation and Liquid Biofuel Attempts

European projects, in collaboration with Caribbean universities, proposed fermenting sargassum’s carbohydrates to produce ethanol. Enzymatic hydrolysis was used to break down polysaccharides into simple sugars, which could then be converted into combustible alcohols. While lab tests succeeded, low energy density, toxin neutralization costs, and processing expenses kept this approach experimental.

Notable Pilot Projects

Several regional initiatives highlight progress in energy solutions:

• Puerto Morelos, Mexico: A pilot plant combines sargassum with agro-industrial waste (like sugarcane bagasse) to produce biogas, generating electricity for public facilities. However, capacity remains limited compared to daily seaweed influx.
• Guadeloupe and Martinique: EU-funded projects developed mixed solutions—part composting, part thermal processing for heat and electricity. Integrated drying, shredding, and gasification improved energy yields.
• Riviera Maya: Start-ups and hotels partnered to produce dried sargassum pellets burned in adapted boilers for thermal energy. Early results were promising, but scaling up requires sustained public investment.

Economic and Environmental Challenges

Converting sargassum into energy isn’t just a technical hurdle—it’s an economic and regulatory puzzle. Transporting seaweed from beaches to processing plants can account for 60% of operational costs, and handling byproducts (like salt- and metal-laced ash) demands strict protocols.

Despite these obstacles, pressure from the tourism industry and environmental awareness are driving regional efforts to treat sargassum as a strategic resource.

The Need for Structural Change

The crisis has exposed the need for an integrated approach—combining prevention, containment, collection, and repurposing. While barriers and beach excavators have proven inadequate, energy conversion offers a broader opportunity: turning an environmental hazard into a resource that mitigates tourism losses.

Scaling these solutions will require public-private investment, clear waste management regulations, and environmental safeguards. Meanwhile, in Cancún, Punta Cana, and Tulum, workers continue dawn cleanups as sargassum—a silent tide—threatens to permanently alter the Caribbean’s landscape. The urgency to transform this threat into energy grows with each new season.