“Barbados has committed to becoming fossil-fuel-free by 2030, but that will probably cause huge economic damage because not a lot of people here can afford an electric car. Brazil solved this problem with cars fuelled by sugar-cane biodiesel, but there’s not enough sugar cane grown here to copy that approach. One of my undergraduate students, Brittney McKenzie, saw a possible solution. There is a sargassum seaweed crisis in Barbados. One tourist resort was spending US$2 million every year to remove it from the resort beach. McKenzie asked, what if we use sargassum to make biofuel?
She tested it in the laboratory, and it worked so well that it shifted my whole research trajectory. In this photo, I’m collecting sargassum to put into a digester, along with rum distillery waste water. Under anaerobic conditions, the microbes in the mix, feeding on the sugar in the waste water, digest the sargassum and produce gaseous methane biofuel. All the islands in this region of the Caribbean have a sargassum problem and a rum wastewater problem — and ultimately a climate-change problem. This solution is a win–win–win.
We estimate that, if we converted 100,000 fossil-fuel-powered vehicles in Barbados — around 75% — to run on our biofuel, it would remove 17 million tonnes of carbon emissions from the atmosphere over the average vehicle lifetime of 14 years. It would also halve the cost of vehicle fuel for people in Barbados.
In 2021, my colleagues and I co-founded a start-up company, Rum & Sargassum, and now the first challenge is to find ways to scale this up to meet our initial target of 2,000 customers here. Then, we must convince investors that this is a scalable solution for renewable energy.”
This interview has been edited for length and clarity.
