Researchers have developed a biological fuel cell that uses tomato waste to generate electricity.
If we had to name a food with electrical virtues, there’s no doubt but that the humble potato would top the list. However, in terms of electricity production, tomatoes are not far behind. It's the latest idea presented by a group of American researchers at the annual meeting of the American Chemical Society in March 2016.
Rotting tomato, polluting tomato
Behind the project was the determination to find a solution to the problem of all the tomato waste. In Florida, where the scientists conducted their experiments, 396,000 tonnes of tomato waste is produced every year. But when it decomposes, methane - a powerful greenhouse gas with a far greater global warming effect than CO2 - is released.
A biological fuel cell
Researchers therefore developed a biological fuel cell, which works with bacteria. The aim is to make use of tomato waste and generate electricity.
The electric current in the fuel cell is generated by an oxidation process. The process is triggered when the bacteria and tomato waste come into contact. Oxidation then emits electrons which are captured by the fuel cell, thereby generating electricity.
The scientists had an unexpected but pleasant surprise! The lycopene in tomatoes - the pigment that gives them their red color - serves as a natural mediator and so makes it possible to transfer the electrons produced by the oxidation to the battery’s electrode. A fortuitous discovery since the mediators usually employed tend to be toxic.
At the moment the device produces 0.3 W of electricity with 10 mg of waste. The result is modest, but it still has great promise for energy transition.
Especially since scientists think that if they were to perfect their process, they would soon be able to produce the equivalent of 90 days of electricity per year for the Walt Disney World theme park – just with the tomato waste produced in Florida!
And on a global scale that’s what dreams are made of...
Main picture: Getty Images