January 17, 2022

Electricity from the Sea

Pictured Above / Technion researchers have developed a new method that harvests an electrical current directly from seaweed in an environmentally friendly and efficient fashion.

Technion Ph.D. candidate Yaniv Shlosberg was walking on the beach one day when he noticed a rock covered by seaweed that looked like electrical cords. He had been researching a type of bacteria that obtained energy through photosynthesis and thought that maybe this sun-loving seaweed could also produce electrical currents.

Using that common seaweed, called Ulva, as a source of energy, Shlosberg and a team of researchers from the Technion and the Israel Oceanographic and Limnological Research Institute have succeeded in developing an ecologically friendly, energy efficient method of harvesting electrical currents on par with standard solar cells and more powerful than other sustainable techniques.

This is one of the seaweed (Ulva) growth vats at in Haifa, Israel.

To combat climate change, scientists have long been experimenting with blue-green algae known as cyanobacteria and other living organisms as an alternative to burning fossil fuels to produce electricity. But results have been underwhelming. Ulva, on the other hand, produces electrical currents 1,000 times greater than cyanobacteria and can even provide current in the dark. And while solar cell technologies are “carbon neutral,” the seaweed absorbs carbon from the atmosphere while growing and releasing oxygen, making the new technology “carbon negative.”

Shlosberg and his mentor Professor Noam Adir attribute Ulva’s success to its ability to convert sunlight into chemical energy with a high rate of photosynthetic efficiency and to facilitate electron transfer.

The researchers built a prototype device that collects the current directly in an Ulva growth vat, clearly demonstrating that significant currents can be harvested from the seaweed. “We believe that the technology can be further improved leading to future green energy technologies,” said Prof. Adir of the Shulich Faculty of Chemistry and the Nancy and Stephen Grand Technion Energy Program.

“The famous philosopher Archimedes had a brilliant idea in the bathtub leading to the Archimedes’ Principle,” Shlosberg said. “I had my idea one day when I went to the beach.”