Israeli researchers developed revolutionary way to extract electricity from seaweed

Researchers from the Technion have developed a novel way for harvesting an electrical current straight from seaweed that is both ecologically friendly and efficient.

The idea originated with doctoral student Yaniv Shlosberg while swimming at the beach. He knew that the combustion of fossil fuels produces greenhouse gases and other harmful chemicals, which have been linked to climate change. Pollution begins with the extraction and transportation of fossil fuels to centralized power plants and refineries throughout the world. These perplexing difficulties serve as the impetus for research into alternate, clean, and renewable energy sources.

One of these is the utilization of living organisms as power sources in Microbial Fuel Cells (MFC). Certain bacteria are capable of transferring electrons to electrochemical cells in order to generate electricity. Bacteria require regular feeding, and some are pathogenic.

Bio-PhotoElectrochemical Cells are a comparable technique (BPEC). In the case of the MFC, electrons can be obtained from photosynthetic bacteria, particularly cyanobacteria (also known as blue-green algae). Cyanobacteria synthesize their own sustenance from carbon dioxide, water, and sunlight, and are generally harmless. Indeed, some cyanobacteria, such as Spirulina, are farmed in enormous quantities as “super-foods.”

Profs. Noam Adir Faculty of Chemistry and Schuster’s research groups previously developed methods that exploited cyanobacteria to generate electrical current and hydrogen fuel, which were reported in Nature Communications and Science, respectively. Cyanobacteria do have a few disadvantages. Cyanobacteria generate fewer currents in the dark, as they do not undertake photosynthesis. Additionally, the quantity of current obtained is still less than that obtained using solar cell technology, making the BPEC less commercially appealing.

The researchers from the Technion and from the Israel Oceanographic and Limnological Research Institute (IOLR) tried to solve this issue using a new photosynthetic source for the current – seaweed (macroalgae). Numerous varieties of seaweed grow naturally along Israel’s Mediterranean coast, most notably Ulva (also known as sea lettuce), which is grown in huge quantities for research reasons at IOLR.

Following the development of the new ways for connecting the Ulva and the BPEC, currents 1000 times larger than those produced by cyanobacteria were obtained — currents comparable to those produced by ordinary solar cells.

Prof. Adir says that these higher currents are a result of the high rate of seaweed photosynthesis and the seaweed’s ability to act as the BPEC electrolyte – the solution that facilitates electron transfer in the BPEC.

Additionally, the seaweed provides currents in the dark that are approximately 50% of those obtained in the light.

The dark current is generated during respiration when carbohydrates produced during the photosynthetic process are utilized as an internal source of nutrients.

No extra chemicals are required to generate the current, similar to the cyanobacterial BOEC. Ulva creates electron transfer mediating chemicals, which are secreted from the cells and transfer electrons to the BPEC electrode.

Carbon positive technologies are those that generate energy using fossil fuels. This indicates that the process emits carbon dioxide into the atmosphere during the combustion of the fuel. Solar cell technologies are referred regarded be “carbon-neutral,” as they emit no carbon into the atmosphere.

Solar cell manufacturing and transit to the point of use, on the other hand, are many times more “carbon positive.” The new technology that is being demonstrated here is “carbon negative.” During the day, the seaweed takes carbon from the atmosphere while growing and releasing oxygen. No carbon is released during the daytime collecting of currents. At night, the seaweed respires normally and releases the normal quantity of carbon. Additionally, seaweed, particularly Ulva, is cultivated for a range of businesses, including food (Ulva is often regarded as a superfood), cosmetics, and pharmaceuticals.

“It’s amazing where scientific ideas originate from,” says Yaniv Shlosberg, the graduate student who suggested the use of seaweed. “Archimedes, the famed philosopher, had a bright insight in the bathtub, which resulted in the “Archimedes’ Principle.” I had the thought one day.

The researchers recently published a paper in the journal Biosensors and Bioelectronics describing their novel approach for directly collecting an electrical current from macroalgae (seaweed).

The article summarizes findings from researchers at Schulich Faculty of Chemistry, Biology, Biotechnology, and Food Engineering, GTEP, and IOLR.