Doctoral student Yaniv Shlosberg, along with a consortium of researchers from three Technion Faculties, and a researcher from the Israel Oceanographic and Limnological Research Institute, have developed a new method that harvests an electrical current directly from seaweed in an environmentally friendly and efficient fashion.

The cleaner, the better

The use of fossil fuels results in the emission of greenhouse gases and other polluting compounds that are connected to climate change. Fossil fuel-based energy-producing technologies are known as “carbon positive” which means that the fuel combustion process releases carbon into the atmosphere. So not only is their use toxic but extracting and transporting them around the world is also highly pollutant. Essentially, they are toxic at all stages of their lifecycle. As the climate crisis continues to be at the forefront of global concerns, more and more research is being done into methods of alternative, clean, and renewable energy sources.

One of the methods being explored in alternative energy sources is using living organisms as the source of electrical currents in microbial fuel cells (MFC). Certain bacteria can transfer electrons to electrochemical cells to produce electrical current. The source of electrons can be from photosynthetic bacteria, especially cyanobacteria (also known as blue-green algae). Cyanobacteria make their own food from carbon dioxide, water, and sunlight. Since there are some drawbacks in using cyanobacteria, like the fact that it produces fewer currents in the dark and that the amount of current obtained is still less than that obtained from solar cell technologies, researchers have set out to discover different methods, in hopes of mitigating some of these to mitigate these deficiencies.

Essentially, the researchers at the Technion are trying to use a new photosynthetic source for the electric current – seaweed (macroalgae) – which has many different species types that grow naturally on the Mediterranean shore of Israel. The researchers successfully used Ulva, a type of seaweed found in abundance here in Israel and were able to obtain from it currents 1000 times greater than those from cyanobacteria, which puts it on the same level as those obtained from standard solar cells. Not only is this new technology producing the same levels in standard solar cells, but it is better for the environment. How? Solar cell technologies are known as “carbon-neutral” because no carbon is released into the atmosphere for their use. However, the production of solar cells and their transportation to the site of use can turn this technology into being “carbon positive”. Yet the new technology presented by the Technion's new research is actually “carbon negative” because the seaweed absorbs carbon from the atmosphere while releasing oxygen.

“It is a wonder where scientific ideas come from,” says Yaniv Shlosberg, the graduate student who first thought of the possibility of using seaweed. “The famous philosopher Archimedes had a brilliant idea in the bathtub, leading to the “Archimedes’ Principle”. I had the idea one day when I went to the beach and noticed seaweed on a rock that looked like electrical cords. I said to myself – since they also perform photosynthesis, maybe we can use them to produce currents”. The rest is history. Here’s hoping that their research can lead to a real revolution in clean energy production, and help our planet get on the right track.

The researchers have already presented their new method for collecting an electrical current directly from macroalgae (seaweed) in the journal Biosensors and Bioelectronics. The research was led by Prof. Noam Adir and the doctoral student Yaniv Shlosberg, from the Schulich Faculty of Chemistry and GTEP. They collaborated with additional researchers from the Technion: Dr. Tunde Toth (Schulich Faculty of Chemistry), Prof. Gadi Schuster, Dr. David Meiri, Nimrod Krupnik and Benjamin Eichenbaum (Faculty of Biology), Dr. Omer Yehezkeli and Matan Meirovich (Faculty of Biotechnology and Food Engineering) and Dr. Alvaro Israel from IOLR in Haifa.

The articles featured photo shows one of the seaweed (Ulva) growth vats at the Israel Oceanographic and Limnological Research Institute (IOLR) in Haifa. The vat is near the beach, and fresh seawater continuously flows through the system. Inside the vat the researchers have introduced the electrochemical system. As the Ulva move in the vat, they associate with an electrode, producing a light-dependent electrical current that is measured by the external computer-operated potentiostat.