Spinach could fuel the next wave of efficient renewable energy, so say researchers from the Technion-Israel Institute of Technology. Tapping into a plant cell that uses sunlight to produce water and electricity may be a new method to convert solar power into usable hydrogen fuel.“The combination of natural (leaves) and artificial (photovoltaic (PV) cell and electronic components), and the need to make these components communicate with each other, are complex engineering challenges that required us to join forces,” said Professor Avner Rothschild from the Department of Material Science and Engineering. “The study is unique in that it combines leading experts from three different faculties: biology, chemistry and materials engineering,” said Rothschild.
The multidisciplinary research team included doctoral students Roy Pinhassi, Dan Kallmann and Gadiel Saper under the guidance of Rothschild, Professor Noam Adir of the Chemistry Department and Professor Gadi Schuster of Biology Department.
Artificial photosynthesis and solar fuel projects are on the rise, but strict regulations on bioreactor operating conditions make it difficult to commercialize the process. Working with a simple membrane extract from spinach leaves, the Haifa researchers invented a bio-photo-electro-chemical (BPEC) cell that produces electricity and hydrogen from water, using sunlight. The discovery holds promise to change biofuel production.
Combining man-made BPEC cells with plant membranes, which naturally absorb sunlight and efficiently convert it into electrons for storable chemical energy, paves the way for new clean technologies from renewable sources.
In order to produce electric current via photosynthesis, the researchers added an iron-based compound to the solution. The iron facilitates transfer of electrons from the spinach-leaf membranes to the electrical circuit, creating an electric current within the cell, which can be channeled to form hydrogen gas. In turn, this energy can be converted into heat and electricity by burning the hydrogen, in the same way hydrocarbon fuels are used.
Combustion of hydrocarbon fuels emits the greenhouse gas carbon dioxide into the atmosphere, but the only byproduct of hydrogen combustion is clean water. This Israeli-innovated cell is a closed cycle that begins with water and ends with water. The researchers believe it could be a clean and sustainable alternative fuel.
“These results demonstrate the promise of combining natural photosynthetic membranes and manmade photovoltaic cells in order to convert solar power into hydrogen fuel,” the researchers wrote in their report.
The study findings were published in the online journal Nature Communications. It was funded by the I-CORE (Israeli Centers of Research Excellence) program of the Council for Higher Education’s Planning and Budgeting Committee, the National Science Foundation, a grant from the United States-Israel Binational Science Foundation and the German-Israeli Project Cooperation Program.
Spinach is a great source of energy for our bodies. Now it seems the nutritious leaves can also provide energy for other purposes.