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Where there's a potato, there could be light
By Gilah Kahn-Hoffman
September 20, 2010
In a discovery with far-reaching implications for the developing world, Israeli researchers have created organic 'potato batteries' that can power lights, computers and more.
Cheap, and widely available in most countries of the world all year round, Potatoes make an ideal source of power.
Potatoes offer more than just a valuable source of nutrition, now they can also power your lights and computers, say Israeli researchers.
The scientists from Hebrew University of Jerusalem (HUJ) have discovered that potatoes can be used as organic batteries, providing a cheap, immediate and easy to use source of green power to parts of the world that currently lack electrical infrastructure.
It's a development that could improve the quality of life of 32 percent of the developing non-OECD populations - some 1.8 billion people.
The new organic electric battery can provide the power source to meet significant, low-power needs such as lighting, telecommunication, and information transfer.
"A person with two left hands could do it," Prof. Haim D. Rabinowitch of the university's Faculty of Agriculture, Food and Environment tells ISRAEL21c. "It's like making a sandwich of two metal sheets and a piece of cooked potato in between."
Humble potato is the top choice
Rabinowitch, research student Alex Golberg from the university's School of Computer Science and Engineering, together with Prof. Boris Rubinsky at the University of California at Berkeley, have been studying the electrolytic process in living matter for use in various applications, including the generation of electric energy for self-powered implanted medical electronic devices.
The professor explains that all organic tissue can serve in the construction of such a cell and generate electricity. "It is possible to replace the potato with liver tissue (for example) or any other tissue in our body for self-powered implanted medical electronic devices. Think of a pacemaker that gets its power by contact with the heart tissue or muscles. Such a pacemaker does not require a battery and never stops - as long as the tissue is there."
Practically all organic matter can be used to generate electrical current through electrolysis, but some produce electricity more efficiently than others do. The humble potato was selected for the study because it is widely available almost all year-round, is grown in 130 countries over a wide range of climates (in 2007 alone 325 million tons of potatoes were produced), it isn't messy, stores well for months and is cheap to buy.
In their research, the scientists found a new way to construct an efficient battery using zinc and copper electrodes and a slice of potato. They also discovered that the simple action of boiling a potato prior to use in electrolysis increases electric power up to 10 fold over an untreated potato, and enables the battery to work for days, and even weeks.
Israel's potato battery is freely available to the developing world.
Initially, the researchers believed that the energy stored in the potato tuber (which is 15 to 22% starch) was the main source of power, but they then saw that output was low. Hypothesizing that the resistance of the tissue was reducing the output efficiency, they applied a technique called irreversible electroporation which damages membranes but not a cells' other components or molecules.
Cooking adds power
"It worked like magic," Rabinowitch reports. "Such a device is costly and is not readily available, especially in developing countries, and thus we looked for a simple, cheap, universally-available technology to achieve that goal: Cooking was the answer."
The scientific basis of the finding is related to the reduction in the internal salt bridge resistance of the potato battery, which is exactly how engineers are trying to optimize the performance of conventional batteries. The ability to produce and utilize low power electricity was demonstrated by LEDs powered by treated potato batteries.
Cost analyses showed that the treated potato battery generates energy which is five to 50 fold cheaper than commercially available 1.5 Volt D cells and Energizer E91 cells, respectively. The clean light powered by this green battery is also at least six times more economical than the kerosene lamps often used in the developing world.
Yissum Research Development Company, the technology transfer arm of Hebrew University, has decided to give the invention away free of charge in an effort to help the 1.8 billion people in the developing world not connected to electricity.
Giving to the developing world
Rabinowitch expects that charity funds will take the initiative and start providing economically disadvantaged people with the two sheets of metal and a short piece of electric wire, "so that they can make their own 'potato sandwiches.'"
"The ability to provide electrical power with such simple and natural means could benefit millions of people in the developing world, literally bringing light and telecommunication to their lives in areas currently lacking electrical infrastructure," says Yaacov Michlin, CEO of Yissum.
Interest in the new potato battery is growing. Rabinowitch recently received a letter from an entrepreneur in India interested in community building and environmental solutions. He is hoping to work with the Israeli team to mainstream the concept by creating kits for Indian schoolchildren and their families.