THE ISRAELI POTATO BATTERY

Potato battery could help meet rural energy needs
James Dacey, 26 June 2010 (SciDev)

"The holy grail of renewable energy research may lie in the cooking pot…The search for a cheap source of electricity for remote, off-grid communities, has led to batteries that work on freshly boiled potatoes.

"One slice of potato can generate 20 hours of light, and several slices could provide enough energy to power simple medical equipment and even a low-power computer, said a research team from the Hebrew University of Jerusalem, Israel…The team…said its work hinges on a recent discovery that the electrical flow from potatoes — long known to be natural electrolytes — can be enhanced tenfold when their cell membranes are deliberately ruptured by boiling."

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"To demonstrate, the researchers created a series of batteries out of slices of boiled Desiree potatoes about the size of a standard mobile phone, though they say the type and size of potato slice do not determine its power.

"The device had the same basic components as conventional batteries, consisting of two electrodes separated by an electrolyte (the potato). Each battery powered a small light for 20 hours, after which a new slice could be inserted."

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"Potato batteries are estimated to generate energy at a cost of approximately US$9 per kilowatt hour (kW/h), which compares favourably with the best performing 1.5 volt (AA) alkaline cells — or D cells — which generate energy at US$50/kWh.

"Banana and strawberry batteries could also be used, said [one of the researchers], but their softer tissues would weaken the structure of the battery and the sugars could attract insects…[Concerns include] the limited amount of power that individual batteries can generate and the possible implications of diverting a food crop into energy production."