Potatoes are the most versatile vegetable. You could enjoy them mashed, boiled, roasted, fried, or smashed. But one researcher decided to have his “powered up.” Haim Rabinowitch, based at the Hebrew University of Jerusalem, and his team experimented with boiled potatoes to make off-the-grid energy. According to his research, hooking up the vegetable to metal plates, wires, and light bulbs could light up remote areas all over the world.
How to Make a Battery Out of Boiled Potatoes
As ridiculous as this premise is, the team proved that there is a way for potatoes to conduct energy. “A single potato can power enough LED lamps for a room for 40 days,” claims Rabinowitch. [1]
This experiment is common in high school science classes to show how batteries work. Meanwhile, Rabinowitch and his colleagues discovered that potatoes could become a more viable option for power than once thought.
To make a homemade battery, you need:
- One anode, the negative electrode (like zinc)
- One cathode, the positive electrode (like copper)
- One potato
Keep in mind that the spud doesn’t generate energy. Rather, the acid in the potato creates a chemical reaction between the anode and cathode. When the electrons connect through the potato, they release energy.
Using strange objects as a conductor began in 1780 by Luigi Galvani. When he bonded two metals to frog legs, the muscles began to twitch. But you don’t need a frog; many materials could get that same effect. For instance, Alexander Volta, a contemporary of Galvani, used saltwater-soaked paper with similar results. Others have used a bucket of ocean water or a pile of dirt between the two metal plates.
Cheap Alternative Energy
Despite being a mainstay in high school, potatoes have never been scientifically studied as a power source. So, in 2010, Rabinowitch accepted that challenge himself. He teamed up with Boris Rubinsky of the University of California, Berkeley, and Alex Goldberg, a Ph.D. student.
“We looked at 20 different types of potatoes,” explains Goldberg, “and we looked at their internal resistance, which allows us to understand how much energy was lost by heat.”
When they boiled potatoes for eight minutes, the organic tissues broke down and reduced the resistance between the electrons. This creates more energy. Additionally, they increased the power by slicing the potato and sandwiching each piece with metal plates.
“We found we could improve the output 10 times, which made it interesting economically, because the cost of energy drops down,” says Goldberg.
“It’s low voltage energy,” says Rabinowitch, “but enough to construct a battery that could charge mobile phones or laptops in places where there is no grid, no power connection.”
The research team claimed this potato method is about six times cheaper than the common kerosene lamps. Additionally, they claimed it could cost $9 per kilowatt-hour instead of the typical battery equivalent which can cost about $49–84 per kilowatt-hour. Not only that, but potatoes are cheap and stored easily.
Why Aren’t Potato Batteries Popular?
“We thought organizations would be interested,” says Rabinowitch. “We thought politicians in India would give them out with their names inscribed on them. They cost less than a dollar.”
However, years pass since the original experiment, and still, 1.2 billion people in the world lack access to electricity. So why haven’t leaders and companies turned to the simple potato battery?
“The simple answer is they don’t even know about it,” reasons Rabinowitch.
Still, there is also a longer, more complicated answer.
First off, using food to generate energy poses a problem. According to Olivier Dubois, senior natural resources officer at the United Nations Food and Agriculture Organisation (FAO), this sort of energy could potentially deplete food supply and compete with farmers who grow them for the market.
“You first need to look at: are there enough potatoes to eat? Then, are we not competing with farmers making income from selling potatoes?” he explains. “So if eating potatoes is covered, selling potatoes is covered, and there are some potatoes left, then yes, it can work.”
“Boiled Potatoes aren’t Fashionable“
Secondly, boiled potato batteries aren’t attractive. It’s hard to disband the perception that they are just some cheap vegetable.
As Gaurav Manchanda, founder of One Degree Solar, explains, “These are all consumers at the end of the day. They need to see the value in it, not only in terms of performance but status.”
For now, alternative energy is taking the more fashionable forms of solar and wind power, as seen with modern investments in infrastructure. No investor or organization has yet helped expand on the potato prototype. [2]
An Update on the Potato Battery
However, further research found less inspiring results. For instance, a student at Binghamton University tried to light one LED and needed to use six potatoes. She tested each potato and found each one only offered about half a volt, which is why she needed half a dozen. Keep in mind that one LED isn’t enough to light up an entire room. In short, it’s a lot of wasted food for only a small amount of power. Unfortunately, the circulating images of a large lightbulb shoved into a spud are grossly exaggerated.
Here’s another issue with the potato battery: it rots and smells bad. Funnily enough, the amperage increases as it rots, but that doesn’t make up for the unpleasant aroma and attracting bugs into the home. Remember, the power comes from the metal electrodes, not the vegetable. The potato itself has no power. And Josh Centers pointed out in a post on The Prepared: “Ocean water would likely work just as well, plus it’s free and won’t rot.” [3]
So, yes, potato batteries are real and can work. However, the flaws outweigh the benefits, which is why they are typically used in school lab experiments but not to power the actual school. But they technically can be used, as one determined man showed. He decided to play the classic game Doom, using potatoes. After failing to power a Raspberry Pi Zero, he successfully powered a TI-84 calculator and played the game on that. But at what cost? Well, a garage full of rotting potatoes.
Sources
- “With a simple trick, the humble spud can be made into a battery, so could potato-powered homes catch on?” BBC. Jonathan Kalan. November 12, 2013
- “A Potato Battery Can Light Up a Room For Over a Month.” Smithsonian Magazine. Tuan C. Nguyen. December 2, 2013
- “Busted: No, a boiled potato won’t power a lightbulb.” The Prepared. Josh Centers. April 1, 2021
Correction Notice (04/11/2022): This article has been updated with newer information. A previous version (published March 10, 2021) erroneously stated that Luigi Galvani conducted experiments with potatoes when he actually used frogs’ legs, and also stated that potatoes produce energy when they instead act as conductors. An additional update was also added challenging the original experiment and the statement that a single potato can light a room for 40 days. The title has been modified to reflect these changes.