Potatoes are, by nature, a great battery acid and a simple trick can transform a simple potato into a cost-effective cell that can light up a room. The only required materials are an anode such as zinc (i.e. anodized nails) which acts as the negative anode, and a cathode such as copper (i.e. pennies), which acts as the positively charged electrode. Acid contained inside the potato responds with a chemical reaction when electrons flow from one material to the other, with energy being released as a result. (See diagram above)
Recently, researchers such as Haim Rabinowitch at the Hebrew University of Jerusalem began to look at the concept of ‘potato power’ in depth. His team found for example that a potato boiled for 8 minutes is 10 times more effective as a battery than a raw potato and that a boiled potato can help to power enough LED lamps to light a room for 40 days.
Interestingly, the potato is hardly alone in its ability to act as a natural battery acid. Many natural materials such as bananas and strawberries are rich in electrolytes and can form the same chemical reaction that occurs in potatoes. But what sets potatoes apart is that, as compared to strawberries, they are relatively inexpensive and easy to store for long periods of time. Additionally, they are the fourth largest food crop in the world and grown across the topics and subtropics. And this makes them particularly interesting to researchers such as Rabinowitch because of their potential to bring affordable energy to underdeveloped or remote areas that are not on the grid.
But given the cost factors and available of the material, why hasn’t the idea taken off?
Lack of awareness by governments and agencies is a starting point but so too is an issue that applies to many biobased materials that are farmed, that being the difficulty of ensuring that valuable agricultural land is not used at the expense of global food production.
Furthermore, the actual feasibility of potato energy is an issue. The potato itself of course not the source of energy itself but rather a kind of battery acid. The actual source of energy is extracted through the corrosion of zinc and this means that both the zinc and the potato need to be frequently replaced.
Nevertheless, at the cost of one-tenth of the price of an AA battery, potato power may yet find its niche.