Whether we like it or not, urine is an essential part of our everyday lives, and researchers have studied for decades how to harness it to generate electricity.
In 2014, scientists at a robotics laboratory in Bristol managed to charge a mobile phone from urine. Now, a recent study has further advanced research on the use of urine as an energy source, lowering the price of its application and speeding up the process. But, how is the implementation of urine as an energy resource currently developing? And how can you get energy from it? Here we tell you.
Recycling a trillion liters of waste
Urine, along with other human organic waste, has been used for various purposes throughout history. Not surprising, considering that a human being produces an average of 800 to 2,000 milliliters of urine per day. If they are multiplied by the total population of the globe, the result is 1.4 trillion liters of urine per day that - most of the time - ends up in the drain.
This huge amount of waste requires proper handling, which is costly and energy intensive. "Waste treatment represents a large part of the daily demand for energy," said Mirella Di Lorenzo, co-author of a recent research. "We want to use the waste as an energy source rather than subjecting it to energy-intensive treatment," Di Lorenzo told Deutsche Welle.
Getting the best out of the trash
Converting urine into electricity involves obtaining energy from bacteria. By removing oxygen from the environment, bacteria break down urine and generate electrons instead of carbon dioxide and water.
Electrochemical devices called bacterial fuel cells convert the charge in urinary fluid into electricity extremely efficiently. Although they are effective, until now these bacterial cells were too expensive, and produced a very low level of energy.
Those are the two main challenges that Di Lorenzo and his team had to face. The new miniature fuel cells are much smaller and have titanium and cloth wires instead of platinum. In addition, they can increase energy production thanks to a protein from egg white.
"The amount of energy produced is still very low," said Di Lorenzo. "But we are not too far from practical applications." The team is confident that our waste will soon be a source of energy for everyday life.
Di Lorenzo knows that urine is not likely to generate as much energy as the sun or the wind, which made the project look critical. But since it is a waste product that will always exist, he believes that the balance between what goes in and what goes out is beneficial. "It is not about urine becoming an alternative to other renewable energies," explained the researcher, "but rather as a complement."
Urine could be used as an energy resource in small services prepared to channel waste directly from our homes to a treatment center and avoiding sanitary problems. Whether or not urine can be transformed into energy on a large scale is uncertain. And if people would accept to use their own waste to produce that energy, it is also. But while those puzzles are being solved, the researchers continue to work on their idea. "Many are quite excited about that idea," said Di Lorenzo, "of course as long as we don't ask them to transport it themselves."