Spanish engineers have updated the old citrus cliché, bringing it into the eco era — when life gives you oranges, make electricity. In Seville, they’re repurposing the many tons of fruit that the city’s 48,000 orange trees drop in the streets. Instead of a sticky, pulpy wintertime hazard, the methane from these rotting oranges will soon generate clean energy.
Seville’s municipal water company, Emasesa, will start this new program by using 35 tons of fruit in a facility that already turns organic matter into electricity. The methane captured from fermenting oranges will drive the generators for water purification plants. If the orange experiment is successful, old fruit could one day supply the grid with surplus power. Scientists report that early trials show that 1,000 kilograms of oranges can fuel five homes for a day. If all of Seville’s oranges were harvested, they could power 73,000 homes.
“We hope that soon we will be able to recycle all the city’s oranges,” said Benigno López, the head of Emasesa’s environmental department, as reported by The Guardian. “The juice is fructose made up of very short carbon chains and the energetic performance of these carbon chains during the fermentation process is very high. It’s not just about saving money. The oranges are a problem for the city and we’re producing added value from waste.” López estimated that Seville would need to invest 250,000 euros (about $300,000) to accomplish this.
Oranges were introduced to Spain about 1,000 years ago. “They have taken root here, they’re resistant to pollution and have adapted well to the region,” said Fernando Mora Figueroa, head of the Seville’s parks department. “People say the city of Seville is the world’s largest orange grove.”
Locals don’t eat typically eat the bitter oranges. Instead, they drop, rot and attract flies. The city employs 200 people to pick up the fallen fruit.
Via The Guardian
Image via Hans Braxmeier