Topping this month’s Top 10 is Seville’s water utility Emasesa and its biogas pilot, which transforms the seasonal nuisance of fallen oranges into an innovative green energy solution. The city’s 48,000 orange trees produce more than 5.7 million kilograms of bitter oranges each winter, which typically litter the streets. Now, these unwanted fruits are being put to good use through the Emasesa Biogas Pilot project.

Municipal water company Emasesa is spearheading this initiative by harnessing the natural fermentation process of oranges to generate clean electricity. The project currently utilises 35 tonnes of fruit to power one of the city’s water purification plants.

Benigno López, Emasesa’s Head of Environment, has ambitious plans for the future. With an investment of €250,000 (US$267,800), the company aims to recycle all of Seville’s surplus oranges. This could potentially generate enough energy to power 73,000 homes, significantly boosting the city’s renewable energy capacity.