Seville in southern Spain is well known for the bright oranges that are dotted across its 48,000 trees in spring. A draw for tourists, Seville's trees create 5,700 tonnes (5.7 million kg) of the attractive fruit, and while some oranges are shipped to the UK to go into marmalade, or used to create liqueurs such as Cointreau and Grand Marnier, most are left to rot. By winter the city's oranges are causing havoc as they fall onto paths and roads, and the local government has to employ around 200 people to clear them up. But now the city's fruit is set to be used to generate electricity. Click or scroll on to find out how...