London turns sewer-choking 'fatbergs' to fuel

Grease, fat and other wastes from London's ouseholds and businesses are building up like mini-mountains, or so called 'fatbergs', in the city's 19th century sewers. The problem is not just clogging up the underground system, but also costing the company that runs it, more than a million dollars a month. Now there are plans to try to stop part of the problem before it even begins, by installing drain storage, and turning the accumulated fats into renewable fuel for new power stations. Al Jazeera's Emma Hayward reports from London.