How do you turn rubbish into energy?
24 September 2013 Last updated at 00:37 BST
Oslo is one of the greenest cities in the world, with plans to halve its carbon emissions by 2020.
Key to achieving this is the country's biggest energy recovery facility, the Klemetsrud plant, which generates energy by burning rubbish.
At full capacity, the plant will provide all the heat and electricity for Oslo's schools and heat for 56,000 homes.
Europe correspondent Matthew Price looks at how the plant turns waste into much-needed energy.