The rubbish is pre-sorted. Everything that can be recycled is meant to have been taken out, but even then they are still left with more than 300,000 tonnes a year.
They do not see it as waste here - they see it as energy.
"Four tonnes of waste has the same energy content as one tonne of fuel oil," says the director of the waste-to-energy agency in Oslo, Pal Mikkelsen.
"That means a lot of energy, and we use very little energy to transport it."
One tonne of fuel oil, Mr Mikkelsen says, could heat a house for half a year. In other words, take just part of an English bin lorry's maximum load picked up on the streets of Leeds or Bristol, turn it into energy here - and you can heat a home in Oslo for half a year.
The process is simple. The waste, tonne by tonne of it, is dropped into an incinerator. It soars to 850 degrees.
Not everything is burned. Old tin cans and some mattress springs are left. At the end of the process they are left with ash, metal -which is recycled - and a lot of heat.
The heat boils water. The steam drives a turbine, which produces electricity. And the scalding water is piped off from the plant, to houses and public schools across Oslo.
With tight controls to clean up the gases from the burning, Oslo believes converting waste into energy will help it to halve its carbon dioxide (CO2) emissions within 20 years - making a city, whose wealth was built on oil, one of the greenest on the planet.