Using Rubbish to Power Homes

What if your rubbish could heat your home, power your lights, charge your devices and also do something about ‘that waste problem’.

The Copenhagen’s iconic waste-to-energy plant does all of that above, but also adds a new fun activity to people living in the area. This architectural and scientific marvel turns rubbish into electricity and heating for thousands of homes and businesses. And if to top it off (literally) there’s a ‘dry’ ski slope on the roof.

It starts with a truck full of rubbish

Every day, up to 300 trucks roll into “Amager Bakke”, each carrying waste that can’t be recycled. Only what truly can’t be reused ends up here. That part is crucial because recycling comes first but we also need to find a solution for what cannot be recycled.

The waste is dumped into a massive concrete silo that is about half the size of a football field and as tall as a 10-story building. Inside, two huge robotic grabby hands scoop and mix the rubbish like stirring a giant pot. This makes sure everything burns smoothly later on.

Those same robotic grabby hands then drop the waste into incinerators. To keep the air clean, the whole room is kept under lower air pressure, so odours don’t escape, and the sucked-in air is reused in the burning process.

The incinerators then burn the waste at around 1,000°C, which is hot enough to break down just about anything.

The hot smoke from burning waste travels through giant boilers filled with tightly packed pipes full of water. As the heat rises, the water turns to steam and this steam powers turbines.

Each tonne of rubbish produces enough energy to heat multiple homes.

Credit: BIG

The Ash

After burning, what’s left is a grey, gravelly ash called slag. It’s about 20% of the original waste by weight and contains metals, glass, sand and anything else that doesn’t burn.

From here the slag is processed so that recyclable metals like iron and aluminium are recovered, and the rest is turned into material for construction projects, like roads or foundations.

The Air

Before the smoke leaves the plant, it goes through one an advanced purification systems. It’s scrubbed, filtered, cooled, and cleaned across multiple stages to remove dust, acid gases, mercury, and nitrogen oxides.

What finally exits the chimney is mostly water vapor and harmless gases. This process is constantly monitored to ensure it stays that way and no harm can be caused to anyone breathing the air in.

The Water

There is up to 13,000 litres of water per hour being used in this plant. So what happens with that?

This water is cleaned through a four-step process, involving everything from lime neutralisation to carbon filters and ammonia recovery. Nothing leaves the plant untreated. Even the leftover sludge gets pressed and safely disposed of with other byproducts.

Credit: Dragoer Luftfoto

A Model for the Future

More than just a power plant, Amager Bakke is a symbol of what’s possible when cities embrace sustainability, smart design, and bold ideas. It shows that waste, that has historically been a huge problem, can be turned into a powerful resource.

And with a ski slope, hiking trails, and a climbing wall built into its design, it also proves that industrial buildings don’t have to be eyesores. They can be inspiring, fun, and fully integrated into the life of a city.

This is a great example of what happens when cities combine sustainability, design, and creative thinking. It proves that waste doesn’t have to be a burden; it can be a valuable resource.

Could this be the future in NZ?

An application has been received to build a similar waste to energy plant Te Awamutu which is currently in public consultation.

The proposal is sparking significant debate. Proponents argue it offers a modern solution to landfill challenges. While opponents raise concerns not only about environmental impacts, but mainly about community health. The discussion highlights the complexities of balancing waste management needs with sustainable practices. It would be good to understand the specific technologies proposed, and what the environmental and health impacts of the project really are.

Will this type of waste solution be the future for us in NZ?

Let us know what you think!