Here are the latest renderings of BIG's combined power plant and ski slope that blows smoke rings, which commenced construction in Copenhagen yesterday (+ slideshow).

The Amager Bakke Waste-to-Energy Plant was designed as a replacement for the existing Amagerforbraending plant. The huge wedge-shaped building will also generate power by incinerating waste. A 31,000-square-metre ski slope will trail down the roof of the structure, allowing it to double-up as a new visitor attraction.

A chimney will extend up from the top of the slope and will emit a smoke ring every time a ton of carbon dioxide has been released, intended to remind local residents of their carbon footprint. These rings will be illuminated by lasers at night.

The Amager Bakke plant will stand in an industrial zone near the city centre and is described by the architects as "the single largest environmental initiative in Denmark".

The ground-breaking ceremony took place on-site yesterday and was attended by officials from the City of Copenhagen and members of the local community.

Read more about the Amager Bakke Waste-to-Energy Plant in our earlier story on Dezeen. The project is also included in Dezeen Book of Ideas, which is on sale now for £12.

BIG, short for Bjarke Ingels Group, is also currently working on a 150-metre-high skyscraper for Vancouver and two twisted apartment blocks for Miami. See more architecture by BIG.

Here's a few words from BIG:

BIG celebrates the groundbreaking of Amager Bakke Waste-to-Energy Plant

Located in an industrial area near the city centre the new Waste-to-Energy plant will be an exemplary model in the field of waste management and energy production, as well as an architectural landmark in the cityscape of Copenhagen. The project is the single largest environmental initiative in Denmark and replaces the adjacent outdated Amagerforbraending plant, integrating the latest technologies in waste treatment and environmental performance.

Amager Bakke reflects the progressive vision for a new type of waste treatment facility and is conceived as a destination in itself.

The roof of the new Amager Bakke is turned into a ski slope of varying skill levels for the citizens of Copenhagen, its neighboring municipalities and visitors, mobilizing the architecture and redefining the relationship between the waste plant and the city by expanding the existing recreational activities in the surrounding area into a new breed of waste-to-energy plant.

Amager Bakke Waste-to-Energy Plant is included in our book, Dezeen Book of Ideas. Buy it now for just £12.