As far as sustainability credentials go, Copenhagen is a model city.
In 2016, the Danish capital was ranked the world’s greenest city by consulting firm Dual Citizen. Some 35,000 of its residents – around half its population – commute to work by bike every day. Among its streets can be found organic restaurants, eco-hotels and green spaces, as the city bids to be the first carbon-neutral metropolis by 2025.
Visitors to Copenhagen over the last five years or so may also have noticed a monolith, composed of brilliant glass and aluminium, taking shape in the near distance; the edifice in question being the Amager Bakke, a new waste-to-energy plant.
When the idea of constructing such a plant was first mooted in 2011, the reception among the architectural community was one of incredulity – not least concerning the blueprint to incorporate a publicly accessible artificial ski slope into of its roof. Renowned as one of the world’s flattest countries, Denmark is not known for its skiing prowess.
Yet, the Amager Bakke plant is on schedule to be completed this autumn, Bjarke Ingels Group (BIG), the local architecture firm behind the project, have confirmed. BIG has acquired a name for itself for ambitious undertakings, and is also working with ‘starchitect’ Thomas Heatherwick on Google’s new swanky headquarters in London.
BIG ambitions: The world’s most efficient waste-to-energy plant
Back in Copenhagen, the vital numbers around the Amager Bakke plant are impressive. It will provide low-carbon energy to 550,000 people, delivering heating to over 140,000 households. The plant, claims BIG, will be able to treat more than 400,000t of waste each year, with an energy efficiency of 107%; the highest in the world for a waste-to-energy plant.
BIG has partnered with engineering group Ramboll on the project, with the latter providing planning and commissioning services. This includes the provision of wet flue gas condensation and heat pumps, so as to optimise heat production.
According to Ramboll, the new facility will also be able to export energy in the forms of both hot water and electricity straight to the local grid. Furthermore, 15% – 20% of incoming waste can be reused for the purposes of road construction.
It is understandable why Amager Bakke has courted so much publicity since ground was broken on the project in 2013. It does away with the idea of a power plants – or industrial buildings in general – as being clinical monoliths that are hard on the eye.
BIG is expecting up to 57,000 visitors to the site in the first year to take advantage of the ski slope. Standing at 88m high and 10m wide, Amager Bakke will also house one of the world’s tallest artificial climbing walls.
Smoke rings and safety nets: What can we expect to see from Amager Bakke come September?
There are still questions, however, around some of the project’s most unique concepts. When setting out its initial vision for Amager Bakke, BIG claimed the plant would bellow out a giant smoke ring from its stack by way of symbolising the conversion of waste (250 kilograms of carbon dioxide) to clean power.
In 2015, the firm even released a video of a successful trial for a smoke-ring-blowing chimney. According to local media reports at the time, BIG was said to be working with aerospace engineer Peter Madsen, co-founder of non-profit group Copenhagen Suborbitals, on a prototype of the technology.
But it is not known whether this feature will see the light of day in the final design. BIG could not be reached for comment for this article, while the latest renderings of the plant show no depiction whatsoever of smoke rings being pumped into the sky.
Project director Patrik Gustavsson, speaking to the Guardian in November 2016, said: “BIG is still working on the smoke rings; it is not clear yet if it has a viable solution or not, but we’re crossing our fingers.”
It also isn’t clear how safety will be ensured for skiers utilising the 440-metre-long slope. In the same interview with the Guardian, Gustavsson said BIG was working with “some of the world’s most renowned ski security experts”, and had looked into the possibility of “using nets as safety devices” as a precaution in case any skier went over the edge.
However, recent renderings from BIG and SLA – which has designed the plant’s rooftop park – show no sign of outer netting.
The birds and the bees: SLA and the construction of the rooftop activity park
While the ski slope may have attracted the biggest headlines, SLA’s rooftop activity park is arguably just as innovative in its utilisation of an element of a building that, in most cases, is commonly unused. During the summer, the park will play host to hiking trails, playgrounds, trail running and climbing walls.
SLA is also seeking to create a nature reserve for birds, bees, butterflies and insects, which, according to firm partner Rasmus Astrup, “will mean a dramatic increase in the biodiversity of the area”.
Speaking earlier this year, Astrup confirmed that the rooftop park has been something of a labour of love for SLA, and not without its challenges.
“The project to create an attractive and green activity rooftop park on top of Amager Bakke has been very challenging,” he said.
“Not only because of the extreme natural – and unnatural – conditions of the site and the rooftop itself, which put severe stress on plants, trees and landscape. But also because we’ve had to ensure that the rooftop’s many activities are realised in an accessible, intuitive and inviting manner. recreational public space with a strong aesthetic and sensuous city nature that gives value for all Copenhageners – all year round.”
When it finally comes online in September, Amager Bakke has the potential to set a precedent in terms of bringing energy-efficient environmentalism to the fore in urban areas – even in a city as green as Copenhagen. For all the excitement generated around ski slopes and climbing walls, this will be the project’s overriding function – and hopefully its legacy.