11 Apr 2013: Report

Copenhagen’s Ambitious Push
To Be Carbon Neutral by 2025

The Danish capital is moving rapidly toward a zero-carbon future, as it erects wind farms, transforms its citywide heating systems, promotes energy efficiency, and lures more people out of their cars and onto public transportation and bikes.

by justin gerdes

Among the first sights to greet visitors to Denmark on the descent to Copenhagen’s airport is a sweeping arc of wind turbines rising from the harbor. From the airport, passengers can board an automatic Metro line that hustles them to the city center in just 15 minutes, crossing the path of the City Circle Line, a subway project that will place 85 percent of Copenhageners within 650 yards of a Metro station when the line opens in 2018.

Everywhere, visitors are greeted by streams of bicyclists; 36 percent of trips to work or school in the Danish capital are made by bike, and more than 20,000 cyclists enter the city center at peak hours, filling Copenhagen’s 249 miles of cycle tracks. Less visible are state-of-the-art facilities where waste heat from power plants is used to keep buildings warm via the world’s largest district heating network, or where waters from the city harbor are deployed to cool department stores, office buildings, hotels, and data centers.

View gallery
Wind farm Copenhagen

Wikimedia Commons
The Middelgrunden wind farm in Copenhagen Harbor.
These innovations are just a prelude to what is planned in the coming years, all designed to make Copenhagen the world’s first carbon-neutral capital by 2025. Acting on a City Council plan approved last August, Copenhagen intends to replace coal with biomass, to add more wind and solar electricity to the grid, to upgrade energy-guzzling buildings, and to lure even more residents onto bikes and public transit.

“Copenhageners like the ambition, they like being part of the idea of going green for the whole city,” Copenhagen Lord Mayor Frank Jensen said in an interview with Yale Environment 360. “Our focus as a city, as citizens, is all about livability.” The mayor said that city residents are putting their own money into the low-carbon drive, noting that half of the turbines in the harbor wind farm, known as Middelgrunden, were funded by individual Copenhagen shareholders.

Clearly, Copenhagen’s plans face significant challenges, especially since city planners expect Copenhagen to add more than 100,000 residents by 2025. But at stake is the notion that a growing, modern city with more than a half-million inhabitants can systematically wring carbon from its economy. The battle to slow climate change will be won or lost in cities, which are responsible for more than 70 percent of global CO2 emissions and two-thirds of worldwide energy consumption.

Copenhagen has already made major progress, reducing its emissions by 21 percent from 2005 to 2011. The city currently emits about 2 million tons of carbon dioxide a year, and earlier initiatives were on target to reduce emissions to 1.16 million tons by 2025. The new plan approved last year will slash CO2 emissions even further, to about 400,000 tons by 2025. More time will be needed to wean private cars from fossil fuels. So Copenhagen plans to add at least 100 wind turbines to the grid over the next dozen years, and wind electricity not used in the city will be exported to other parts of Denmark to offset Copenhagen’s remaining several hundred thousand tons of transportation emissions.

Nearly three-quarters of the emissions reductions identified in the 2025 plan will come by transitioning to less carbon-intensive ways of producing heat and electricity. The goal is a diverse but complementary clean energy
The goal is a diverse clean energy supply: biomass, wind, geothermal, and solar.
supply: biomass, wind, geothermal, and solar. “The Danish energy system is very much a systems solution – it’s not power as one, and heat as one — it’s integrated,” Jørgen Abildgaard, Executive Climate Project Director for the city of Copenhagen, says. Wind turbines now supply 30 percent of Denmark’s electricity, and under a national energy plan passed last year that share is set to rise to 50 percent by 2020.

Though not as visible as Copenhagen’s bicyclists and wind turbines, its heating and cooling infrastructure is playing a key role in slashing CO2 emissions. One of Copenhagen’s most innovative infrastructure projects is the Adelgade cooling plant, sheltered within the brick-clad shell of a retired power plant in the historic city center. Opened in June 2010, the plant is the hub of the country’s first district cooling network and a model of climate-conscious engineering.

The Adelgade plant draws cool seawater from an intake pipe located near the picturesque Nyhavn Canal and then delivers the chilled water through insulated pipes to buildings; the pipes are located below ground in the same tunnels in which steam is distributed via Copenhagen’s district heating network. Thomas Grinde, an engineer with Copenhagen Energy — a private firm owned by the city — took me on a tour of the plant. He said that every degree Celsius saved by pre-cooling with seawater saves 15 percent on electricity at the site’s absorption chillers. The city estimates that district cooling reduces carbon emissions by nearly 70 percent and electricity consumption by 80 percent compared to conventional air-conditioning.

From the cooling plant, Grinde drove me south to the Amager power station complex, which sprawls across a spit of land jutting into
Half of Copenhagen’s indoor heating comes from combusting waste.
Copenhagen Harbor. There, a pilot project supplies geothermal heat directly into the district heating system. In March, construction began nearby on a clean-burning waste-to-energy plant that will provide electricity and heating to 150,000 households. According to Mayor Jensen, half of Copenhagen’s indoor heating comes from combusting waste.

The two major combined heat and power (CHP) stations that serve Copenhagen, Amager and Avedøre, largely burn coal. But because waste heat from the stations is sent to the district heating system, they operate at around 90 percent efficiency, compared to around 40 percent for conventional coal-fired power plants. Rather than use furnaces or boilers located in individual buildings for heating, Copenhagen delivers hot water or steam to radiators via a network of pipes covering 98 percent of the city.

Under the climate plan, district heating is to be carbon neutral by 2025. The Amager and Avedøre plants, which today burn a limited amount of biomass imported from Poland, Russia, Sweden, and the Baltic countries, will replace coal entirely with wood chips and straw certified as sustainable by the Danish Energy Association.

Copenhagen’s pursuit of carbon neutrality also rests on its ability to meet demanding energy efficiency and transportation goals. Commercial and residential buildings are to reduce electricity consumption by 20 percent and 10 percent respectively, and total heat consumption is to fall by 20 percent by 2025.

In an interview, Bo Normander, director of the Worldwatch Institute’s Europe office and a Copenhagen City Council member, noted that new buildings in Copenhagen must now be constructed to Denmark’s Low Energy Class ratings; the 2020 standard calls for near net-zero energy buildings.

View gallery
Bicyclists in Copenhagen

City of Copenhagen
More than 20,000 cyclists enter the city center at peak hours, filling Copenhagen's 249 miles of cycle tracks.
It will be considerably harder to achieve energy savings in existing buildings. More than 70 percent of Copenhagen’s buildings were constructed before the introduction of Denmark’s energy efficiency standards, and a major hurdle is the so-called landlord-tenant dilemma, since many Copenhageners rent and neither tenants nor landlords have a strong financial interest in retrofitting buildings to make them more efficient.

“Most of the people here rent,” Marianna Lubanski, executive director of the Copenhagen Cleantech Cluster, told me. “If I own a building, and I have 10 people living there, and I invest a lot of money in energy savings, my tenants will get the savings, not me. We need new ways to share the costs and gains of energy efficiency... Copenhagen can’t succeed with their plan if they don’t find a way.”

She said she would like to see an ESCO (energy service company) market launch in Denmark, where private firms take on the risk of guaranteeing energy savings and in return are paid a fee by landlords or tenants.

Another key component of becoming a net zero-carbon city is further reducing the use of cars. Bo Normander, like many Copenhageners, does not own a car and bikes to work. “It’s the most convenient, quickest, and healthiest way to get around,” he said.

Newcomers to Copenhagen quickly learn the same, as did I. Within a few weeks of starting a job in Copenhagen, in 2008, I abandoned the Metro for a bike, which became my year-round way of getting around, no matter the
By 2025, the city wants 75 percent of trips to be made by foot, bike, or public transit.
weather. Weekday mornings, I pedaled along the perimeter of the cemetery where Hans Christian Andersen and Søren Kierkegaard rest, girding myself for the merge into the horde of bicycle commuters racing along Nørrbrogade, Copenhagen’s busiest bike corridor, toward the city center. It was exhilarating and invigorating, and easily the fastest way to my office. Why would anyone own a car here? I often wondered.

The question is even more relevant today. Intent on reducing transportation’s share of the total city emissions, currently 22 percent, Copenhagen is expanding its cycling and public transit infrastructure to attract even more users. The improvements include “green wave” traffic signals set to the speed of oncoming bikes, angled footrests that enable cyclists to rest without dismounting at intersections, and an additional 44 miles of cycle tracks — paved paths separated from cars and pedestrians by curbs. To entice suburban commuters to abandon cars for bikes, Copenhagen is partnering with neighboring cities to add wider, smoother, better-lit cycle tracks. In April 2012, the first so-called “bike superhighway,” an 11-mile link connecting Albertslund with Copenhagen, opened. Two more are under construction and a total of 26 are planned, Normander said. By 2025, the city wants 75 percent of trips to be made by foot, bike, or public transit.


On Biking, Why Can’t the U.S.
Learn Lessons from Europe?

On Biking, Why Can’t the U.S. Learn Lessons from Europe?
Building bike paths alone will not get people out of their cars in the U.S. and onto bicycles. To create a thriving bike culture in America’s cities, writes Elisabeth Rosenthal people must begin to view bicycling as Europeans do — not just as a way of exercising, but as a serious form of urban mass transportation.
The city will also invest in alternative fuels. Abildgaard said Copenhagen is looking to convert its bus fleet to models powered by hybrid drives running on biogas. The city projects that 20 percent to 30 percent of all cars and small trucks, and 30 percent to 40 percent of all heavy vehicles, will run on electricity, hydrogen, biogas, or bioethanol by 2025. By 2015, 85 percent of the city’s fleet of 1,000 small vehicles will run on electricity, hydrogen, or biofuels, officials say.

What will all this cost? Direct city investment in the 2025 Climate Plan is estimated to be $472 million through 2025. Add private funds and total investment could hit $4.78 billion over the same period, Copenhagen officials say. “We can see that we have to invest a lot of money to reach the target,” Mayor Jensen told me. “But we can see also that we can create a lot of new jobs with that huge investment. Copenhagen can be a green laboratory for developing and testing new green solutions.”

Normander was upfront about the challenges. He will be watching to see, for instance, if the Avedøre and Amager power plants can sustainably source enough biomass. And he worries that as Copenhagen adds 1,000 residents per month, traffic will increase, even though the city lacks room for additional cars.

“It’s a very ambitious plan,” he said. “But it’s also something we can do.”

POSTED ON 11 Apr 2013 IN Business & Innovation Climate Energy Energy Policy & Politics Policy & Politics Urbanization Europe North America 


Justin - A profoundly encouraging article. Copenhagen may have been an abject failure in 2009, but the city got the real message. We need every city on the planet to emulate Copenhagen's efforts.

But when you mentioned the Adelgade plant drawing sea water for distributive cooling, I realized what I'd forgot: Copenhagen is at sea level. I googled "Copenhagen sea level" and got this website from Carbon Virgin: http://vimeo.com/29258933 Carbon Virgin gives an excellent explanation of how they derive their videos here:

All of Copenhagen's heroic efforts to go zero carbon will be for naught if every individual and country doesn’t join together and deeply recognize we all live in Copenhagen. At a recent Keystone XL rally there was a sign that said it perfectly. "There is no planet B". We are all on the same life raft.

Posted by Wayne Roth on 11 Apr 2013

Thanks for your comments, Wayne. I had hoped that the article would inspire the optimism you took from it.

Copenhagen is blessed with abundant resources -- not every city will be able to deploy seawater-assisted district cooling or offshore wind farms -- but that shouldn't lead other cities to be discouraged about their own potential to put in place a plan to achieve carbon neutrality.

One of the key takeaways from the Copenhagen example was expressed by the city climate official Jørgen Abildgaard in our interview: Denmark's is a systems solution, using diverse and complementary sources of heat and electricity. It's all about developing a plan that gets the most from the renewable clean energy resources available wherever the city happens to be.

Posted by Justin Gerdes on 11 Apr 2013

Already the emissions of Copenhagen was some 20 percent lower in 2005, compared to 1990, so emissions by now are about 40 percent below 1990.

On the minus side, systems definition is derived from the Kyoto protocol, which means that overseas travel and consumption of products produced outside Copenhagen are not included. Thus total carbon footprint of the individual citizen will still be considerable in 2025.

With full respect of the efforts of the municipality of Copenhagen, when talking climate impacts we need to redefine the definition of the city to include the full carbon footprint of activities the citizens.

While Copenhagen city may reach carbon neutrality by 2025, each citizen may still have a carbon footprint of some 10-15 ton per person per year.

Posted by Jens Hvass on 12 Apr 2013

Laudable goal, but have to agree with Jens. A lot of smoke, mirrors and PR.

CO2 neutral biomass?

CO2 neutral waste (read plastic) combustion?

Danes (the happiest nation on the planet) have a self delusion issue.

But to their credit - they've got the rest of the world believing them!

Posted by Richard Owen on 13 Apr 2013

Thank you Justin for an interesting article. I actually live close to the Adelgade plant, but didn't realize that we are using seawater for cooling in there! I am happy that my city has made a bold plan - let's hope we can fulfill it!

On the notion of resources: it's always easy to find the excuses - but like you say in your comment - let every city find its own means to reduce carbon emissions. It would be easy to complain that we don't really have to much sun power here in DK! I am sure that the most important is the will and commitment at make sustainable choices and change.

Posted by Signe Waldorff Bonde on 13 Apr 2013

Jens: You are right to note that one should remember that his or her carbon footprint includes air travel (especially long international flights) and goods purchased that are manufactured overseas.

But these are concerns better tackled by nations, not cities. That's why the slow work underway at the International Maritime Organization and International Civil Aviation Organization to improve the fuel efficiency of commercial ships and planes is so important. Carbon emissions from these sectors are growing rapidly. Precisely because these emissions span borders we need a global solution. Another possibility could be to include aviation and shipping in the UNFCCC agreement to be reached in Paris in 2015.

Richard: You are much too ready to dismiss the good-faith efforts being undertaken in Copenhagen. The 2025 Climate Plan is hardly "a lot of smoke, mirrors and PR." You are correct to note that researchers are still working to more accurately gauge the sustainability of biomass-fired electricity. But, as I noted in the piece, the City of Copenhagen has already committed to follow sourcing rules for biomass developed by a third party. Also, because Copenhagen depends on CHP power stations that are connected to a district heating network, they are much more efficient than conventional plants -- an important point when burning biomass, which has a lower energy density than coal.

Last, and I did not have the space to get into this in the piece, you mention the complication of plastic combustion in Copenhagen's waste-to-energy plants. The 2025 Climate Plan includes the city's commitment to remove plastic from the waste stream. Copenhagen recently rolled out plastic recycling for the first time.

Posted by Justin Gerdes on 14 Apr 2013

Yes. Denmark has been the very early countries promoting eco friendly green technologies. I lived in Denmark for couple of years.

Denmark was a pioneer in developing commercial wind power during the 1970s, and today almost 50 percent of the wind turbines around the world are produced by Danish manufacturers such as Vestas and Siemens Wind Power along with many component suppliers. Wind power provided 18.9 percent of electricity production and 24.1 percent of generation capacity in Denmark in 2008. In 2012 the Danish government adopted a plan to increase the share of electricity production from wind to 50 percent by 2020.

To encourage investment in wind power, families were offered a tax exemption for generating
their own electricity within their own or an adjoining commune. While this could involve
purchasing a turbine outright, more often families purchased shares in wind turbine
cooperatives which in turn invested in community wind turbines. By 1996 there were around 2,100 such cooperatives in the country. Opinion polls show that this direct involvement has helped the popularity of wind turbines, with some 86 percent of Danes supporting wind energy when compared with existing fuel sources.

The role of wind turbine cooperatives is not limited to single turbines. The Middelgrunden offshore wind farm – with 20 turbines the world's largest offshore farm at the time it was built in 2000 – is 50 percent owned by the 10,000 investors in the Middelgrunden Wind Turbine Cooperative, and 50 percent by the municipal utility company. By 2001 over 100,000 families belonged to wind turbine cooperatives, which had installed 86 percent of all the wind turbines in Denmark. By 2004 over 150,000 were either members or owned turbines, and about 5,500 turbines had been installed, although with greater private sector involvement the proportion owned by cooperatives had fallen to 75 percent. The cooperative model has also spread to Germany and the Netherlands.

The transition to a clean, “green” energy economy will rely on the same mixed-bag that serves the real economy, with offshore wind leading. But solar will also be a part of that mix, along with biomass, geothermal and heat pumps. The solar photovoltaic (PV) portion of that mix will be aimed primarily at residential and small business, and used to supplement wind. The advantage of solar PV being a fallback for wind is a curious synergy between the two technologies created by Nature herself the sun doesn’t shine at night, which is when wind blows hardest!Larger solar installations will also provide some district heating, either as solar PV or passive heating technologies, and all forms of solar are expected to be able to contribute at least half of the clean energy mix, especially as cutting-edge renewable energy storage technologies are instituted.

Yet Denmark is determined to be carbon-free by mid-century, proving yet again that cleaning up one’s environmental act is more a matter of political will and the cooperation of concerned individuals, companies and leaders than it is a financial or social mandate.

Dr. A. Jagadeesh Nellore (AP), India

Posted by Dr.A.Jagadeesh on 15 Apr 2013

Extraordinary, this is the commitment that is required. But why do they still burn waste when they could use Elementa's non incinerating, non polluting, steam reformation?

Posted by Gary blokhuis on 20 Apr 2013

This goal is more achievable than the current thinking seems to imagine. This is by far the most progressive overall plan I've seen, Done properly combustion could be virtually eliminated and any biological "Waste" could be returned to the soils as carbon enhancement for better food productivity.

Posted by william r williams on 21 Apr 2013


Comments are moderated and will be reviewed before they are posted to ensure they are on topic, relevant, and not abusive. They may be edited for length and clarity. By filling out this form, you give Yale Environment 360 permission to publish this comment.

Email address 
Please type the text shown in the graphic.

justin gerdesABOUT THE AUTHOR
Justin Gerdes is an independent journalist specializing in energy issues who is based in Concord, California. His work has appeared at Forbes.com, Motherjones.com, GreenBiz.com, and Chinadialogue. From October 2008 to December 2009, he worked as an editor and writer for Monday Morning, a publishing house and think tank based in Copenhagen. The reporting for this article was supported by a grant from the Danish Ministry of Foreign Affairs International Press Initiative.



One Scientist’s Hopeful View
On How to Repair the Planet

Ecological crises may be piling up in a seemingly hopeless cascade, but Swedish scientist Johan Rockström says the next few decades offer an unparalleled opportunity to undo the damage.

Beyond Sprawl: A New Vision of
The Solar Suburbs of the Future

The concept of the "solar suburb" includes a solar panel on every roof, an electric vehicle in every garage, ultra-efficient home batteries to store excess energy, and the easy transfer of electricity among house, car, and grid. But will the technological pieces fall in place to make this dream a reality?

In South Korea, An Innovative
Push to Cut Back on Food Waste


In a Host of Small Sources,
Scientists See Energy Windfall

The emerging field of “energy scavenging” is drawing on a wide array of untapped energy sources­ — including radio waves, vibrations created by moving objects, and waste heat from computers or car exhaust systems — to generate electricity and boost efficiency.

How High Tech is Helping
Bring Clean Water to India

Anand Shah runs a company that is using solar-powered “water ATMs” to bring clean water to remote villages in India. In an e360 interview, Shah talks about how his company is using a high-tech approach to address one of India’s most intractable public health issues.


MORE IN Reports

A New Global Tinderbox:
The World’s Northern Forests

by ed struzik
Rapidly rising temperatures, changes in precipitation, and increased lightning strikes are leading to ever-larger wildfires in the northern forests of Alaska, Canada, and Siberia, with potentially severe ecological consequences.

For U.S. Tribes, a Movement to
Revive Native Foods and Lands

by cheryl katz
On ancestral lands, the Fond du Lac band in Minnesota is planting wild rice and restoring wetlands damaged by dams, industry, and logging. Their efforts are part of a growing trend by Native Americans to bring back traditional food sources and heal scarred landscapes.

Beyond Sprawl: A New Vision of
The Solar Suburbs of the Future

by marc gunther
The concept of the "solar suburb" includes a solar panel on every roof, an electric vehicle in every garage, ultra-efficient home batteries to store excess energy, and the easy transfer of electricity among house, car, and grid. But will the technological pieces fall in place to make this dream a reality?

Natura 2000: EU Reserves Are
Facing Development Pressures

by christian schwagerl
An astonishing 18 percent of the European Union’s land area is protected under a network of preserves known as Natura 2000. Now, at the urging of business interests and farmers, the EU is examining whether regulations on development in these areas should be loosened.

As Ocean Waters Heat Up,
A Quest to Create ‘Super Corals’

by nicola jones
With the world’s coral reefs increasingly threatened by warmer and more acidic seas, scientists are selectively breeding corals to create species with the best chance to survive in the coming century and beyond. Are genetically modified corals next?

A Clash of Green and Brown:
Germany Struggles to End Coal

by christian schwagerl
A recent battle over imposing a “climate fee” on coal-fired power plants highlights Germany’s continuing paradox: Even as the nation aspires to be a renewable energy leader, it is exploiting its vast reserves of dirty brown coal.

On an Unspoiled Caribbean Isle,
Grand Plans for Big Tourist Port

by fred pearce
East Caicos is a tropical jewel – the largest uninhabitated island in the Caribbean and home to rare birds and pristine turtle-nesting beaches. But plans for a giant port for cruise and cargo ships could change it forever.

A Little Fish with Big Impact
In Trouble on U.S. West Coast

by elizabeth grossman
Scientists are concerned that officials waited too long to order a ban on U.S. Pacific sardine fishing that goes into effect July 1. The dire state of the sardine population is a cautionary tale about overharvesting these and other forage fish that are a critical part of the marine food web.

Despite Hurdles, Solar Power in
Australia Is Too Robust to Kill

by jo chandler
No nation has as high a penetration of residential solar as Australia, with one in five homes now powered by the sun. And while the government has slashed incentives, solar energy continues to grow, thanks to a steep drop in the cost of PV panels and the country’s abundant sunshine.

Genetically Modified Mosquito
Sparks a Controversy in Florida

by lisa palmer
Officials in the Florida Keys are seeking to use a GM mosquito that could help prevent a recurrence of dengue fever there. But fears among some residents — which scientists say are unfounded — are slowing the release of mosquitoes whose offspring are genetically programmed to die.

e360 digest
Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies


Donate to Yale Environment 360
Yale Environment 360 Newsletter



About e360
Submission Guidelines

E360 en Español

Universia partnership
Yale Environment 360 articles are now available in Spanish and Portuguese on Universia, the online educational network.
Visit the site.


e360 Digest
Video Reports


Business & Innovation
Policy & Politics
Pollution & Health
Science & Technology


Antarctica and the Arctic
Central & South America
Middle East
North America


Photographer Robert Wintner documents the exquisite beauty and biodiversity of Cuba’s unspoiled coral reefs.
View the gallery.


The latest
from Yale
Environment 360
is now available for mobile devices at e360.yale.edu/mobile.

e360 VIDEO

Warriors of Qiugang
The Warriors of Qiugang, a Yale Environment 360 video, chronicles a Chinese village’s fight against a polluting chemical plant. It was nominated for a 2011 Academy Award for Best Documentary Short.
Watch the video.

header image
Top Image: aerial view of Iceland. © Google & TerraMetrics.


A three-part series Tainted Harvest looks at the soil pollution crisis in China, the threat it poses to the food supply, and the complexity of any cleanup.
Read the series.