Design City

THE CITY OF COPENHAGEN: CARBON NEUTRALITY FOR SUSTAINABLE CITY DEVELOPMENT

t设计都市DESIGN OF URBAN

Low-carbon urban life in Copenhagen Photo credit: Visual China Group

Low-carbon urban life in Copenhagen Photo credit: Visual China Group

Following Chinese president Xi Jinping’s announcement at the general debate of the 75th session of the United Nations General Assembly to reach peak carbon dioxide emissions by 2030 and carbon neutrality by 2060, China has been vigorously rolling out policies and measures to achieve the above targets. Cities are not only the primary source of global carbon emissions, but also one of the direct victims of climate change. 

According to statistics, cities emit roughly 75% of the world’s carbon dioxide , and 90% of them are adversely affected by climate change, such as sea level rise and extreme weathers. As China further pushes forward with its urbanization drive, urban carbon neutrality through proper design and planning will become a key field that merits thorough explorations.
 
图片Wind generators in Oresund, Copenhagen Photo credit: Visual China Group
 
As early as in 2009, the City of Copenhagen released a 16-year climate plan, announcing that it would become the world’s first carbon-neutral city. The initiation of actions to address climate change will help reduce carbon dioxide emissions by a large margin. Accordingto the plan, the city sets out to reduce its current carbon emissions from 2.5 million tons to less than 1.2 million tons. The plan is now progressing steadily. In 2011, Copenhagen’s carbon emissions dropped by 21%, compared with 2005. By 2015, the city had achieved the goal of reducing emissions by 20% – far ahead of schedule. As indicated bythe latest data, Copenhagen’s carbon emissions in 2019 stood at around 1.4 million tons, a 42% decrease from 2005.
 
After the release of the zero-emission plan, the government of the City of Copenhagen proposed 50 specific initiatives. One example is the district heating grid. Now, 98% of local homes are connected to the heating grid, which is mainly powered by the advanced and efficient waste incineration facility. Some other examples of initiatives are the promotion of green mobility (walking, cycling and public transportation) and the development of electric and hydrogen-fueled cars. Today, half of the local population travel mainly by bike. This move alone reduces air pollution, noise, accidents and congestion costs up to USD 43 million every year. In addition, power plants in the city are required to use wind, geothermal and biomass energy to generate electricity; also, private capital is encouraged to invest in green energy development.
 
图片Source: Visual China Group
 
Energy Consumption
 
Although energy consumption only accounts for 7% of emission reductions, it is one of the most economically efficient ways to reduce emissions. Based on this, Copenhagen is expected to cut heating costs by about DKK 500 million (approximately USD 80 million) every year through energy savings.
 
Today, 63% of all Danish households are connected to the district heating grid, which supplies them with heating and domestic water. By co-generating heat and power (also known as combined heat and power, CHP, technology), the overall energy efficiency is much higher than that of heating and power generation separately. The energy use efficiency of heat and power co-generation can be as high as 85-90%, which can save about 30% of fuel compared with separate production. District heating and CHP have become and will continue to be a key factor in Denmark’s green transition. The successful experience in the City of Copenhagen shows that district heating is one of the most flexible energy production and supply methods with the lowest carbon emission.
 
The integrated district heating grid in Greater Copenhagen provides one million residents in 22 municipalities with cost-effective, low-carbon heating.
 
First built in the mid-1920s, Copenhagen’s central heating system was extensively expanded in the 1970s. Due to excessive reliance on scarce and expensive fossil fuels, the burning of coal and oil deteriorated the air quality of the city. Despite air pollution, the then district heating grid suffered from a low energy distribution efficiency. Since 1995, it is precisely because of the more efficient district heating system that Copenhagen has cut carbon emissions by a large margin and improved the city’s livability.
 
The reduction in energy consumption of buildings is attributed to the efficient heating systems. The Danish government has been committed to cutting buildings’ energy consumption and increasing the proportion of renewable energy use by various means, such as laws and regulations, finance and taxation, and other administrative measures. The introduction of energy efficiency indicators for new buildings, as well as the collection of heating fuel taxes for buildings nationwide, worked together to sharply lower the net heating energy per square meter of building space. Currently, the heating energy consumption of newly built buildings in Denmark only accounts for about 25% of that before 1977. The latest Danish building regulations outline explicit requirements for energy consumption levels of new buildings constructed between 2015 and 2020 and set out agoal to ensure new buildings will have “almost zero energy consumption” and mainly rely on renewable energy supplies.
 
The best-known green building in Copenhagen is the Green Lighthouse, Denmark’s first zero-emission public building, which was inaugurated in November 2009.
 
图片Green Lighthouse  Source: www.velux.com.cn
 
Located on the campus of the University of Copenhagen, the Green Lighthouse was designed and built by the Copenhagen City Government, the University of Copenhagen, the Danish University and Property Agency, and the VELUX Group. It cost DKK 37 million (approximately USD 5.92 million) and is integrated with many functions such as recreation and convention services. The building is currently used as a teaching building by the Faculty of Science at the University of Copenhagen.
 

 

The Green Lighthouse is a round-shaped building. With its green exterior wall, the structure harmoniously integrates into its surrounding environment. The design of its adjustable blinds allows the entire building to collect the maximum amount of sunlight. Constructed in a positive and active way, the house, while achieving zero carbon emissions and reducing energy consumption, has also opened up new ways to use renewable energy.
 
图片Green Lighthouse  Source: www.velux.com.cn
 
Walking into the Lighthouse, one will immediately feel its optimal lighting effect. It is the scientific and unique design that helps the building greatly reduce its energy consumption. As one of the most typical smart green buildings in the post-industrial era, it boasts a healthy indoor climate and plenty of natural daylight.
 
According to Lone Feifer, Programme Director of VELUX Group, daylight is the primary source of energy for the Green Lighthouse. The automatically-adjustable roof windows ensure sufficient indoor lighting. Without these roof windows, the building would not be able to use solar energy as a heating source and would need a large number of electric lights to achieve the same lighting effect. Installed with light sensors, lighting equipment inthe building will detect the conditions where there is not enough light and automatically adjust the brightness to appropriate levels. This kind of illumination control can help cut electricity bills by more than 30%.
 
图片Green Lighthouse  Source: www.velux.com.cn
 
Energy Supply
 
The power and heat generation is currently the biggest source of carbon emissions in the City of Copenhagen. Through a series of measures such as building new wind power farms and biomass-fueled heating plants, Copenhagen’s goal, to achieve by 2025,is to generate one unit of renewable energy with every unit of fossil fuel consumed. By doing so, the city is expected to reduce carbon emissions by nearly 900,000 tons, which will account for nearly 80% of the total reduction.
 
When the plane is about to arrive at the Copenhagen Airport, you will see a spectacular scene outside the window: at the end of the blue sea lies a green city; what is more magnificent is rows of rotating wind turbines on the sea.
 
图片
Wind generators in Oresund, Copenhagen  Photo credit: Visual China Group
 
Although wind power has taken a large share in its energy system, Copenhagen continues to invest huge sums of money in building more wind power farms. Located outside the Copenhagen Harbor, Middelgrunden is an offshore wind farm with 20 turbines (2 MW each) and a total installed capacity of 40 MW. The farm supplies power to 40,000households in Copenhagen. Now, it has become a new landmark or namecard of the city, attracting hundreds of thousands of people to visit and learn from the successful experience every year.
 
The City of Copenhagen also uses the heat generated by waste incineration to provide heating for the city. The waste comes from eight garbage sorting bins placed in each residential building. Back in 1988, more than 40% of the city’s waste was sent to landfill, while the percentage is now only 1.9%. Around 60% of waste in the city is recycled, and the rest is used to generate heat fed into the district heating grid.
 
图片CopenHill Power Plant, Copenhagen  Photo credit: Visual China Group
 
Green Mobility
 
In Copenhagen, transportation is the single sector that accounts for the largest proportion of carbon emissions, which is up to one-third of its total and is still on the rise. How to further increase the proportion of journeys on foot, by bike or by public transportas well as the proportion of vehicles using new fuels is an initiative crucial to reducing the 140,000 tons of carbon emissions in the traffic sector.
 
Copenhagen is well-known as the “City of Cyclists”. In its urban areas, cyclists can be seen zipping through traffic like fish in the ocean. The ubiquitous flow of bikes has become part of the city’s cultural symbol.
 
图片
People cycling in the city of Copenhagen  Photo credit: Visual China Group
 
To effectively solve the problems of carbon emissions from vehicles and urban traffic congestion, the City of Copenhagen has vigorously promoted bikes as a means of transportation in recent years, thus setting off a bike revolution. Over one-third of Copenhageners now cycle to work orschool every day. The cyclists that you see everywhere in the city cover all age groups, from teenage students to seniors in their sixties. Everyone rides briskly on the exclusive blue bike lanes, forming an eye-catching landscape unique to Copenhagen.
 
Driving in Copenhagen, you have to stop and wait for endless red lights. However, cycling turns out to be a completely different experience: if you ride at a constant speed, you will hit green lights all the way to your destination.
 
In Copenhagen, all traffic lights are coordinated according to the average speed of cyclists. As indicated by the official statistics, for cyclists in Copenhagen, the average cycling speed reaches 15 km/h, while that of car drivers is only 27 km/h. The small area of Copenhagen makes parking a big problem. Drivers sometimes need to search several blocks for a parking space. It usually takes at least ten minutes. So, to get to the destination faster, cycling proves to be a better alternative. This also reveals the different degrees of importance Copenhagen attaches to various modes of transport: bikes are in first place, public transport follows as the second, and private cars are the last one. Moreover, cycling is also a great workout, conducive to the health of all people. As a fairly economical means of transport, it will free cyclists from the troubles of auto loans, taxes, rising oil prices, and parking fees, to name a few.
 
图片Digital Statistical System for Cycling in Copenhagen  Photo credit: Visual China Group
 
The mayor of Copenhagen, Frank Jensen, said cities “can change the way we behave, the way we are living, and go more green.”
 
In the latest CPH 2025 Climate Plan, the government of the City of Copenhagen hopes to increase the proportion of journeys to work or school by bike from over 30% to 50%. To this end, the government has also developed “super highways” for cyclists. These lanes are specially designed to minimize the number of stops along the route and adopt a special traffic signal system that allows cyclists to hit green lights all the way on their journeys. Besides, along the bike lanes, there are gas stations, repair stands, stops and other facilities that make sure that cyclists can reach their destinations safely. The newly built bike super highways enable the city to reduce carbon dioxide emissions by 7,000 tons every year. Since cycling helps to improve people’s health, there is also an annual saving of DKK 300 million (approximately USD 48 million) in health costs. More and more Copenhageners now choose cycling as their preferred mode of mobility.
 

 

图片People riding bicycle on the bridge, Copenhagen  Photo credit: Visual China Group
 
More than half of the world’s population now lives in cities, and this proportion will continue to increase. Sustainable cities constitute an integral part of the global efforts to achieve sustainable development. Copenhagen’s creative solutions to emission reductions in the fields of energy, mobility, architecture and beyond may shed some light for other cities in the world. Cutting carbon emissions is an important task for cities wanting to attain sustainable development. A sustainable city must be a livable city: a good place where people can live, breathe, work and entertain effortlessly and pleasantly.

 

 

Text / Zhang Zhipeng