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3 examples of holistic urban solutions: an energy perspective

By State of Green, March 01, 2018

Our cities are growing and so is the need to make them more sustainable and liveable. In this month’s article, we gather 3 examples of holistic urban solutions from the energy world that contribute to creating liveable cities.

Creating liveable cities means taking a holistic approach to urban development. Doing so enables the development of smart, urban solutions that not only make cities sustainable, but also healthy, safe and attractive places to live in.

Danish cities, companies, consultants and utilities have a longstanding tradition in implementing urban development projects that have been conceived through holistic planning where concern for the environment, people and businesses go hand in hand.

In May 2017, a broad range of Danish organisations united to create a knowledge hub for Danish city solutions – State of Green CITIES. Each month we will bring you a perspective from one of the members on how they work and contribute to holistic urban development in Denmark and around the world. This month DI Energy provides you with 5 examples of holistic urban solutions that energy companies contribute to.

1. Nordhavn, Copenhagen


Photo Credit: By og Havn

Nordhavn (North Harbour) is the new waterfront city district in Copenhagen. The area is being transformed from an active industrial port into a modern residential and business quarter. When completed, Nordhavn will have room for 40,000 residents and an equal number of work places. The overall vision for Nordhavn is for it to be Copenhagen’s premier sustainable district, showcasing how Denmark works with holistic urban planning in practice.

Creating a sustainable city is not just about environmental responsibility. It is also about value creation and social diversity. Nordhavn is designed to enhance Copenhagen’s identity as an eco-metropolis. Renewable energy, new forms of energy supply, optimum use of resources and environmentally friendly modes of transport all help to make Nordhavn a pioneering neighbourhood for sustainable urban development and environmentally friendly buildings.

EnergyLab Nordhavn  New Urban Energy Infrastructures
EnergyLab Nordhavn is a project that utilises a full-scale smart city energy lab. It demonstrates how electricity and heating, energy-efficient buildings and electric transport can be integrated into an intelligent, flexible and optimised energy system. The project contributes to the grand challenge of transforming the energy system in a way that allows it for the efficient integration of a large share of renewable energy – something that supports both international and national climate goals.

The project focuses on the cost-effective, smart energy system that integrates multiple energy infrastructures (electricity, thermal, and transportation) and provides an intelligent control of subsystems and components – providing necessary energy flexibility for efficient utilization of renewable energy. Data will be collected from private residents and businesses. Consumers will have the possibility to automatically control lighting, ventilation and heating, as well as allowing an aggregator to externally control and thereby support a future demand response market.

Showroom and EnergyHub
EnergyLab Nordhavn, Urban Help and Scion DTU have entered into a strong collaboration on EnergyHub, which is a new innovation environment for businesses engaged in innovative and sustainable solutions for the cities of the future. In addition to inviting new businesses to join shared office facilities with focus on sustainable urban development and energy solutions, the partners behind the EnergyLab Nordhavn project have established a showroom which presents the solutions they develop in the living urban laboratory.

2. Hafencity, Hamburg


Photo Credit: Danfoss

With HafenCity, a whole new city quarter has been created, which spans 155 hectares of harbour area in the heart of Hamburg. In developing a new city area along the Elbe, Hamburg is setting new standards  A lively city with a maritime air is taking shape, bringing together workplace and residential inhabitants, cultural, leisure, tourism and retail facilities – quite unlike downtowns dominated by nothing but offices and shops that resemble ghost towns in the evenings. What sets Hafencity apart from other major international urban waterside development projects is the area’s ultra central location and the high expectations of quality reflected, for instance, in its fine-grained mix of uses, standards of urbanity and ecological sustainability, as well as its innovative development process.

District Heating – integrating multiple fuels and technologies
The supply of thermal energy in HafenCity is safeguarded through a mix of concepts that are both innovative and sustainable. City planners have chosen a sustainable and economically advantageous long-term solution for heat supply: All buildings are supplied through district heating.

The aim has been to develop an energy supply concept that fulfils the strictest economic and environmental requirements. In essence, the concept is based on the combination of the existing, well-proven Hamburg district heating system with decentralised, local heating distribution units. The fuel used is mainly coal, along with household and industrial waste, natural gas, and very small quantities of light fuel oil. To further reduce carbon dioxide emissions, the existing HafenCity heating plan is equipped as a pilot plant with a steam turbine and a fuel cell. In addition, two new combined heat and power plants are planned in the Überseequartier and at the cruise ship terminal.

District heating may be supplemented by locally produced heating for example by decentralized combined heat and power units, fuel cells or solar plants completes the energy mix. For air conditioning purposes, heat pumps or geothermal energy are also gaining popularity. Residential buildings are equipped with thermal solar panels for the central domestic hot water supply. The combination of heat and power ensures that surplus heat from the power plant is used to heat buildings in the HafenCity area instead of being wasted. In this way, 90% of the primary energy can be utilised – a concept which could easily be expanded to other residential areas and cities.

In Germany, approximately 14% of all households are connected to district heating systems. The city of Hamburg stands out as a front runner in district heating. The city has a vast district heating network supplying 19% of all households. Politicians in charge have declared that the district heating infrastructure will continue to be expanded. The goal is to connect 50,000 additional households to the district heating network by year 2020.

3. District Cooling for the liveable and climate friendly city

In the capital of Denmark, district cooling results in approximately a 70% reduction in CO2 emissions and a 40% reduction in total costs compared to conventional cooling.

Increasing demand for cooling
There is an increasing demand for air conditioning and cooling in Copenhagen, as in many other cities around the world. The Copenhagen utility company, HOFOR, has built a district cooling system, which consists of a distribution net and two cooling plants. The district cooling system uses seawater to chill the water supplied to the customers. The system supplies commercial buildings such as banks, department stores and offices as well as cooling for data centres and other processes all year round. Therefore, HOFOR can meet the increased demand for cooling in Copenhagen and help reduce CO2 emissions by up to 30,000 tonnes each year. The cooling system now supplies the centre of Copenhagen with cold water, and the pipe system is expanded in order to supply more customers in the future.

HOFOR’s district cooling activities are the biggest of their kind in Denmark. The first cooling plant was opened in 2010, the second plant in 2013, and the system is still under expansion. From 2015 until 2020, it is the ambition to expand district cooling further by doubling the amount of customers and thereby contribute further to Copenhagen’s target to become CO2-neutral in 2025.

Reducing CO2-emissions via the use of seawater
In winter months, the chilled water to the customers is produced by using seawater. The seawater is pumped into the cooling plant through a pipe from the harbour. The seawater temperature is a maximum of 6 °C, when it is used directly to cool down the water for the customers. This is known as zero-carbon cooling. However, a small amount of electricity is used when pumping seawater into the cooling plant. In summer months, when the seawater is not sufficiently cold, energy must be used to chill down the water. Seawater is used to increase the efficiency of the other installations. Using seawater to remove the heat from the machines reduces electricity consumption by up to 70% compared to a local compressor. Also during summer months, waste heat from the power plants is used for cooling. This method is known as absorption cooling and is only used when waste heat from the power plants is available. The absorber minimises CO2-emissions.

District cooling  – livability with multiple benefits
District cooling ensures a comfortable indoor environment without noise and vibrations. District cooling takes up less space than traditional cooling which is a clear benefit in a dense urban environment. A cooling system with an estimated usage of 1 MW will free up 115m2 on the roof, since all cooling towers are removed and 80 m2 in the basement where a large traditional cooling system can be replaced by small, efficient heat exchanger. Further, it provides a high reliability of supply and means lower cost for operation, maintenance, energy fuel and capital.

About State of Green CITIES
The members of State of Green CITIES represent different Danish competencies within holistic urban solutions. The members include State of Green, Confederation of Danish Industry, Danish Energy Association, Danish Association of Architectural Firms, FRI (the Danish Association of Consulting Engineers), DI Energy, DI Byg, DI Digital, DI Transport.

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