The Danish district heating history
Once upon a time - more than 100 years ago, both the environment and a future-orientated heat supply were put on the agenda of the city council of Frederiksberg which is an independent municipality situated in the western part of Copenhagen City. Combined heat and power production based on household waste incineration then became the starting signal for the development of district heating in the municipality.

In the 19th century, Frederiksberg develops from being a village to being a town with the nature of a big city. In the middle of the century - in 1857 - Frederiksberg becomes an independent municipality ranking as market town, and during the 19th century, the city develops rapidly. Industrial enterprises are being built and the factories attract manpower. The city grows bigger and bigger - the industry grows and the population increases. A railway station is built, a fire service is established, schools and a library are built, and the city is provided with gas, running water, sewers and electricity.

100 years ago, daily waste was collected and transported by horse carriages to the city dump

However, the busy activity has a natural - though difficult - "by-product": waste. Concurrently with the increase in population and the building of the outer area of Frederiksberg, the price of land increases, and it becomes even more expensive for the municipality to buy land for dumping grounds. At the same time, people are fully aware of the risk of e.g. cholera by having dumping grounds that are placed too centrally.

By the end of the 19th century, it was therefore a dubious affair to walk around in the streets of Frederiksberg. Many of the free space areas were bursting with piled up garbage with consequent odour problems. The municipality struggled with mountains of waste from the rapidly growing population. The lack of dumping grounds meant that the waste from the 75,000 inhabitants accumulated and the fear arose that epidemics would break out. The municipality therefore had to come up with new thoughts.

City dumps created many problems for the nearby city

In 1898 therefore, a few railway carriages were loaded with typical Frederiksberg waste and driven to Germany in order to investigate the possibility of following the example of Hamburg. Here, in 1896, a plant had been developed to burn waste with the facility to utilise the generated heat. The test result came out positive and in the spring of 1902 Frederiksberg Municipality decided to build Denmark´s first waste incineration plant, which not only produced heat but also electricity.

Open burning of garbage in a city dump was the only solution to get rid of the garbage and prevent diseases to spread

Denmark´s first district heating power plant
In September 1903, the first refuse collection was received at the new waste incineration plant and the plant was inaugurated. From December 1 that same year, the district heating production was put into regular operation. The waste was transported in horse-drawn carriages by a slope up to a balcony in first-floor height, where it was loaded into silos and from there, in portions, loaded further into the ovens. In the shape of steam the heat was led through tunnels to the newly built hospital of the municipality and to a children´s home and a poorhouse.


The first waste incineration and CHP plant in Denmark was inaugurated in 1903. Today, the buildings serve as a cultural centre

In this way, Frederiksberg municipality killed two birds with one stone: the problems of disposing of household refuse in an environmentally sound way were solved by establishing a waste incineration plant and at the same time, the waste heat from the combustion process could be utilised for heating municipal institutions. By doing so, Frederiksberg Municipality gave birth to the first district heating system in Denmark.

This district heating initiative inspired many communities in Denmark and already in the beginning of the 1920´es, a number of small and medium-sized diesel-powered electricity generating plants had been established in many small towns. Also here, the surplus heat in the cooling water was utilised for the customers closest by - mainly substations for public offices and houses.

 In some waste incineration plants, horse carriages were lifted by elevators to dump the waste into the plant

The centralised form of heat supply grew steadily in the 20´es and 30´es, and gradually regular district heating substations appeared in connection with the development of large adjoining housing areas.

When the power stations in the large cities changed from diesel to steam heating in the 30´es, many of them were carried out as combined heat and power plants, since the earlier development had obliged the stations to deliver heat as well.

Lack of fuel
During the infancy of district heating, i.e. the period leading up to WW II, the district heating production units were small and only supplied heat to limited local areas. Since the production units at that time were situated in the cities close to the consumers, costs for the transportation of district heating water were also modest.

Such systems are still in use in the US today, where the systems use steam as heat media ensuing large operating and maintenance costs. In the US today, heat is only considered to be a by-product of power generation. In a historical perspective, these conditions have been a significant obstacle to a systematic expansion of the supply of district heating in the US. Europe went through a completely different evolution. The district heating systems have primarily, at least in the Scandinavian countries, been established via public control, often municipal.

During the Second World War the lack of diesel oil made it difficult to maintain the heat supply from the combined heat and power plants, and some plant owners were therefore forced to establish back-up heating, using solid fuel heat-only boilers. After the normalisation of the oil deliverances, these plants represented excess capacity and therefore created a basis for expanding the heating supply networks.

After the war, the structure in the electricity supply in Denmark changed towards large central power plants, and consequently many of the local plants were closed down. This made it necessary to build heating stations, in order to supply the already established district heating systems.

Consequences of the energy crises
The drastic development of the Danish district heating sector began when the energy crisis hit the western countries in 1973/74. At that time, energy consumption per inhabitant was extremely high. The outcome of the crisis was, however, that it became necessary to save energy in Denmark, including energy for space heating. One reason for this was that the heating budgets were all of a sudden multiplied, and another was that Denmark at the time imported almost 100% of all the fossil fuels required to generate heat.

Therefore, the Danish government was forced to devise methods for saving fuels in order to safeguard the interests of society and to reduce the consumers´ heat bills.

Please see "Development" for further information

Today, waste incineration occurs in modern, high-technological energy plants. This waste incineration plant, inaugurated in 2003, is situated in Esbjerg in the western part of Denmark