DISTRICT HEATING IN GREATER COPENHAGEN – HISTORY AND STATUS 2023

The background for Denmark’s leading position in the world concerning the spread of district heating is that covering the heating needs of buildings by connecting to district heating has been part of Danish society for more than 100 years- indeed, for almost 120 years.

By Lars Gullev, Senior Consultant, VEKS

Published in Hot Cool, edition no. 1/2023 | ISSN 0904 9681 |

This article provides a quick historical overview of the development of district heating in Greater Copenhagen from the beginning of 1903 until today. Insight into the benchmarks for the further development toward a CO₂-neutral district heating system in Copenhagen 2050 is shared in the article “District heating in Greater Copenhagen – 2050.”

Starting point

Once upon a time – more than 100 years ago -, the city council of Frederiksberg put both the environment and a future-orientated heat supply on the agenda. Frederiksberg is an independent municipality situated in the western part of Copenhagen City. Heat 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 developed from being a village to a town with the nature of a big city. In 1857 – Frederiksberg became an independent municipality ranking as a market town.

The city developed rapidly – industrial enterprises were built, and the factories attracted a workforce. The city grew bigger and bigger – the industry grew, and the population increased. A railway station was built, a fire service was established, schools and a library were built, and the city was provided with gas, running water, sewers, and electricity.

However, the busy activity had a natural – though problematic – “by-product”: waste. Concurrently with the increase in population and the building of the outer area of Frederiksberg, the price of land increased, and it became even more expensive for the municipality to buy land for dumping grounds. At the same time, people were fully aware of the risk of, e.g., cholera by having dumping grounds placed too centrally.

By the end of the 19th century, it was a cagey affair to walk around in the streets of Frederiksberg. Many of the free space areas were bursting with piled-up garbage with consequent odor 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 – to build a waste incineration plant and utilize the surplus for district heating – a so-called Waste-to-Energy (WtE) plant. 

In September 1903, the city of Frederiksberg received its first waste collection at the new waste incineration plant, and the plant was inaugurated. From December 1 of that same year, the district heating production was put into regular operation. 

The heat produced by burning the waste was transported in the form of steam via a tunnel to the newly built Frederiksberg Hospital and an orphanage. With the new steam-based district heating supply, hospital standards were raised. Suddenly, mattresses and operating equipment could be disinfected, and in the large epidemic and tuberculosis department, it was essential to have a sterile environment.

In the following years up to the end of the 1940s, district heating in the municipality of Copenhagen was quietly expanded to supply heat to public buildings – including public bathing facilities. This development took place under the auspices of the company Københavns Belysningsvæsen, which later changed its name to Københavns Energi and today is called HOFOR.

Installation of transmission pipeline in central Copenhagen

Organization of the district heating companies

Until the end of the 1940s, all district heating companies had been municipally owned, but now the development of district heating in the Copenhagen area took off in earnest. In part, the increase in living standards had meant that more citizens could pay for installing water-borne heating systems in their homes – as a replacement for the tiling laws – which made the connection to district heating possible. In part, groups of citizens began to “join together” and establish district heating companies as consumer-owned, collectively owned companies.

The driver for the latter development was the price difference between the expensive gas oil used in individual oil boilers and the cheaper fuel oil that could be used in large communal boilers. The price difference in oil could be used to finance investments in boiler plants to produce district heating and the district heating network. Herein lies a large part of the secret behind satisfaction with district heating in Denmark – the local commitment and ownership.

The industry association Dansk Fjernvarme has organized 354 district heating companies that cover 99% of the district heating needs in Denmark. – the 58 companies are municipally owned and cover 50% of the district heating supply. Of the remainder, 286 companies are consumer-owned, and the remaining ten are private and only cover a tiny part of the district heating market.

The oil crises of 1973 and ’79 – a wake-up call

Until the beginning of 1973, there was no political interest in the district heating sector in Denmark. Still, with a shortage of imported oil – 92% of Denmark’s energy consumption was based on imported oil – and rising oil prices as a consequence of the war between Israel and Egypt in 1973 did, it change. And the war between Iran and Iraq in 1979 – again with a shortage of imported oil and sharply rising oil prices – permanently changed the Danish energy scene.

Heating Supply Act 1979

The Heating Supply Act in 1979, which was the first of its kind in the world, focused on the need for increased energy efficiency in Danish society. This meant, among other things, that where it made sense economically, electricity and heat had to be produced together by so-called combined heat and power production.

This was the start of establishing the two district heating transmission companies – CTR and VEKS – to ensure the utilization of surplus heat from waste energy plants and cogeneration plants in the Copenhagen area. There were two transmission companies due to CTR having to use surplus heat from the waste-to-energy plant Amager Forbrænding and Amager CHP plant, respectively. On the other hand, VEKS had to use the surplus heat partly from the waste energy plant ARGO in Roskilde and partly from the future Avedøre CHP plant.

For outsiders, it may be surprising that two district heating transmission companies were established. It was a political decision that ensured the desired democratic influence among the companies’ stakeholder municipalities.

In the 1980s, Vestforbrænding had significantly greater heat production from burning waste than the company could sell to its district heating customers. Therefore, a pipe connection was established between Vestforbrænding and VEKS, so VEKS’ supply area could use the excess heat instead of cooling it off in cooling towers. Subsequently, a line connection has also been established between Vestforbrænding and CTR, so that excess heat from Vestforbrænding can be delivered to CTR and/or VEKS depending on where the heat demand is most significant.

Figure 1 The transmissionnetwork in Greater Copenhagen

What does the district heating system in Greater Copenhagen look like today?

The system today consists of four more or less linked systems:

• Vestforbrænding, which supplies waste-based district heating to five municipalities, is connected to the district heating transmission networks of CTR and VEKS for excess heat supply.
• HOFOR Varme covers a subset of its customers’ heating needs by directly purchasing district heating from HOFOR Production – and the rest from CTR.
• CTR, which buys biomass-based district heating from the CHP plants Amager and Avedøre – as well as the waste-to-energy plants ARC and Vestforbrænding – sells the heat to five municipalities in the eastern part of Copenhagen.
• VEKS buys biomass-based district heating from the Avedøre CHP plant and from the waste-to-energy plants ARGO and Vestforbrændning. It also has its own biomass-based heat production from a CHP plant in Køge, a biogas engine in Solrød, and excess heat from the industrial company CP Kelco in Køge. VEKS delivers the heat to 19 local distribution companies in 12 municipalities.

The development in the environmental declaration for district heating (kg CO₂/MWh) delivered to an end-customer in VEKS’ supply area shows a reduction in CO₂ emissions of more than 76% in 2020 – the reduction is equivalent for an end-customer at HOFOR and CTR. So, in terms of environmental impact alone, the expansion of district heating in Greater Copenhagen has been a success.

Heat load

Since January 7, 2008, Varmelast has handled the total load dispatching of the Copenhagen metropolitan area. In brief, load dispatching is an economic optimization of heat production hourly in proportion to the production costs and prices on the power market. Varmelast is a cooperation between HOFOR Varme, CTR, and VEKS.

Before the power market liberalization, there were two large producers of district heating in the Copenhagen metropolitan area. The production companies had a joint load dispatching station. Back then, no confidential data were involved as they did not need to consider the liberalized power market.

With the liberalization of the power market in the year 2000, the producers merged so that there was only one big producer of district heating in the Copenhagen metropolitan area, which handled the load dispatching of all the plants.

In 2006, Amager CHP plant was sold off to the Swedish Vattenfall. Out of consideration for the competitive situation of the power market between Ørsted (formerly named DONG) and Vattenfall, the producers could no longer perform the load dispatching for the heating and power production in the Copenhagen metropolitan area on their own. Consequently, it was necessary to find a new solution to ensure the economic optimization of the production across the plants with different owners.

Summary

Today, the district heating system in Greater Copenhagen is characterized by heat production from large central production plants – three conventional CHP plants based on sustainable biomass, three waste-to-energy plants, and peak and reserve load units based on wood pellets, natural gas, and gas oil.

Heat load ensures that the total electricity and heat production in Greater Copenhagen area is optimized on an hourly basis, 24/7/365, so that the lowest total production costs are ensured for the benefit of the district heating customers.

So, a concept – developed more than 100 years ago – remains viable in a world where competing heat producers deliver district heating into the same grid – competing with each other on costs.

For further information please contact: Lars Gullev, lg@veks.dk

Figure 2 Environmental declaration 2020 (average for VEKS’ end customers)

Facts about VEKS

• Founded in 1984 and owned by 12 municipalities in the western part of Greater Copenhagen and along Køge Bay.
• VEKS Transmission supplies 19 local district heating companies with heat in Vestegnen. The supplied heat corresponds to the consumption of 170,000 families. The heat is purchased primarily from Avedøre CHP plant, owned by Ørsted, and from waste-to-energy plants owned by ARGO.
• VEKS owns Køge CHP plant, which produces electricity for the grid, steam for Junckers Industrier A/S, and sells (internally) district heating to VEKS Transmission. It also owns a gas engine in Solrød, which produces electricity for the grid and district heating for VEKS Transmission, based on biogas delivered from Solrød Biogas A/S. Køge District Heating Company handles the distribution of district heating to private consumers, business customers, and institutions in the city of Køge – Tranegilde District heating Company handles the distribution of district heating to customers in the Tranegilde business area in the municipalities of Ishøj and Greve. For both Køge District Heating and Tranegilde District Heating, the heat is purchased internally from VEKS Transmission.
• www.veks.dk

Facts about CTR

• Founded in 1984 and owned by five municipalities in the eastern part of the Copenhagen area – Copenhagen, Frederiksberg, Gentofte, Gladsaxe, and Tårnby.
• Supplies local, municipally owned district heating companies in the five municipalities with heat – including HOFOR. The supplied heat corresponds to the consumption of 250,000 families. The heat is purchased primarily from the Amager CHP plant, owned by HOFOR Energiprocuktion and ARC’s waste-to-energy plant.
• www.ctr.dk

Facts about Vestforbrænding

• Founded in 1970 and owned by 19 municipalities in Zealand, Denmark – supplies district heating to Herlev, Ballerup, Lyngby-Taarbæk, Furesø, and Gladsaxe municipalities – as well as surplus heat to CTR and VEKS.
• Denmark’s largest waste-to-energy company and Northern Europe’s largest waste-based district heating producer handles waste for 900,000 citizens and 60,000 companies.
• In 2021, Vestforbrænding converted almost 500,000 tonnes of waste into heat (1.26 million MWh) and electricity (199,000 MWh).
• www.vestfor.dk

Facts about HOFOR

• Founded in 1857 for the production and distribution of town gas.
• Today, the multi-supply company with activities within the drinking water, wastewater, production and distribution of district heating and cooling, distribution of town gas, and production of district heating and electricity.
• Owns Amager CHP plant, and from here, HOFOR Varme directly buys some of the heat the company must deliver to its end customers. CTR buys the remaining part.
• Has 1,000,000 water customers, 700,000 wastewater customers, 500,000 heating customers, 300,000 town gas customers, and 39 district cooling customers.
• www.hofor.dk