Copenhagen gets heating tunnel

The municipal heating utility Københavns Energi (Copenhagen Energy) is building a tunnel that will secure economical and environment-friendly heating for the inhabitants of the Danish capital. NIB’s financing covers half of the EUR 100 million project.

A four-kilometre tunnel is being constructed 35 metres underground in central Copenhagen. The tunnel pipes will carry 300-degree hot steam and water to the city’s district heating network. The works commenced during summer 2005. According to Carsten Bankel, Københavns Energi’s Cash Manager, the drilling of the tunnel was completed as planned in April 2007 and within the budget. The tunnel is set to be completed by 2009.

“We are in the process of modernising the heating supply network in Copenhagen. When ready, the operation costs of the upgraded network will be much lower,” says Astrid Birnbaum, head of the heating network at Københavns Energi. The company expects a cost reduction of about DKK 50 million per year.

The heating supply provided by the utility will be more environmentfriendly, because heat will be produced at a new thermo plant on the island of Amager in eastern Copenhagen. The new tunnel will also help reduce the city’s annual carbon dioxide emissions by 200,000 tonnes. It corresponds to the gas exhaust of 53,000 cars.

The heating mains will be connected to the network through three shafts: one is being constructed on Amager; the second in the vicinity of Amalienborg, the royal palace, in the very heart of the city; and the third one is located two kilometres further westward. Since the diameter of the tunnel is more than four metres, people can freely move about and operate in it when carrying out inspections or repairs.

“This is rather important for the maintenance of communications in a large city. We don’t have to dig up the streets and disturb the traffi c, if we need to get down to our mains,” Ms Birnbaum comments on the innovative approach.

The project is estimated to cost DKK 750 million, which corresponds to EUR 100 million. Despite such a large investment, the heating bills from the utility will not grow in the foreseeable future. The modernisation of the heating supply network will help prevent heating tariffs from swelling by reducing loss of heat.

Construction of the tunnel was necessary because the heating supply company Energi E2 is currently upgrading its heat production facilities. District heating services are provided to 98% of the inhabitants and organisations of Copenhagen, of whom two thirds receive heating as hot water. A number of large consumers, for instance, hospitals and hotels, in the central part of the city are provided heating with the help of hot steam.

“We plan to switch all of our heating consumers to hot water, including those in central Copenhagen. The new tunnel will allow us to upgrade the heating supply shortly after the construction is fi nished. This modernisation will secure a reliable heating supply for years into the future,” Ms Birnbaum concludes.