The District Heating network

Three integrated district heating systems

Varmelast is planning the heat production for the supply of local district heating companies' district heating areas in 17 municipalities in the Greater Copenhagen area. 

The transmission systems of CTR and VEKS are one interconnected system which offers a flexible possibility to exchange heat between the different district heating areas as required. For instance, the heat from Avedøre CHP Plant has supplied Copenhagen and conversely the heat from Amager Power Plant may supply the city of Roskilde.

The district heating network supplies district heating to the supply networks in the Greater Copenhagen area and through the distribution networks, district heating is delivered to 17 municipalities in the Copenhagen metropolitan area. The interconnected transmission and distribution networks in the Greater Copenhagen area represent a very large district heating requirement which may be supplied from many different facilities. This also offers an opportunity to make the production of district heating very economically efficient as a production can always be performed at the production facilities which have the lowest production costs at the time of production.

HOFOR's steambased district heating network is also integrated into the total district heating system. The steam borne district heating can be converted into water borne district heating in steam water exchangers placed at H.C. Ørsted Power Plant and Amager Power Plant. Water borne district heating cannot be converted into steam and therefore the steam system places special demands on the work of Varmelast.

Varmelast handles the planning of the heat production and thus ensures the most efficient district heating production financially speaking. The daily operation of the district heating network in the Greater Copenhagen area is, however, handled by CTR and VEKS' control room – physically located in Frederiksberg and Albertslund respectively. When all is said and done, it is the control rooms that ensure that the district heat is supplied to the local district heating companies, also in case the supply at the plant fails.
 

Heat producing units in the Greater Copenhagen area
A. Prioritised production
The waste incineration plants Amager RessourceCenter, Vestforbrænding and ARGO and the Rensningsanlægget Lynetten are politically prioritised production in the district heating system. Likewise the geothermal demonstration/testing unit at Amager is prioritised production. Geothermal energy is utilising hot water from the subsoil.
 
B. Base load 
Together the CHP plants Amager Power Plant – owned by HOFOR – Avedøre CHP Plant and H.C. Ørsted Power Plant – owned by Ørsted – together with the prioritised production from the waste incineration plants and the geothermal testing unit form the foundation for the supply in the Greater Copenhagen area.
Moreover Varmelast uses 2 heat accumulators (heat bunker tanks) in Amager Power Plant and Avedøre CHP Plant respectively, so the heat can be produced at times where the price is as low as possible at the CHP plants (accumulators are filled). Conversely the heat can be used when the district heating requirement is greatest, i.e. in the morning (where the accumulators are emptied). This offers great flexibility and a financial optimisation of the power and heat production.
 
C. Peak and reserve load
Approx. 30 peak load units owned by CTR, VEKS and HOFOR function as reserve for the base load unit – typically upon failures during winter.
Moreover you find a total of 4 large peak and reserve load boilers at Svanemølle Power Plant and H.C. Ørsted Power Plant which are owned by Ørsted. These 4 boilers are so large and relatively economic compared to the smaller peak load units of the district heating companies and they are therefore used more as intermediate load, i.e. they produce heat when the district heating consumption is higher than usual – in particular during winter, in the morning peaks and when the CHP plants fails.