Green Solar Cities Site Copenhagen

The CONCERTO activities at Valby are spread over 9 different areas in the city (Map 1). The measures include new building construction as well as refurbishment in the residential, public and commercial sector. Newly implemented renewable energy systems are rather related to buildings than large-scale plants for general energy supply. So the new Water Cultural Centre (public indoor swimming pool, Picture 1) with a floor area of 3,000 m² is supplied by district heating and on its roof there is a 19.1 kWpeak photovoltaic system installed.

In total almost 50,000 m² of new and energy efficient buildings have been constructed at Valby. „Langgadehus“ is a new-built 8,723 m² elderly centre including service areas and 68 dwellings in ground and 1st floor (Picture 2). Additionally there is social housing on 2nd and 3rd floor comprising 59 dwellings of 100 m² each. This building’s heating is supported by 200 m² of solar thermal collectors. At “Dronning Ingrids Plejehjem“ (a housing with 132 dwellings for elderly people) windows with triple glazing were implemented and 60 m² of solar thermal collectors have been integrated on the roof. In the F.L. Smith area 100 housing units and 5,000 m² of commercial buildings are built, where solar heating and cooling will be demonstrated.

At the „Karensminde“ area 36 new-built low energy prefab dwellings for a social housing project (4,300 m² in total) were finished in May 2008 according to Danish low energy class 2 (25% better than actual energy requirements) and CONCERTO standards (30% better). A photovoltaic system of 30,6 kWpeak has been included in spring 2010. Lykkeboskolen is an extension to an existing school with 896 m² for a new sports facility. The building is low energy class 2 and CONCERTO standard with a 3,8 kWpeak PV installation integrated in the roof. Construction started May 2010 and was finished January 2011.

During CONCERTO 19,000 m² of living space have been retrofitted. At the „Hornemanns Vaenge“ area 4 building blocks with a total of 192 dwellings were retrofitted (Picture 3). A pilot project on ventilation systems with heat recovery had been demonstrated in one dwelling and the tenants had approved the installation, so that the ventilation solution was then installed in all dwellings. The roofs have been totally renewed and PV systems have been installed on them. Construction work started in August 2011 and was finished in 2013.

Sjaeloer Railway Station in Valby is the first station in Copenhagen where PV modules supply energy for the platform LED lightning (Picture 4). The total size of PV is 18 kWpeak. An on-going process of renovation of all the railway stations will probably repeat this energy optimization of lighting and PV integration on platform roofs.

In the photovoltaic sector it is Valbys goal to implement a total of 1,000 kWpeak within the CONCERTO framework. Different further small-scale systems have been installed at residential buildings (30 so far, with 40.7 kWpeak in total), a plant of 500 kWpeak is planned to be installed at „Damhusaaen“ (read additional info in the „More detailed“ section).

Large photovoltaic plant

The construction of a large PV plant (500 kWpeak) is in progress, located at the large wastewater treatment site “Damhusaaen” in Valby (Map 1). It will supply electricity also to a sludge bio-gasification system. The PV plant will be situated on top of a former, now filled up 20,000 m² waste water sludge deposit. An area of about 10,000 m² is needed for the 3,500 m² of PV-modules. They are installed with a 45-degree (Picture 5) slope and a certain distance between the PV rows to avoid mutual shading.

Electricity production is calculated with 850 kWh/kWpeak, so that a total amount of 425,000 kWh is predicted to be produced annually.

New dwellings at Karensminde

The CONCERTO project supported the first 36 dwellings in Karensminde belonging to the ambitious program of 5.000 “affordable dwellings” (low cost and low rent) in Copenhagen (Picture 6 + 7). Production facilities for the construction of energy-efficient low-cost family housing were ready, but few were built when the market collapsed due to the financial crises and thus large supply of vacant apartments in Copenhagen.

For the Karensminde apartments the technology of prefabricated room-sized modules is used. They were produced in Estonia, shipped to Copenhagen and transported on lorries to the site. The construction fulfils the low energy class 2 of the Danish building code and is heated by district heating. Subsequent measurements have shown that the building meets the energy class. In Spring 2010 the dwellings have been equipped with photovoltaic systems (30 kWpeak in total, Picture 8).

Lightweight prefabricated housing is
a relatively new technology in Denmark.
The background of using this construction technology was an overheated market for concrete wall, floor and roof units, and a desire to reduce construction costs. Simultaneously there were energy benefits. Experiences from the other Nordic countries have shown that achieving good insulation standards was relatively easy, where thermal bridges were minimized and high air tightness obtained.

(Text taken from Green Solar Cities brochure)