REMINING-LOWEX Site Heerlen

New buildings will be constructed in two demonstration areas. The first is “Heerlerheide Centre” with 33,000 m² of single-family dwellings and residential buildings (312 units), 3,800 m² of commercial buildings, 2,500 m² of public and cultural buildings, 11,500 m² of health care and 2,200 m² of educational buildings (Picture 1 and 2). At the “Stadspark Oranje Nassau” (SON) 12,100 m² of dwellings (110 units), 19,000 m² of offices, a hotel of 4,000 m² and a large-scale commercial complex are being built. At some buildings photovoltaic panels are used as sunshields for windows, which move according to the position of the sun.

In September 2009 the new CBS office building with 21,000 m² floor area was commissioned (Picture 3). A monitoring is continuously performed and provides all the stakeholders (in a special examination group) with information for improvement and optimization.

In a large scale Heerlen makes use of the geothermal energy by their former mine shafts. Therefore mine water is extracted from different wells with different temperature levels (Picture 4). The extracted mine water is transported by a primary energy grid to local energy stations and in a secondary grid from energy stations to buildings. The secondary energy grid provides low temperature heating (~ 35 – 40 °C) and high temperature cooling (16 – 18 °C) supply and one combined return (20 – 23 °C). Where necessary local sub-energy stations as heat pumps, small-scale CHP units or condensing gas boilers are installed in the buildings for preparation of domestic hot water, depending on the type of building and the specific energy profile. Learn more in the “more detailed” section.

District heating and cooling by minewater

Two warm wells (HH1 and HH2, 700 meters deep) are located in the north-west of Heerlen. Two cold wells (HLN1 and HLN2, 200 meters deep) are located in the middle and southern part of Heerlen and an intermediate well (HLN3, 450 meters) is located near the cold well HLN1. A primary distribution grid is constructed between the wells and the local energy stations (Map 1 + Table 1 as legend).

Thermal exhaustion must be avoided by careful management of the in- and outgoing energy flows, especially if the requested heat and cold increases because of new connections to the grids.

The temperature levels of the heating and cooling supply are “guarded” in the local energy stations by a poly-generation concept, which comprises heat pumps in combination with gas-fired boilers and a bidirectional grid. The bidirectional grid allows storing surplus heat from buildings (for example, in summer, cooling, process heat) back to the mine water wells. Monitoring the energy station indicates new opportunities for further improvement of the energy performance, especially in balancing the mine water energy and the residual heat of the supermarket.

For making efficient use of the low-exergy energy sources new buildings should fulfill special standards which were defined by the involved stakeholders at Herleen and are shown in Table 2. They concern insulation of the building and efficiency of building services and are compared to national regulation and building standard of the year 2007 in the Netherlands.

For the region of Heerlen the cooling and heating demand was estimated and it could be shown that there is a huge potential in extending the heating and cooling grid (Table 3). Up to 28,000 GJ heating and 51,600 GJ cooling per year would be needed in this region. Therefore the big building complexes in Heerlen were split into different construction phases with prioritisation to obtain the most efficient connection to the grid as soon as possible.

Table 1 – Legend to the satellite map

Table 2 – Specifications for buildings to use low exergy in Herleen

Table 3 – Overview of the estimated heating and cooling demand for the region of Heerlen