Since the launch of the MAKING-CITY project in December 2018, Groningen started converting two districts in PED areas. Joep de Boer, from WarmteStad, features the first achievements that have been done in the Dutch city, which is one of the two Lighthouse cities of the MAKING-CITY project.
We have connected the two Nijestee flats at the end of 2019 to our heat grid in the PED North. Currently, we are providing residents with heat for central heating and domestic hot water. The geothermal district heating network in Groningen North is initially designed as a high temperature network. However, the heating source has been changed to waste heat of data centers instead of geothermal energy. The district heating network has been adjusted to a high to medium temperature district heating network. This means that the temperature would be approximately 75 °C in summer and up to 90 °C during cold days in the winter.
To connect the retrofitted buildings of Nijestee to a high temperature heating network instead of gas, the existing local heating system has to be adjusted by installing a mix of heat transformer. This innovated mix injection will be used to control the supply temperature to the apartments of Nijestee buildings independently from the supply temperature of the heat grid.
The connection between the heat grid and the retrofitted buildings of Nijestee has been made in the last months of 2019. The last adjustments on the local heating system are currently made. WarmteStad will provide heat for space heating and domestic hot water to the residents of the retrofitted buildings of Nijestee from the beginning of 2020.
We have taken 214 households off the gas by connecting the two Nijestee flats to our heat grid.
Watch the Video for a local news channel showing the connection of the Nijestee flats!
In the PED South, the Powerhouse building has been connected to our collective aquifer thermal energy system (ATES). In order to switch between groundwater for heating and groundwater for cooling a wheatstone bridge is installed. The groundwater is subsequently used as a source for the heat pumps or directly for passive cooling. WarmteStad has installed in the Powerhouse project a high efficiency high-temperature heat pump. This ground source heat pump has been installed in order to make hot water for central heating and domestic hot water (65 °C). Despite the large temperature difference, the heat pump works very efficiently.