Energy supplier N-Ergie implements near-surface geothermal project in Kornburg district of Nuremberg

Source: Energy & Management Powernews, October 10, 2022

For the residential area "RieterBogen" in Kornburg, N-Ergie opens up the ground for the laying of lines for geothermal energy use by means of a line plow.

According to the motto "Use the energy that is stored under our feet", the Nuremberg energy supplier N-Ergie is currently building a geothermal plant for the future residents at the "RieterBogen" in the Kornburg district of Nuremberg. A pipeline plow is currently underway on a field there, digging a total of around 16 kilometers of pipelines to a depth of around two meters. The plastic pipes are laid horizontally and are part of a near-surface geothermal surface collector covering about 1.3 hectares.

"In Kornburg, we are implementing our first near-surface geothermal project," said Gregor Mannl, head of plant engineering at N-Ergie Kraftwerke. It is one of the largest plants of its kind in northern Bavaria. "For the heat turnaround to succeed, we need to exploit the potential of all heat sources," Mannl added. For the project, only such a near-surface solution came into question, as geothermal probes are not possible due to the soil conditions in Kornburg.

Ground heat for around 100 living rooms

Solar radiation, seeping rainwater and air temperatures ensure that the ground stores heat, which can be used again when needed, especially in autumn and winter. A heat transfer medium in the pipe collector extracts heat from the ground and transports it to the buildings via a local heating network that is around 2.5 kilometers long in total. It concerns so-called "cold local heat", because the attached 100 houses and dwellings are supplied with heat gain over the heat transfer medium, which is only 8 degrees or less warm.

To be able to use this local heat temperature for heating and for warm water, each building is equipped with a heat pump, whose river is produced proportionately by Photovoltaik plants on the house roofs. Here, primary energy factors are achieved that are below 0.4 due to the well-chosen heat pumps in the houses. CO2 emissions are reduced to less than half of a conventional heating system and can be further reduced by using photovoltaic electricity.

Over the surface collector can be tilled again

In the next few months, the collector and the associated local heating network will be constructed, so that by the end of the year the first buildings can be heated. The completion of the local heating network is expected in 2024. After the work, the installation of the area collector will be invisible, and the field can be used for agricultural purposes again.

In the Rieter Bogen neighborhood, which is named after the patrician Rieter family, around 150 residential units in the form of condominiums, terraced houses and semi-detached houses will be realized by 2025, as things stand today.

Author: Susanne Harmsen