© TU Dresden / Doppelacker
Heat collected on farmland
The KollWeb 4.0 research project based at the Technical University of Dresden has developed a special plough that can efficiently lay heat collectors just below the ground. This creates the basis for the use of agrithermal energy – heat collected from agricultural land. This technology can be used to supply entire settlements via cold heat networks. The project, which is coordinated by Doppelacker GmhB from Petershagen, seeks to efficiently harness geothermal energy from shallow depths, so that it can be used for the network-based supply of low-temperature heat.
9.2% of all agricultural land would be sufficient
The high level of interest generated by the project, which is receiving funding from the Federal Government’s Energy Research Programme, can be explained by the fact that just 9.2% of Germany’s agricultural land would be enough to supply all German households with heat and warm water. Reference installations in Wüstenrot, Neumarkt and Coswig use heat from farmland to supply private households via cold heat networks.
A special plough is used to lay pipelines parallel to one another around two meters below the ground, leaving the layers of soil intact and allowing farmers to continue to farm and harvest. This dual use of their land generates additional income for them, without compromising their harvest. Up until the arrival of the project, the use of heat collectors in the soil used to compete with other forms of soil use and was therefore restricted to small and unused plots of land.
This is how the heat is distributed and used
The heat collected is then fed into a ‘cold heating network’ that ensures temperatures of five to fifteen degrees. It is then taken to the consumers, for instance in newly-built neighbourhoods, where heat pumps heat it up further to the temperatures required for heating and warm water. Alternatively, it can also be used for cooling.
Unlike conventional heat networks that transport waste heat and operate with major losses, col heat network offer a supply of local geothermal heat that works throughout the year. This type of geothermal heating and cooling delivers unique efficiency and independence.