Geothermal energy is a fairly well developed technology but there are still many unknowns and subsequent research questions. The construction of a deep geothermal well at the campus serves two purposes: 1. to do further in depth research into geothermal energy and 2. to supply part of the buildings with low carbon (geothermal) heat. This deep geothermal project will have two wells of 2 to 2.5 km deep – a so-called doublet. Hundreds of meters of rock samples will be collected during the drilling allowing scientists a peek into the Delft subsurface. The walls of the wells will be lined with different materials transforming them essentially into a plumbing system to transport warm water upwards (“producer”) and cool water downwards (“injector”). Each of the wells will be fitted with a lot of sensors over the complete length of the wells and in monitoring stations at the surface. Through the sensors the researchers can gather data on how the wells – and the materials they are made of – interact with the environment and the different layers of rock in the subsurface, in particular in the reservoir. The data collected during the operation of the geothermal well on the TU Delft campus will allow us to better understand the Delft geothermal system and geothermal systems in general giving us the opportunity to make efficiency and longevity gains for this and future projects. The fact that this project will be constructed in an urban environment with such a high level of level of monitoring instrumentation makes this project unique. This will generate valuable knowledge about how future geothermal projects can be done in other urban locations.

The first measurements of movements in the subsurface are being done to understand what is happening in the underground before the project is started and operated. In addition, the heating system on campus is being modified so it can be used with geothermal heat. The current plan is to start installing the wells in 2022. There are a lot of remaining research questions that the researchers want to address with this project on site and several PhD projects are underway. A subsequent step is to look into high temperature heat storage so that heat that is brought to the surface when it is not needed, i.e. during the summer, can be stored to be used at an another moment in time (e.g., in winter).