ITER Project (Improving Thermal Efficiency of horizontal ground heat exchangers) is a research project funded by the European Commission focused on improving heat transfer efficiency of very shallow geothermal systems (http://cordis.europa.eu/project/rcn/196092_en.html).
Shallow geothermal energy is the thermal energy that can be stored into and/or recovered by the underground, usually until 100-150 m depth from the ground level, by means of ground coupled heating-cooling systems (i.e. Ground Source heat Pumps – GSHP) or thermal storage systems (i.e. Underground Thermal Energy Storage – UTES) (http://regeocities.eu/).
The ability to extract or inject heat from/into the ground, is strictly related to the characteristic steady ground temperature at a depth of 8-10m depth compared to the climatic condition, and to its thermal properties. Thanks to heat pumps and heat exchangers (ground coupled heating-cooling systems) it is possible to convert that heat into a suitable temperature for conditioning residential and tertiary building, contributing to reduce greenhouse gas emission and energy dependence on fossil fuels (http://www.heatunderyourfeet.eu/).
The overall aim of ITER is to ensure the sustainability of ground coupled heating-cooling systems and especially the very shallow horizontal ground heat exchangers systems. “Very shallow” means horizontal collector systems or special forms (i.e. helix system), interesting the first 2 m depth from ground level, up to 10 m depth maximum (http://www.thermomap-project.eu/).
Since shallow geothermal energy resource is becoming increasingly important as renewable energy resource, due to its huge potential in providing thermal energy for heating/cooling purposes and thanks to its local availability, manageability and flexibility, the number of installed geothermal systems is expected to continue to rise in the near future.
Then, research and innovation actions in this topic are focused on finding new technical solution, developing emerging technologies and improving heat transfer efficiency of existing systems. There is required, on the one hand, a better knowledge of the thermal properties of the ground and, on the other, the efficient implementation of thermal energy transfer technologies.
Key challenges are:
- to enhance the heat transfer of the ground surrounding the pipes creating thermally enhanced backfilling material (TEBM) suitable for horizontal systems;
- to assess the performance and the environmental impacts of new promising technological solutions as special forms with and without TEBM;
- to monitor the results over time through direct measurements and numerical simulation.
Thermal laboratory measurements performed at FAU University in Erlangen (Germany) and in situ monitoring of existing and duly installed horizontal systems (a test site has been realized in Eltersdorf, near Erlangen) are provided by close cooperation between host institutions and non-academic partners.
ITER project has received funding from the European Union’s Framework Programme for Research and Innovation Horizon 2020 (2014-2020) under the Marie Skłodowska-Curie Grant Agreement No.[661396-ITER].