Page 64 - European Energy Innovation - Summer 2016 publication
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64  Summer 2016 European Energy Innovation


for the development of shallow
geothermal energy

The annual consumption                   associated with fossil fuel and nuclear  design. In thermoactive structures,
            of energy in the world is    power, while it can be developed         heat exchangers are integrated in
            continuously rising, driven  locally without impact on the landscape  the elements of the structure that
            by increases in population,  and with less land consumption and       interface with the ground, such as
progressive urbanisation, etc. Climate   output fluctuations than solar, wind      foundations, tunnels and diaphragm
change mitigation and adaptation are     or hydro-electrical power. The COST      walls. This technique is also particularly
also challenges for the near future.     ACTION TU1405 GABI (shallow              attractive because of the inherent
In this context, the development         Geothermal Applications for Buildings    cost savings involved in combining a
of local sources of energy with low      and Infrastructure) was launched in      required structural component with
environmental impact is more and         2015 with the objective to build a new   the harvesting of geothermal energy.
more necessary. Geothermal energy        European network of researchers and      Based on multidisciplinary approaches,
can play a significant role among         engineers to address the challenges      this group has the ambition to develop
renewable energy resources. It has       of thermoactive geostructures in         collective understanding, share
none of the environmental risks          terms of thermal and mechanical          techniques, facilities and data, and work
                                                                                  jointly in disseminating the obtained
Heat transfer pipes in a pile reinforcement cage                                  results across Europe.

                                                                                  Shallow geothermal energy is
                                                                                  considered as a domestic resource,
                                                                                  which contributes to fulfilling the
                                                                                  energy demand both by electrical
                                                                                  power generation and direct-heat
                                                                                  uses. This technology only requires a
                                                                                  generally constant ground temperature
                                                                                  over the year. Despite seasonal
                                                                                  fluctuations, this is satisfied in most of
                                                                                  continental Europe, where the ground
                                                                                  temperature at depths higher than 5-8
                                                                                  m typically varies between 8°C and
                                                                                  16°C, but remains constant, down to
                                                                                  approximately 50 m. In such conditions,
                                                                                  the ground operates as heat source
                                                                                  supplying warmth to buildings during
                                                                                  winter, whilst functioning as heat
                                                                                  sink during summer when cooling is

                                                                                  For shallow geothermal systems,
                                                                                  since the temperature differential is
                                                                                  relatively small, just a few degrees, a
                                                                                  heat pump is needed, forming what are
                                                                                  known as Ground Source Heat Pump
                                                                                  systems (GSHP). In such applications
                                                                                  the ground acts as heat exchanger
                                                                                  and storage medium rather than heat
                                                                                  source. Among shallow geothermal

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