Page 64 - Analysis and Design of Energy Geostructures

34 Analysis and Design of Energy Geostructures

Figure 2.7 Possible pipe locations in energy tunnels, walls and slabs, considering a U-shaped pipe
configuration located: (A) close to both sides, (B) close to the airside, (C) close to the groundside
and (D) close to the groundside with an insulated airside.

2.2.5 Advantages involved with energy geostructures
Similar to other technologies harvesting renewable energy, such as conventional geo-
thermal systems, energy geostructures are an environment-friendly technology that
reduces the need of fossil energy sources and hence the greenhouse gas emissions. For
this reason the use of energy geostructures promotes and complies with national and
international initiatives, policies, regulations and agreements. Furthermore, energy
geostructures may be applied with other technologies harvesting renewable energies to
form highly efficient systems.
In contrast to conventional shallow geothermal systems, the earth-contact elements
that characterise energy geostructures and serve as heat exchangers are already required
for structural reasons and need not to be constructed separately (Brandl, 2006). This
fact involves savings related to the construction process that should be undertaken in a
separate realisation of geostructures and geothermal heat exchangers.
Another key difference between energy geostructures and other conventional
closed-loop geothermal systems is that concrete typically has more favourable thermal
properties than the filling materials (e.g. bentonite) of the other geothermal technolo-
gies. This feature makes the heat exchange more favourable in the former case