DESCRIPTION

r.green.gshp.theoretical assess the shallow geothermal potential defined as the thermal power exchanged by a Borehole Heat Exchanger of a certain depth. This potential depends on the thermal properties of the ground and the plant features. This module returns two output raster maps with the the energy potential (MWh/year) and the power potential (W). In this module the output is the theoretical maximum energy that can be converted in the ideal case without considering the financial and spatial constraints.

NOTES

The required inputs are the the thermal conductivity. If not specific values are indicated, reference values have been assumed for the ground features and the plant.

EXPLANATION

r.green.gshp.theoretical calculates the potential of shallow geothermal energy by means of and empirical relationship proposed by Casasso et al. (2016) as:

P_gshp=8*(T₀ - T_lim) λ L t'_c/(-0.619 t'_c log(u'_s)-0.455 t'_c-1.619+4 π R_b)

where
T₀ is the undisturbed ground temperature (°C),
T_lim the threshold temperature of the heat carrier fluid setting to 2°C,
λ is the the thermal conductivity of the ground (W/(mK)),
L the borehole length (m),
t'_c is is the operating time ratio ,
u'_s is a parameter depending on the simulaion time and the borehole radius ,
R_b is the thermal resistance (K/W)

EXAMPLES

This example is based on the case-study of the EUSALP region, located in Europe and covering part of Italian, Slovenian, Austrian, German, Swiss and France territories. The data can be downloades at the following repositories EUSALP dataset .

r.green.gshp.theoretical \
    ground_conductivity=conductivity \
    heating_season_raster=season_heating \
    ground_temp_raster=ground_temperature \
    ground_capacity_value=2.3 \
    power=gpot_power \
    energy=gpot_energy \

AUTHORS

Pietro Zambelli (Eurac Research, Bolzano, Italy), Tested by and manual written by Giulia Garegnani

REFERENCES

Alessandro Casasso, Rajandrea Sethi, 2016,
"G.POT: A quantitative method for the assessment and mapping of the shallow geothermal potential"
Energy 106, p 765 --
http://dx.doi.org/10.1016/j.energy.2016.03.091