r.green.gshp.theoretical

Calculate the Ground Source Heat Pump potential

Command linePython (grass.script)

r.green.gshp.theoretical [-d] ground_conductivity=name [heating_season_raster=name] [heating_season_value=double] [power_value=double] [ground_capacity_raster=name] [ground_capacity_value=double] [ground_temp_raster=name] [ground_temp_value=double] [borehole_radius=double] [borehole_resistence=double] [borehole_length=double] [pipe_radius=double] [number_pipes=integer] [grout_conductivity=double] [fluid_limit_temperature=double] [lifetime=integer] power=name energy=name [length=name] [--overwrite] [--verbose] [--quiet] [--qq] [--ui]

Example:

r.green.gshp.theoretical ground_conductivity=name power=name energy=name

grass.script.run_command("r.green.gshp.theoretical", ground_conductivity, heating_season_raster=None, heating_season_value=180., power_value=nan, ground_capacity_raster=None, ground_capacity_value=2.5, ground_temp_raster=None, ground_temp_value=10., borehole_radius=0.075, borehole_resistence=nan, borehole_length=100, pipe_radius=0.016, number_pipes=4, grout_conductivity=2, fluid_limit_temperature=-2, lifetime=50, power, energy, length=None, flags=None, overwrite=False, verbose=False, quiet=False, superquiet=False)

Example:

gs.run_command("r.green.gshp.theoretical", ground_conductivity="name", power="name", energy="name")

Parameters

Command linePython (grass.script)

ground_conductivity=name [required]
    Raster with depth-averaged ground thermal conductivity lambda [W m-1 K-1]
heating_season_raster=name
    Raster with the Heating Season [0-365] days
heating_season_value=double
    Heating Season [0-365] days
    Allowed values: 0-365
    Default: 180.
power_value=double
    Power value in kW
    Default: nan
ground_capacity_raster=name
    Raster with depth-averaged ground thermal capacity rho_c [MJ m-3 K-1]
ground_capacity_value=double
    Value with depth-averaged ground thermal capacity rho_c [MJ m-3 K-1]
    Default: 2.5
ground_temp_raster=name
    Raster with the initial ground temperature T0 [degrees C]
ground_temp_value=double
    Value with the initial ground temperature T0 [degrees C]
    Default: 10.
borehole_radius=double
    Borehole radius [m]
    Default: 0.075
borehole_resistence=double
    Borehole thermal resistence [m K W-1]
    Default: nan
borehole_length=double
    Borehole length [m]
    Default: 100
pipe_radius=double
    Pipe radius [m]
    Default: 0.016
number_pipes=integer
    Number of pipes in the borehole
    Default: 4
grout_conductivity=double
    Thermal conductivity of the borehole filling (geothermal grout) [W m-1 K-1]
    Default: 2
fluid_limit_temperature=double
    Minimum or maximum fluid temperature [degrees C]
    Default: -2
lifetime=integer
    Simulated lifetime of the plant [years]
    Default: 50
power=name [required]
    Name of output raster map with the geothermal power potential [W]
energy=name [required]
    Name of output raster map with the geothermal energy potential [MWh]
length=name
    Name of output raster map with the geothermal length of the BHE [m]
-d
    Debug with intermediate maps
--overwrite
    Allow output files to overwrite existing files
--help
    Print usage summary
--verbose
    Verbose module output
--quiet
    Quiet module output
--qq
    Very quiet module output
--ui
    Force launching GUI dialog

ground_conductivity : str, required
    Raster with depth-averaged ground thermal conductivity lambda [W m-1 K-1]
    Used as: input, raster, name
heating_season_raster : str, optional
    Raster with the Heating Season [0-365] days
    Used as: input, raster, name
heating_season_value : float, optional
    Heating Season [0-365] days
    Used as: double
    Allowed values: 0-365
    Default: 180.
power_value : float, optional
    Power value in kW
    Used as: double
    Default: nan
ground_capacity_raster : str, optional
    Raster with depth-averaged ground thermal capacity rho_c [MJ m-3 K-1]
    Used as: input, raster, name
ground_capacity_value : float, optional
    Value with depth-averaged ground thermal capacity rho_c [MJ m-3 K-1]
    Used as: double
    Default: 2.5
ground_temp_raster : str, optional
    Raster with the initial ground temperature T0 [degrees C]
    Used as: input, raster, name
ground_temp_value : float, optional
    Value with the initial ground temperature T0 [degrees C]
    Used as: double
    Default: 10.
borehole_radius : float, optional
    Borehole radius [m]
    Used as: double
    Default: 0.075
borehole_resistence : float, optional
    Borehole thermal resistence [m K W-1]
    Used as: double
    Default: nan
borehole_length : float, optional
    Borehole length [m]
    Used as: double
    Default: 100
pipe_radius : float, optional
    Pipe radius [m]
    Used as: double
    Default: 0.016
number_pipes : int, optional
    Number of pipes in the borehole
    Used as: integer
    Default: 4
grout_conductivity : float, optional
    Thermal conductivity of the borehole filling (geothermal grout) [W m-1 K-1]
    Used as: double
    Default: 2
fluid_limit_temperature : float, optional
    Minimum or maximum fluid temperature [degrees C]
    Used as: double
    Default: -2
lifetime : int, optional
    Simulated lifetime of the plant [years]
    Used as: integer
    Default: 50
power : str, required
    Name of output raster map with the geothermal power potential [W]
    Used as: output, raster, name
energy : str, required
    Name of output raster map with the geothermal energy potential [MWh]
    Used as: output, raster, name
length : str, optional
    Name of output raster map with the geothermal length of the BHE [m]
    Used as: output, raster, name
flags : str, optional
    Allowed values: d
    d
        Debug with intermediate maps
overwrite: bool, optional
    Allow output files to overwrite existing files
    Default: False
verbose: bool, optional
    Verbose module output
    Default: False
quiet: bool, optional
    Quiet module output
    Default: False
superquiet: bool, optional
    Very quiet module output
    Default: False

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 \

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 --
https://doi.org/10.1016/j.energy.2016.03.091

SEE ALSO

r.green.hydro.technical, r.green.hydro.technical

AUTHORS

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

SOURCE CODE

Available at: r.green.gshp.theoretical source code (history)
Latest change: Friday Feb 21 12:27:42 2025 in commit 8fce680