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NAME

r.green.gshp.theoretical - Calculate the Ground Source Heat Pump potential

KEYWORDS

raster, geothermal, renewable energy

SYNOPSIS

r.green.gshp.theoretical
r.green.gshp.theoretical --help
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] [--help] [--verbose] [--quiet] [--ui]

Flags:

-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
--ui
Force launching GUI dialog

Parameters:

ground_conductivity=name [required]
Raster with depth-averaged ground thermal conductivity λ [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
Options: 0-365
Default: 180.
power_value=double
Power value in kW
Default: nan
ground_capacity_raster=name
Raster with depth-averaged ground thermal capacity ρc [MJ m-3 K-1]
ground_capacity_value=double
Value with depth-averaged ground thermal capacity ρc [MJ m-3 K-1]
Default: 2.5
ground_temp_raster=name
Raster with the initial ground temperature T0 [°C]
ground_temp_value=double
Value with the initial ground temperature T0 [°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 [°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]

Table of contents

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:
Pgshp=8*(T0 - Tlim) λ L t'c/(-0.619 t'c log(u's)-0.455 t'c-1.619+4 π Rb)

where
T0 is the undisturbed ground temperature (°C),
Tlim 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 ,
Rb 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 \

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

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

Last changed: $Date: 2018-11-13 07:59:33 +0100 (Tue, 13 Nov 2018) $

SOURCE CODE

Available at: r.green.gshp.theoretical source code (history)


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