To promote the utilization of ground-source heat pumps, a new methodology to calculate the low-temperature geothermal potential (LTGP) of a region is presented. The methodology is applicable worldwide, and it considers both closed- and open-loop systems. This new approximation for closed-loops calculates the admissible heat flux exchange with the ground according to an analytical solution of the heat transport equation in porous media. Open-loop systems are calculated as a function of a sustainable removable water flux and the temperature difference between groundwater and a referenced external body. The automated calculation in the setting of a GIS platform has allowed the performance of multilayered 3D mapping of the low-temperature geothermal potential for both types of exploitations considering all of the available information. An example of the application of the methodology in the Metropolitan Area of Barcelona (Spain) is also presented. Finally, a finite element analysis has been performed to quantify the accuracy of the method and the influence of heat advection processes in the LTGP. (C) 2014 Elsevier Ltd. All rights reserved.