With sharp climate goals to be climate neutral by 2045, Sweden needs to rapidly change the present energy system. The Swedish government has assigned Gotland as a pilot area for the energy transition, due to its geographical constrains as an island, and because of the major structural changes planned for Gotland’s energy supply and industrial establishment. These changes create the opportunity to build a more flexible, efficient, and robust energy system. To support the transition, IVL Swedish Environmental Research institute has initiated the GOT Heat project. This thesis contributes to the GOT Heat project by developing a GIS model that represent the heat sector of Gotland. The model has been developed in parallel with a TIMES model. The purpose of the GIS model is to be used as a heat atlas and to support the TIMES model of Gotland’s energy system by spatial visualization and knowledge. The GIS model was successfully developed and utilized to enhance the representation of Gotland’s energy system within the TIMES model. Data from Boverket, Lantmäteriet, Energimyndigheten and companies has been collected, processed for the development of the GIS model. The incorporation of spatial knowledge and visualization of the heat sector through the GIS model is expected to improve the overall outcomes of the TIMES model. The heat atlas also proved to be a valuable support tool, enabling the visualization of excess heat potentials within the heat sector. This visualization provides insights into potential opportunities for industrial and sector coupling, which would lead to more efficient utilization of excess heat.