The viability of installing rooftop solar photovoltaic (PV) systems in Sweden's Gävle Municipality is investigated in this thesis. We carefully studied and modeled the region using Geographic Information Systems (GIS) and LiDAR data to determine the best places to deploy solar panels. In addition to this technical study, a thorough assessment of recent literature is included to enhance our knowledge of the most recent advancements in solar technology and application approaches. The research uses a dual methodology. Precise, quantitative 3D models of the cityscape evaluate potential locations for installations in order to optimize energy production. The study uses a qualitative synthesis of information from industry publications, policy documents, and scientific articles to contextualize our quantitative data in relation to the advancement of solar technology worldwide.  Significant findings emerge from three scenarios examined, with Scenario C focusing on realistic adoption rates. Unlike the more optimistic Scenarios A and B, Scenario C considers variable installation rates based on building types—50% of suitable roof areas for industrial buildings and 25% for residential and community buildings. This scenario provides a conservative yet realistic estimate of Gävle’s solar potential, projecting an annual generation of approximately 200 GWh. This represents a substantial contribution towards the municipality's energy needs but also highlights the practical constraints affecting solar adoption. By presenting a nuanced view of possible outcomes under varying conditions, this thesis underscores the viability of solar energy in urban planning and provides a pragmatic framework that other municipalities could replicate to enhance their sustainable energy portfolios.