The indoor temperature difference between photovoltaic (PV) panels and conventional rooftops has become a hot topic in renewable energy circles. At EK SOLAR, we've measured gaps of 4-12°F (2-7°C) across 150+ installations – numbers that impact both energy bills and system efficiency. On hot days, surface temperatures can reach 40-60°C. It provides actionable guidance for optimizing any cooling benefits from solar installations. Solar panels change. Using Lyon as a case study, an international research team has simulated the effects of rooftop photovoltaic (PV) coverage in an urban area at three levels: 25%, 60%, and 100%. 72 °C, while cooling nighttime.