This study provides a comprehensive analysis of the fire hazards associated with Building-Integrated Photovoltaics (BIPV), using Aluminum Composite Panels (ACP) as a benchmark. Large-scale fire tests, modified from ISO 13785-1, were conducted on vertically installed BIPV modules to observe their fire behavior under conditions simulating a severe fire. The experimental process involved measuring key fire performance indicators, leading to the identification of a cascading failure mechanism. The BIPV modules demonstrated a peak Heat Release Rate (HRR) up to hi times higher (max. 898 kW) and smoke production nearly 10 times greater than the ACP baseline. The analysis reveals a distinct, multi-stage failure sequence that defines the systemic fire hazard of BIPV. Initially, a phenomenon strongly indicative of a chimney effect within the rear air cavity accelerates concealed fire spread. This rapid heating induces thermal stress, leading to extensive specimen damage termed cracking. This cracking event acts as a critical turning point, triggering a rapid release of trapped pyrolyzates and driving the fire to its peak intensity. This chain of events constitutes a unique hazard signature not observed in conventional cladding. The findings conclude that the fire risk of BIPV is a systemic issue, challenging the adequacy of component-level testing and highlighting the need for safety standards that assess the façade as a complete assembly.