Under the objectives of the “dual carbon” initiative, building-integrated photovoltaic (BIPV) technology has emerged as a pivotal strategy for facilitating the low-carbon transformation of building infrastructure. Nevertheless, the efficacy of BIPV systems is significantly influenced by climate conditions. A comprehensive quantitative analysis quantifying the impact of BIPV on the thermal performance of building envelopes, outdoor microclimates, and energy production across diverse climate zones remains insufficient. This research develops a coupling model grounded in the physical framework of BIPV, incorporating Computational Fluid Dynamics (CFD) and Building Energy Simulation (BES) methodologies to evaluate the effects of PV. Harbin (a severe cold region), Hangzhou (a hot-summer and cold-winter region), and Guangzhou (a hot-summer and warm-winter region) are selected as representative cities. The simulation presumes a consistent surface reflectance and an equivalent albedo of 0.3 for BIPV surfaces. The findings indicate that: (1) BIPV-enabled envelopes exhibit lower temperatures compared to non-BIPV counterparts with identical albedo, resulting in a reduction of outdoor mean radiant temperatures (MRT). In winter, after BIPV installation, peak MRTs in Harbin, Hangzhou, and Guangzhou decrease by 0.62°C, 0.74°C, and 0.74°C, respectively. Correspondingly, the maximum reduction in the Universal Thermal Climate Index (UTCI) reaches 0.21°C, 0.47°C, and 0.46°C. The influence on the average air temperature (AT) is marginal, with decreases not exceeding 0 08°C. (2) After BIPV installation, the daytime UTCI reduction correlates with enhanced solar irradiation, reaching a maximum of -0. 70 ° C during peak isolation around 14 00 in Guangzhou. (3) In different climate zones, solar irradiance and local climate conditions jointly influence PV power generation and building cooling/heating loads. In summer, Harbin experiences high solar irradiance and low cooling demand, achieving 104.1 Wh/m2 of power generation and 257.2 Wh/m2 of energy consumption. This results in an energy self-sufficiency rate of 40.5%, surpassing that of Hangzhou (30.5%) and Guangzhou (19.7%). These results provide foundational insights to support the deployment of BIPV technology across diverse climatic zones.