The increasing scarcity of available land has accelerated the adoption of aquavoltaic systems; however, concerns about their environmental impacts are growing. Specifically, the influence of photovoltaic (PV) modules on water surface wind speed remains inadequately explored. To address this knowledge gap, a three-dimensional numerical model is developed to systematically investigate the effects of module tilt angle, height, incoming wind speed, and wind direction on the relative wind speed over water surface, compared to a baseline case without PV modules. Detailed flow field analyses reveal that the south-facing PV module generates distinct wind flow patterns: under southerly winds, channeling effects enhance near-surface flow, while under northerly winds, competing channeling and blockage effects suppress it. Variations in produce changes of less than 1% in ur, confirming their negligible influence. A critical installation height of h = 1.5 m is identified, above which aerodynamic disturbances become insignificant. Below this threshold, flow disturbances intensify with increasing tilt angle, with peaking at 1.25 under south winds and decreasing to 0.85 under north winds at h = 0.5 m and 80 tilt angle. Additionally, a semi-empirical formula for ur is derived by incorporating the equivalent wind speed into a power-law expression and calibrating its coefficients through regression, achieving estimation errors of less than 4%. Finally, the relationship between ur and the cooling of the PV modules is established, including their impact on the local microclimate. Based on this, the optimal ventilation height is proposed, along with the corresponding variations in water surface evaporation rates and convective heat transfer coefficients caused by changes in wind speed. These findings provide a generalized analytical tool for quantifying PV-induced airflow modifications and support the environmentally informed design of aquavoltaic systems.