Wind uplift is a governing structural design load for rooftop solar PV. When wind flows across the top of a tilted panel, velocity increases and pressure decreases relative to the more sheltered underside, creating a net upward suction force. This uplift acts opposite to gravity loads, potentially exceeding the dead weight of the array and requiring positive anchorage or adequate ballast.
Peak uplift pressures occur at array corners and edges, and at roof edge and corner zones where ambient wind flow separates from the building surface. Structural engineers calculate design uplift using Eurocode 1 Part 1-4 wind pressure coefficients adjusted for array geometry, tilt, and site-specific wind speed. These calculations inform both fixing design and ballast weight requirements.