ASCE 7-22 · CHAPTER 29 · SOLAR PV

Solar Panel Wind Loads

Rooftop arrays and ground mounts both fight the wind — uplift at the leading edge, down-force across the field. ASCE 7-22 Chapter 29 sets the approach.

Ch 29ASCE 7-22 SOLAR PROVISIONS
Uplift + Down-forceWIND ACTS BOTH WAYS
Tilt & EdgeDRIVE PEAK ZONES

HOW WIND HITS THE ARRAY

Uplift peaks at the leading edge

Wind sweeping up a low-slope roof accelerates over the first row of tilted panels. The leading edge and array corners see the strongest suction; interior panels are sheltered.

parapet WIND UPLIFT (peak) down-force tilt ω leading edge sheltered interior

WHAT DRIVES THE LOAD

Four things move the pressure

ASCE 7-22 Chapter 29 builds rooftop solar pressures from the array's geometry and position — not a single flat number.

Tilt angle (ω)

Steeper panels catch more wind — uplift and sliding force climb with tilt.

GEOMETRY

Roof zone / edge

Corners and edges see higher suction than the sheltered interior field.

ZONE 1/2/3

Parapet height

A taller parapet reshapes the flow over the roof and shifts panel pressures.

FLOW SHAPE

Array position

Exposed leading rows and isolated arrays draw the strongest edge effects.

EXPOSURE

TWO SYSTEMS, TWO FLOW PATTERNS

Rooftop vs. ground-mount

Where the array sits changes how the wind reaches it — and which ASCE 7-22 provisions govern.

Rooftop arrays

Governed by ASCE 7-22 Chapter 29 solar provisions. Building aerodynamics, roof zone, parapet height and panel tilt all shape the pressure — array edges and corners drive the peaks.

CH 29.4.3 / FIG 29.4-7

Ground mounts

Act like open, elevated structures — wind flows above and below the tilted plane, with no enclosed interior. Tilt, height and row spacing govern uplift and down-force on the racking.

OPEN STRUCTURE · GCpi N/A

THE DESIGN-CRITICAL TAKEAWAY

Attachments & ballast must resist uplift

Wind drives both uplift and down-force on a PV array. Fasteners, racking and ballast must hold the panels down against suction and carry pressure into the structure — sized for the worst case, not the average.

Kd = 0.85DIRECTIONALITY FACTOR
qhVELOCITY PRESSURE AT ROOF HT
Both waysRESIST UPLIFT + DOWN-FORCE

RUN YOUR NUMBERS

Calculate your solar wind loads

Site-specific design pressures for rooftop and ground-mount PV per the latest ASCE 7 (ASCE 7-22).