Stressor
Heavy snowfall
- ID
stressor:snow-load- IRI
https://solarlattice.org/kb/stressor/snow-load- Status
- active
- Also known as
- heavy snow, snow load, snow loading
Heavy snowfall loads PV arrays with snow mass and also covers modules so irradiance cannot reach the cells, which costs energy during winter. Under the weight of snow, modules can bend until the glass and cells crack. Ice dams can tear off the bottom frame, and racks that were not engineered for the load can collapse. Wet, wind-packed or refrozen snow is much denser than fresh snow. Freeze-thaw cycles in spring and drifts near walls or between rows can build loads high enough to burst or deform frames. Snow lying on the modules and snow sliding off unevenly cause snow accumulation yield losses and uneven current between strings. Mounds of shed snow can block the lower edge of the modules and stop trackers from moving. Cold makes cells more brittle, so cell cracks are more likely at snowy sites. Large-format modules and corner-clamped modules are especially vulnerable. Exposure can be reduced with steeper tilt, high ground clearance, tracker snow-stow strategies, and bifacial or frameless modules that shed snow faster. Robust modules with thicker glass and well-engineered racking also help. After winter, inspect the array visually and thermally image a subset of modules. Where snow sticks heavily, remove it with a turbo-fan rather than a shovel.
<!-- review notes
- sentence 5: support check: partial - Cold-induced brittleness and cracking at snowy sites is stated, and large-format modules are noted as not reinforced, but corner-clamped modules were only noted as damaged, not stated as especially cracking-vulnerable.
- sentence 7: support check: partial - Post-winter visual inspection with thermal imaging of a subset and turbo-fan snow removal are stated, but the passages do not tie turbo-fan removal specifically to heavily stuck snow, and say removal is generally not recommended.
-->
Claims
typical_power_loss
c1 verified · fact
0–2 PERCENT
Conditions: Annual average performance reduction from snow accumulation in southern US states
verified by: joshuahamsaverified on: 2026-10-20review note: support check: partial - The 0%–2% figure for southern states is stated, but the statement labels it 'heavy snowfall' typical loss, which the passage assigns to heavy-snow places (10–16%).; possible conflict with c3 (same source; check the conditions); reviewer: the compiler-flagged conflict is a different scenario or technology, not disagreement
c2 verified · fact
2–4 PERCENT
Conditions: Annual average performance reduction from snow accumulation in arid US states such as Colorado
verified by: joshuahamsaverified on: 2026-10-20review note: support check: partial - 2%–4% in arid states like Colorado is stated, but it is not described as heavy snowfall.; possible conflict with c3 (same source; check the conditions); reviewer: the compiler-flagged conflict is a different scenario or technology, not disagreement
c3 verified · fact
10–16 PERCENT
Conditions: Annual average performance reduction in heavy-snowfall US states such as Michigan, Wisconsin and Maine
verified by: joshuahamsaverified on: 2026-10-20review note: possible conflict with c1 (same source; check the conditions); possible conflict with c2 (same source; check the conditions); reviewer: the compiler-flagged conflict is a different scenario or technology, not disagreement
c4 verified · fact
≤ 10 PERCENT
Conditions: Yearly snow losses for standard framed modules at latitudes above 60°N in Sweden (most often)
verified by: joshuahamsaverified on: 2026-10-20review note: support check: partial - The passage says losses are most often less than 10% yearly, an upper bound, not a typical loss value of 'up to 10%' under heavy snowfall.; possible conflict with c5 (same source; check the conditions); possible conflict with c6 (same source; check the conditions); possible conflict with c7 (same source; check the conditions); possible conflict with c9 (same source; check the conditions)
c5 verified · fact
nominal 18 PERCENT
Conditions: Measured annual production loss, modules at 0° tilt, Sierra Mountains, USA
verified by: joshuahamsaverified on: 2026-10-20review note: possible conflict with c4 (same source; check the conditions); possible conflict with c6 (same source; check the conditions); possible conflict with c7 (same source; check the conditions); possible conflict with c8 (same source; check the conditions); possible conflict with c9 (same source; check the conditions); reviewer: the compiler-flagged conflict is a different scenario or technology, not disagreement
c6 verified · fact
nominal 15 PERCENT
Conditions: Measured annual production loss, modules at 24° tilt, Sierra Mountains, USA
verified by: joshuahamsaverified on: 2026-10-20review note: possible conflict with c4 (same source; check the conditions); possible conflict with c5 (same source; check the conditions); possible conflict with c7 (same source; check the conditions); possible conflict with c8 (same source; check the conditions); possible conflict with c9 (same source; check the conditions); reviewer: the compiler-flagged conflict is a different scenario or technology, not disagreement
c7 verified · fact
nominal 12 PERCENT
Conditions: Measured annual production loss, modules at 39° tilt, Sierra Mountains, USA
verified by: joshuahamsaverified on: 2026-10-20review note: possible conflict with c4 (same source; check the conditions); possible conflict with c5 (same source; check the conditions); possible conflict with c6 (same source; check the conditions); possible conflict with c8 (same source; check the conditions); possible conflict with c9 (same source; check the conditions); reviewer: the compiler-flagged conflict is a different scenario or technology, not disagreement
c8 verified · fact
0.3–2.7 PERCENT
Conditions: Annual snow-cover losses, frameless modules at 28° tilt, grid-connected system in Bavaria, Germany
verified by: joshuahamsaverified on: 2026-10-20review note: support check: partial - The 0.3–2.7% annual loss for frameless 28° modules in Bavaria is stated, but it is not described as heavy snowfall.; possible conflict with c5 (same source; check the conditions); possible conflict with c6 (same source; check the conditions); possible conflict with c7 (same source; check the conditions); possible conflict with c9 (same source; check the conditions); reviewer: the compiler-flagged conflict is a different scenario or technology, not disagreement
c9 verified · fact
nominal 23 PERCENT
Conditions: Monthly loss from snow cover in January 2017, Konya, Turkey, compared with daily-cleaned modules
Daily losses there could approach 100%.
verified by: joshuahamsaverified on: 2026-10-20review note: possible conflict with c4 (same source; check the conditions); possible conflict with c5 (same source; check the conditions); possible conflict with c6 (same source; check the conditions); possible conflict with c7 (same source; check the conditions); possible conflict with c8 (same source; check the conditions); reviewer: the compiler-flagged conflict is a different scenario or technology, not disagreement
Referenced by
Data