The plant is online and irradiance sensors show usable resource, but delivered power is lower than the irradiance should support. With grid curtailment, output sits flat or at a controlled level below available power, so check plant setpoints, dispatch signals and curtailment flags first. With an inverter voltage floor, inverter DC voltage stays at its minimum limit while the IV-derived Vmp is lower, mostly in hot periods or when reactive power demand is high. Tracker wind stow causes repeated output dips in gusty weather; compare tracker stow logs with high-frequency gust data. Snow accumulation causes an abrupt drop after snowfall and a gradual recovery during melt, and it can make string currents uneven; confirm it with weather data and camera or drone images. Zero production while irradiance is sufficient points to an outage or a communication loss rather than any of these losses. Before blaming one cause, rule out outages, curtailment, clipping, soiling and sensor faults, because these losses can look like each other in monthly reviews.
<!-- review notes
observed_asc1 drafted · lead DC voltage pinned at minimum
Points to an inverter voltage floor. One monitored system showed a horizontal line at the lower MPPT window boundary, and only at low irradiance.
sec=h6 h=1a2c2578fa31sec=2.1 h=533a89670acac2 verified · fact Operating voltage above Vmp
Supports a voltage-floor event when the measured operating voltage stays above the IV-derived Vmp and the operating power is below the IV-derived Pmp.
sec=h6 h=1a2c2578fa31sec=h4 h=7023830f6e10verified by: joshuahamsaverified on: 2026-10-20
c3 verified · fact Flat output below available power
Signature of grid curtailment. Inverter and tracker availability can look normal.
sec=h4 h=576525a653a1sec=h6 h=08e6be358742verified by: joshuahamsaverified on: 2026-10-20
c4 verified · fact Output dip during stow
Intermittent and correlated with weather. Rows may enter stow repeatedly in gusty weather.
sec=h4 h=65b80c7f6952sec=h6 h=733de3a75bd0verified by: joshuahamsaverified on: 2026-10-20review note: support check: partial - Intermittent, weather-correlated dips during gusty weather are stated, but the specific gust-above-stow-threshold signal is only implied (threshold exceedance is mentioned, not a gust-vs-threshold condition at the same time exactly).
c5 verified · fact Snow-aligned production residual
Drop is abrupt after snowfall and recovery is gradual during melt or slide-off.
sec=h4 h=0f32a669be34sec=h6 h=0935b66311acsec=h2 h=cf13e86d6896verified by: joshuahamsaverified on: 2026-10-20review note: support check: partial - Abrupt drop after snowfall and gradual recovery are stated, but the cold ambient temperature slowing snow clearing is not stated.
c6 verified · fact Snow cover in imagery
Camera, drone or field observations show snow covering the modules.
sec=h6 h=0935b66311acsec=h2 h=cf13e86d6896verified by: joshuahamsaverified on: 2026-10-20
c7 verified · fact Zero power with irradiance
Indicates an outage or downtime. One monitoring rule flags zero production when GHI is at least 100 W/m2.
tbl=11.r3 h=5690bc5ac9cdsec=1.2.2 h=362882b92bf7verified by: joshuahamsaverified on: 2026-10-20
typical_power_lossc8 drafted · lead nominal 1.2 PERCENT
Conditions: Average energy loss from inverter voltage flooring in summer 2025 at a 100 MW California PV plant
sec=h5 h=43c9f30df704c9 verified · fact ≤ 4 PERCENT
Conditions: Extra annual production loss from gust-driven tracker stow, compared with models that use only hourly wind data
sec=h5 h=3f9ef9562906verified by: joshuahamsaverified on: 2026-10-20
presents_as c7presents_as c9presents_as c7presents_as c7presents_as c3