Earliest date in the year with a continuous 5‑hour window ≥ 600 W/m² for IR thermography — derived from live VCOM + GPM irradiance APIs and validated against five years of real data from the nearest reference plant.
The plant's own VCOM pyranometers return empty ({"data":{}}) and its G_M0 channel is all‑null. We selected the closest sibling with a live, in‑plane sensor and a multi‑year record. Puente Solar wins decisively — same region, ~21 km away, near‑identical latitude, and a tracker‑mounted pyranometer just like Aguas Claras.
| Reference candidate | Dist. | Lat. | API |
|---|
Distance from Aguas Claras (−33.36°, −70.81°, Región Metropolitana). Lower latitude = lower winter sun, so every alternative is a more conservative proxy.
Real Puente pyranometer profiles on clear days. Near the June solstice the curve never crosses 600 W/m². By early August a clear day clears 600 for 6+ hours; by spring, all day. The dashed line is the IEC 62446‑3 thermography minimum.
Source: GPM · iEnergia tenant · Puente Solar pyranometer (datasource 41252), 15‑min resolution, America/Santiago.
Hours per day at or above 600 W/m² in the plane of the array, every day of August 2025 at Puente. Clear days (tall bars) already exceed 5 h from Aug 7; the gaps are simply cloudy days. The geometry permits it — you only need to pick a clear day.
Bars ≥ 5 h (orange) clear the thermography threshold. Grey bars = overcast days. Red dashed = 5 h target.
Best (clearest) achievable in‑plane window by week across Jul–Oct 2025 at Puente, against the clear‑sky model computed at the Aguas Claras coordinates. The two curves agree — the model is validated by real measurements.
You asked for GHI (global horizontal). But IEC 62446‑3 — the IR inspection standard — specifies irradiance in the plane of the modules. On a tracker plant the array follows the sun, so in‑plane irradiance is far higher and flatter than horizontal GHI. That single distinction moves the date by six weeks.
What the thermal camera actually sees on the modules, and what Puente's pyranometer measures. Backed by 5 years of real data. This is the operative answer for an IEC‑compliant survey.
If your inspection protocol strictly mandates global horizontal irradiance, the clear‑sky model at the Aguas Claras coordinates first sustains 5 h ≥600 around this date (window ≈ 11:00–16:20 local).