CAISO's published "demand" is really net load: actual consumption minus the output of ~19 GW of behind-the-meter rooftop solar that nobody meters in real time. This tracker models that invisible fleet — 2 million systems across 1,500+ ZIP codes — from clear-sky physics and live cloud cover, and reconstructs true demand = CAISO demand + invisible solar.
| Time | CAISO net (MW) | Invisible solar (MW) | True demand (MW) |
|---|
Fleet: every NEM/NBT interconnected PV system in PG&E, SCE & SDG&E territory (the CAISO IOU footprint) from the CPUC / California DGStats interconnection dataset — ~2 million systems, grouped by ZIP and then by roof orientation (22.5° azimuth × 10° tilt bins), each bin modeled separately. Collapsing a ZIP to one average angle would bias it: output is concave in azimuth, so a neighbourhood split east/west is not a south-facing neighbourhood, and averaging first overstates the midday peak by ~3% and sharpens it. Systems reporting azimuth 0° with tilt 0° are the dataset's unreported-data sentinel (~10% of capacity), not flat north-facing arrays, so they inherit their ZIP's observed orientation mix instead of being averaged in as real. Production model: per-ZIP clear-sky irradiance (pvlib Ineichen, elevation-aware) attenuated by live NWP cloud/irradiance (Open-Meteo), Erbs decomposition, Hay-Davies transposition, cell-temperature correction, and a fleet loss factor. Demand: CAISO Today's Outlook, 5-minute. Estimates carry a ±15% band — this is a model, not a meter; EIA publishes the official (monthly, lagged) estimate. Excludes non-CAISO utilities (LADWP, SMUD…). Cloud data ahead of the current time is a forecast (dashed).
Part of eshansingh.xyz · like the battery locator and CA grid map, this page refreshes its data automatically through the day.