When the grid was down each day. Stack lets you see if outages cluster at the same time of day (scheduled) or jump around (ad-hoc). Detection: ac_input_voltage < 50 V across consecutive 5-min samples — sub-minute flickers are missed by design. Hatched grey means no data from BLE or cloud (both inverter Wi-Fi and Mac were offline that window).

Per-period reconciliation: grid units from local data vs LESCO bills. Diff = (Meter A + Meter B) − Grid (data); positive means bills are higher than what we recorded. Read-window drift checks the nearby edge days when LESCO's actual read window does not line up with the anchor day.