The short version: five months in, the array covers roughly two-thirds to three-quarters of the house and is tracking to a ~3.5-year payback. What surprised me wasn't the generation — it was how much the timing of PHEV charging swings the bill (Dec–Mar EV-charging days import ~₱12/day more than non-EV days). If you're sizing a system here, the lever that generalizes from this single-site data is load timing, not panel count. Once it was running I also took it through Meralco net metering — that paperwork is its own story: Net Metering Journey in General Trias.
Headline numbers
Annual bill cut
₱115,973
~69% of pre-solar bill
Simple payback
~3.5 yrs
on ₱400k turnkey
Year-1 generation
~7,663 kWh
~21 kWh/day baseline
CO₂ avoided
~4.7 t/yr
≈216 trees · 22,600 km
What the data shows
Self-sufficiency climbed from 54% in December to a peak of 76% in March, then dipped to 68% in April when household consumption jumped sharply (avg daily load rose from ~29 to ~39 kWh). The April surge is not vehicle charging — the PHEV was off the road all month — it is the second AC unit running nearly 24/7 during summer break.
No equipment fault is visible. Peak PV reached 5.4 kW (68% of inverter capacity), there is zero clipping, and battery round-trip efficiency stays in the healthy 94–98% band. One day worth flagging: 2026-01-02 generated only 4.7 kWh against an expected ~17.8 kWh — confirm against weather/inverter logs.
For Dec–Mar, the highest-impact lever is shifting PHEV charging earlier into the solar window. For April specifically — and for future summer-break stretches — the highest-impact lever shifts to AC management. See recommendations →
Monthly bill impact
Month
Bill without solar
Net savings
Dec 2025
₱13,974
₱7,589
Jan 2026
₱12,459
₱7,564
Feb 2026
₱11,531
₱9,160
Mar 2026
₱13,222
₱11,166
Apr 2026
₱17,565
₱12,181
April's "without solar" bill is the highest because household load was ~39 kWh/day. Even so, net savings hit a record ₱12,181 — solar is doing more work in absolute terms when consumption is higher.
Disclaimer: the report is AI-assisted. While the underlying data comes from the inverter export, the narrative analysis, recommendations, projections, and financial interpretation may contain inaccuracies. Verify critical findings against your own records, manufacturer specs, or a qualified solar professional before acting on them.
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