The short version: seven months in, the array covers roughly two-thirds to three-quarters of the house and is tracking to a ~3.1-year payback. The biggest lever on the bill is the timing of PHEV charging: charging days pull ~24 kWh from the grid versus ~9 kWh otherwise, because the car currently charges in the late afternoon and evening instead of the midday solar window. If you're sizing a system here, the variable 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
₱131,445
~68% of pre-solar bill
Simple payback
~3.1 yrs
on ₱400k turnkey
Year-1 generation
~8,210 kWh
~22.5 kWh/day baseline
CO₂ avoided
~5.2 t/yr
≈237 trees · 24,800 km
What the data shows
Self-sufficiency climbed from 54% in December to a peak of 77% in March, eased to ~70% across April and May as household consumption rose (avg daily load went from ~29 to ~39 kWh), then dropped to ~60% in June as the wet season arrived. June generation fell ~16% (from ~27.8 to ~23.4 kWh/day) while load held steady, so grid import climbed to ~462 kWh — the highest month yet. This is the expected seasonal turn for a tropical site, not a system problem.
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 (~96% in June). The worst day remains 2026-01-02, which generated only 4.7 kWh — about 74% below baseline, an overcast wet-season day rather than a fault; June's low-generation days trace to the same wet-season cloud.
The highest-impact lever is moving PHEV charging into the midday solar window (09:00–14:00): it currently lands in the late afternoon and evening, when it draws straight from the grid and more than doubles daily import. See recommendations →
Monthly bill impact
Month
Bill without solar
Net savings
Dec 2025
₱13,424
₱7,291
Jan 2026
₱11,736
₱7,039
Feb 2026
₱10,609
₱8,420
Mar 2026
₱12,464
₱10,520
Apr 2026
₱17,542
₱12,165
May 2026
₱18,633
₱13,162
Jun 2026
₱18,539
₱11,144
Net savings peaked in May at ₱13,162, then eased to ₱11,144 in June even though the import rate rose to ₱16.10/kWh — the wet-season generation dip pushed more load onto the grid. Each month is billed at the rate that applied then (rates climbed from ₱14.41 in December to ₱16.10 in June); the ~₱131k annual figure is projected at today's rate.
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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