What Size Solar System Do You Need for a ₱5,000 Monthly Bill?
₱5,000 seems to be the magic number. Below it, people shrug and pay. At ₱5,000 — roughly what one aircon running nightly does to a household — the “should we get solar na?” conversation starts. So let’s answer it properly, with September 2026 numbers, not the 2022 numbers most articles are still quoting.
Short version: about 3.1 kWp. Six panels, 16 square meters of roof, ₱110,000–₱173,000 installed, paid back in roughly three years.
Now the receipts.
From pesos to kilowatt-hours
Meralco’s current rate is ₱14.74 per kWh (September 2026). So:
₱5,000 ÷ ₱14.74 ≈ 339 kWh a month, or 11.3 kWh a day.
That’s your consumption. Solar sizing is just working backwards from it.
From kilowatt-hours to panels
The Philippines gets about 4.5 peak sun hours a day, averaged across the year. Real systems also lose around 20% to the inverter, wiring, and heat (panels hate init, ironically). Both go in the denominator:
11.3 kWh ÷ (4.5 × 0.80) ≈ 3.1 kWp
Panels sold here in 2026 are mostly in the 580 W class, so that’s six panels on about 16 m² of roof. Most bungalows and two-storey homes have more than that facing a usable direction. If your roof is busy with vents and antennas, that’s a conversation for the installer’s site visit, not a dealbreaker.
What it costs and what it earns back
Grid-tie installs run ₱35,000–₱55,000 per kWp right now, and small systems land near the top of that range. Budget ₱110,000–₱173,000 for 3.1 kWp.
Against that: offsetting most of a ₱5,000 bill saves around ₱60,000 a year. Payback lands in the 2–3 year zone, which tracks the 3.1-year national average Ember published this year. Panels are warrantied for 25. The arithmetic after year three is the reason your neighbors keep installing.
Before you take this number to an installer
Two honest adjustments. If nobody’s home on weekdays, your daytime solar gets exported instead of used, and Meralco credits exports at only ~₱6/kWh against the ~₱14.74 you avoid by consuming directly. Empty-by-day households often do better sizing at 75% of the full-offset number.
And Metro Manila labor runs 10–15% above provincial quotes. Sakto lang — it’s the same panels, pricier crews.
Your bill probably isn’t exactly ₱5,000, so run your real number through the solar panel calculator, then stress the result in the payback calculator with your actual daytime usage. Then get two or three itemized quotes and see which installer’s math survives contact with yours.