Skip to content
PinasKwenta
Menu
Home and utilities

Solar Savings Calculator

What rooftop solar saves each month and when it pays for itself.

Your numbers

Sample numbers are filled in. Tap a box and type yours.

From your installer’s quote
About 4.5 for most of the Philippines
80% is typical
Your bill total ÷ kWh used
The rest goes to the grid
Often near your bill’s generation charge

Results update as you type. Calculate takes you to your result.

Solar savings

You save per month₱5,508.00The system pays for itself in about 4.5 years.

Solar output per month
540 kWh
Used at home
378 kWh
Exported to the grid
162 kWh
You save per month
₱5,508.00
Savings per year
₱66,096.00
Payback
4.5 years
Net gain over 25 years
₱1,352,400.00

An estimate from the numbers you enter. How it’s computed · Change your numbers

You save per month₱5,508.00

How to use this calculator

  1. Enter the system size and installed price from your installer’s quote.
  2. Set your rate, how much solar you’ll use during the day, and the credit your utility gives for exports.

How it’s computed

Monthly output = kWp × peak sun hours × 30 × performance %.

Savings = output used at home × your rate + output exported × net-metering credit.

Payback = system cost ÷ yearly savings. The 25-year figure is savings over a typical panel warranty minus the cost, before maintenance and inverter replacement.

Example

A 5 kWp system costing ₱300,000.00, with 70% used at home:

  • Output: 540 kWh a month.
  • Savings: ₱5,508.00 a month, ₱66,096.00 a year.
  • Payback in about 4.5 years.

Frequently asked questions

What size system do I need?

Divide your monthly kWh by 30, then by your peak sun hours and by 0.8. A home using 400 kWh a month in an area with 4.5 sun hours needs roughly 3.7 kWp to cover it fully.

What are peak sun hours?

The number of hours a day the sun delivers full-strength light. Much of the Philippines averages around 4.5 a day across the year, lower in the rainy season.

Why does the share used at home matter?

Power you use as it’s made replaces power you’d buy at the full rate. Power sent to the grid under net metering earns a lower credit, so homes that use more during the day save more.

Are the sample prices accurate?

Sample figures only. Get the system price and net-metering credit from your installer and your utility; exports are usually credited at about the generation charge, not the full rate.

What about batteries?

This estimate is for grid-tied solar without batteries. Batteries let you use more of your own power at night but add a large cost and need replacing sooner than panels.

This calculator provides estimates for informational purposes only. Actual payroll, taxes, contributions, loan charges, and utility costs may vary depending on your employer, provider, government rules, or specific circumstances.

You may also need

Read the guide