Thinking About Rooftop Solar? Read This First

Paying around ₱8,000 a month for electricity? Rooftop solar can help lower that bill, but it will not automatically make it disappear.

The biggest misconception is: “May solar na, wala nang bill.” Not always.

Solar reduces the electricity you buy from the grid. How much you save depends mainly on when you use electricity.

Start with your bill. Check your last 12 months of electric bills and look at kilowatt-hours or kWh, not just the peso amount. A home paying ₱2,000 to ₱3,000 a month may need around 2 to 3 kW of solar. A ₱4,000 to ₱7,000 bill may point to 4 to 5 kW. A ₱8,000 to ₱12,000 bill may need 6 to 8 kW. These are only rough guides. Actual sizing still depends on your roof, shading, budget, and usage pattern.

The key is your household load.

Your refrigerator, Wi-Fi router, CCTV, water dispenser, and standby appliances run day and night. Solar works best when you also use power during the day: fans, computers, washing machine, water pump, rice cooker, daytime aircon, or work-from-home equipment.

At night, solar panels stop producing. Aircon from 8 PM to 6 AM, lights, TV, and other evening appliances are not directly powered by ordinary solar panels unless you have batteries.

That is why two homes with the same bill can get very different savings. A home with people using power during the day can use more solar directly. A home that is empty all day may still buy much of its electricity at night.

For many homes, a well-designed solar system can reduce the bill by around 40% to 80%. But a zero bill should not be the default expectation. It usually requires the right system size, strong daytime use, net metering, and sometimes batteries.

Batteries are useful, but expensive. They make sense if your area has frequent brownouts, if important appliances must stay on during outages, or if most of your power use happens at night. But if your goal is mainly to lower the bill, batteries can slow down the payback and raise total project cost by 50% to 100%.

Before signing, check your roof. Is it shaded? Is it strong enough? Will it need repair in the next 5 to 10 years? Is your electrical system ready? If the roof needs major repair, fix it first.

Work with a DOE-accredited solar PV installer or service provider. Get at least three quotations. Compare the panel brand, inverter, warranties, workmanship, after-sales service, net-metering assistance, and estimated annual production—not just the price.

Then run the numbers. A 3-kW system may cost around ₱150,000 to ₱220,000. A 5-kW system may cost ₱250,000 to ₱400,000. An 8-kW system may cost ₱400,000 to ₱650,000.

If paid in cash, payback may be around 4 to 7 years. If financed through Pag-IBIG, SSS, GSIS, or a commercial bank, compare the monthly savings with the monthly loan payment. If your solar savings are ₱4,000 a month and your loan payment is ₱3,500, you are ahead by ₱500 monthly. If the loan payment is higher than the savings, solar may still be a good long-term investment, but it will not immediately improve cash flow.

Before asking for a quote, prepare your last 12 months of electric bills, average monthly kWh use, and clear photos of your roof and electrical panel.

Solar is not about free electricity. It is about buying part of your electricity in advance and reducing exposure to future rate increases.

The best solar system is not the biggest one. It is the one that fits your actual use, roof, budget, and ability to pay.