3 kW or 5 kW when you sit near Punjab’s free-units line

If your billed use swings around 300 units a month, we usually size for 3 kW first, then move to 5 kW only if your daytime use and sanctioned load justify it. This avoids paying for extra export that has no value in our calculations under PSPCL net metering.

What 3 kW and 5 kW actually produce here

We plan on about 135 units a month from each kW of panels in Punjab, averaged over the year. With TOPCon panels, output can reach up to about 180 units per kW in the sunniest months. These are estimates: real output depends on the roof’s direction and shade, dust, the weather and the panels and inverter used.

• 3 kW: about 306 units a month across the year
• 5 kW: about 510 units a month across the year

In December and January fog, plan on about 75% of that. Heat, dust and shade also cut output. The units you use as they are made are worth most. Whatever goes out to the grid is settled under PSPCL’s rules, and we give export no value in our saving math.

When 3 kW is the right call

If you are near the free-units line, 3 kW on-grid often fits better because:

• Its planned output is close to 300 units a month, which is around the free-units threshold.
• It reduces daytime draw without pushing too much into export in low-use homes.
• It fits more roofs. Allow about 100 sq ft per kW, so about 300 sq ft shade free for 3 kW.

Price matters too. Our installed on-grid estimates:

• 3 kW: ₹1,78,000 to ₹1,95,800 before subsidy
• 5 kW: ₹2,50,000 to ₹2,75,000 before subsidy

Every price on our site is a range and an estimate. On-grid costs less than hybrid at the same size. If backup is not a must, on-grid near the free line keeps the spend in check. You can see more detail on sizes and current estimates at our 3 kW and 5 kW pages: 3 kW in Punjab and 5 kW in Punjab.

When 5 kW makes sense

Choose 5 kW if at least one of these is true:

• Your sanctioned load allows 5 kW. A rooftop system can be at most 100% of sanctioned load.
• Your daytime use is high for most of the year. For example, multiple fans, a 1.5 ton AC in the day, or work-from-home loads that align with sun hours.
• Your two-month billed units are often well over 600, not just by a little.

With 5 kW you add about 510 planned units a month across the year. In homes near 300 units a month, much of that can spill to export in mild seasons. Our math does not book value for exported units, so we try to match size to self-use first.

If you plan to add an EV or another AC soon, size for that only if you will use it in the day. If the new load is mainly at night, a bigger on-grid array still exports in the day. For night use with backup, see our hybrid systems and run the hybrid calculator to see how a battery shifts some solar to evening. Hybrid always costs more at the same size because of the inverter and battery.

What the subsidy changes, and what it does not

PM Surya Ghar pays ₹30,000 per kW for the first 2 kW and ₹18,000 for the third, capped at ₹78,000. Both 3 kW and 5 kW reach the same ₹78,000 cap on eligible on-grid or hybrid systems with DCR ALMM panels. The subsidy is paid into your bank account 30 to 45 days after the DISCOM inspection. It never comes off the invoice, and it never goes to a lender or an installer. For steps and documents, read our Punjab subsidy guide.

Subsidy does not change net metering math. We still size to maximise self-use.

How we decide on a roof

On a site visit we measure:

• Shade-free area. Plan on about 100 sq ft per kW.
• Main daytime loads and when they run.
• Sanctioned load and meter position for net metering.

Bring a recent bill and a list of appliances. If you are still building, try our new-house calculator. If you are in an existing home, use the quick solar calculator with your monthly units. Both use the same planning figure of about 135 units per kW a month. For panel and inverter options, see UTL solar panels and inverters. We supply as a UTL Solar distributor in Phase 8B, Mohali, and install with our own team across Mohali, Kharar, Zirakpur, Derabassi, Chandigarh, Panchkula, New Chandigarh, Landran, Banur, Lalru, Naya Gaon, Kurali, Morinda, Ropar, Fatehgarh Sahib, Chamkaur Sahib and Khamanon. Product warranties are the manufacturer’s.

A simple path if you hover around 300 units

• Start with 3 kW on-grid if your two-month bill usually comes in at or under 600 units. It matches the free-units line across the year better.
• Move to 5 kW only if your sanctioned load allows it and you can use a larger share of the output in the day for most months.
• Keep winter fog in mind. Plan on about 75% of the usual output in December and January.

If you want us to mark exact panel positions and check sanctioned load, send a bill photo and a roof photo from the street using the contact on our company page. We can also walk you through on-grid vs hybrid if backup is part of the brief.