How to read a solar quote: the 7 numbers that actually matter

You asked three installers for quotes. You got back three PDFs. Each one quotes a different kW, a different price, a different brand of panel, a different warranty period. The totals don't even line up.

Welcome to the most confusing 20 minutes of a solar buyer's life. Here's how to read a quote like an advisor, not a homeowner.

1. System size in kW — but only if everyone's solving the same problem

Every quote starts with a kW number. That's the total peak power the panels can produce in ideal sun. But the kW is only meaningful in context: sized for what?

If installer A quotes 3 kW and installer B quotes 5 kW for the same home, one of them is wrong — or they're solving for different goals. Maybe A is sizing for current bill, B is sizing for future EV. Ask each installer what they sized for. If they don't have a crisp answer, that's a flag.

2. Cost per watt — the only honest unit comparison

Take the gross price (before subsidy) and divide by the system wattage. That's your cost-per-watt, the cleanest apples-to-apples number across quotes of different sizes.

2026 India ranges:

• ₹55–65/W — budget Tier-2/3 city, basic Tier-1 panels, single-phase inverter
• ₹65–85/W — mainstream metros, Tier-1 panels, decent inverter brand, 5-year install warranty
• ₹85–110/W — premium metros, hybrid system with battery, top-tier panels (LG, Tata, Vikram), 10-year install warranty
• ₹110+/W — either a premium hybrid with high-quality battery, or you're being overcharged

If two quotes are wildly apart on ₹/W, the difference is either in the components or in the margin. Make the installer tell you which.

3. Subsidy — the exact ₹, not the "eligible up to"

Every quote will mention PM Surya Ghar subsidy. Most will quote "up to ₹78,000." That's the maximum — not what you'll get.

The actual amount depends on your system size:

• 1 kW: ₹30,000 central
• 2 kW: ₹60,000 central
• 3 kW or more: ₹78,000 central (capped here)

Some states add a top-up. Delhi and UP add ₹30K (total ₹1.08L for 3 kW+). Haryana adds nothing. The state component depends on your DISCOM — not just your geography.

Demand the exact ₹ figure for your specific kW and state in the quote. Any installer hedging on this is either lazy or hoping you won't check.

4. Net price to you

Gross price − subsidy = net price. Sounds obvious. But how the subsidy flows matters:

• Subsidy advance: some installers front the subsidy and you pay net. Cleaner cash flow for you, but the installer is bearing the float — expect a slightly higher gross price.
• Subsidy reimbursement: you pay gross upfront and DBT credits the subsidy to your bank account 30–90 days post-install. Lower gross price but you bear the float.

Neither is better in absolute terms — just make sure you know which model the quote assumes, and that the net-to-you number reflects it.

5. Inverter brand and capacity

The inverter is the single most failure-prone component in a solar system. Panels last 25 years; inverters typically need replacement at year 10–12. The brand and warranty matter more than installers tend to highlight.

• Tier-1 inverter brands (Tata Power Solar, Luminous, Microtek, Sungrow, Growatt): 5–10 year warranty, parts available everywhere
• Mid-tier (UTL, Su-Kam, generic Chinese OEM): 2–5 year warranty, parts harder to source post-warranty

If a quote saves you ₹15K by switching from Tier-1 to mid-tier inverter, that's ₹15K you'll likely spend again at year 8 when it fails. The lifetime cost is higher.

6. Battery — if quoted, check kWh and chemistry

If your quote includes a battery (hybrid system), pay close attention. Battery is where the most variation hides:

• Lead-acid: cheap (₹50–80K for 5 kWh), 3–5 year life, low depth-of-discharge. Almost never the right call for new installs in 2026.
• Lithium (LFP): ₹1.2–1.8L for 5 kWh, 10–15 year life, 80–90% DoD. The standard for residential hybrid installs.
• Lithium (NMC): higher energy density but lower cycle life. Less common in residential.

Battery quoted in "Ah"? That's a flag — ask for kWh, which is the unit that actually matches your home's consumption.

7. What's NOT in the quote

Maybe the most important number is the one missing. Walk through the quote and check for:

• Net-metering paperwork — is the installer doing the DISCOM filing? At what fee?
• Civil work — mounting structure, cable trays, weatherproofing. Often quoted separately or as "extra at actuals."
• Earthing / lightning protection — required by code, sometimes omitted to lowball the headline.
• Performance warranty — panel manufacturer warranty (25 years, linear degradation) is separate from installer warranty (1–5 years on workmanship). Both matter.
• AMC / maintenance — first-year AMC free? Subsequent years at what rate?

The biggest gap between installers usually isn't the ₹ number on the front page. It's the line items missing from the back.

How Watt Matters changes this

Reading three quotes side-by-side is an analyst's job — not a homeowner's evening hobby. When you book an independent assessment with us, all installers quote against the same baseline: our standardised report. Same kW assumption. Same BOM template. Same warranty structure. Same line items in every quote.

Then comparing quotes becomes what it should be: a 5-minute review of price + warranty + installer reputation, not a 3-hour exercise in deciphering whose sizing assumption is more credible.

Try the calculator first to see if solar makes sense for your home. The assessment kicks in only when you're ready to commit.