How to Audit a Solar Quote: Seven Things to Check Before You Sign

More than 4 million Indian households have gone solar under PM Surya Ghar Muft Bijli Yojana, according to CEEW's June 2026 tracking data. That number is a real achievement, but it obscures a quieter problem. Nearly 18% of DISCOM net-metering inspections result in system rejection, per MNRE Standard Operating Procedure data, meaning an estimated 720,000 households may be sitting on disqualified systems and roughly ₹5,616 crore in Central Financial Assistance that may never arrive.

The common thread in most of those cases: the problem was visible in the quote, weeks before installation began.

A solar installation quote is not a product brochure. It is a financial instrument that either protects or exposes the buyer over a 25-year horizon. The seven checks below are the minimum standard for reading one intelligently.

Check 1: What does a real solar generation estimate look like, design-basis or realistic output?

Every solar quote includes an annual generation estimate. The number that matters is not the headline figure, it is the methodology behind it.

A design-basis estimate assumes ideal panel orientation, no shading, zero soiling losses, and nameplate inverter efficiency. A realistic output estimate layers in your roof's actual azimuth, local irradiance data (ideally from MNRE's solar radiation atlas), site-specific shading analysis, and inverter efficiency under real operating temperatures. See Zenergize's real 25-year generation model for how these factors compound.

Ask your installer to show the generation calculation, the inputs and the irradiance dataset used. If they cannot, the estimate is aspirational.

One indicator of a credible quote: an explicit performance ratio (PR) figure alongside the kilowatt-hour projection. PR is the ratio of actual system output to the theoretical maximum given available irradiance, and a quoted PR within the expected range for your climate zone signals that the estimate has been designed, not guessed.

If your system includes a monitoring platform that tracks real-time generation curves and PR, such as ZenSense, confirm that monitoring access is included in the contract, not sold separately. Ongoing monitoring is the only way to independently verify that the system is delivering its promised generation after commissioning.

Check 2: Do the panel specifications match the ALMM list?

Under PM Surya Ghar, Central Financial Assistance is conditional on the panels being sourced from manufacturers on the MNRE Approved List of Models and Manufacturers (ALMM). The maximum CFA, ₹78,000 for a 3 kW system, is available only for ALMM-compliant components.

Check the brand and model number listed in your quote against the live ALMM panel list at mnre.gov.in. Two things to verify: the manufacturer is listed, and the specific model number in the quote appears on the portal. ALMM listings are updated periodically; a model listed six months ago may have been removed.

Any installer providing a PM Surya Ghar quote should be able to share the ALMM listing for the exact panels being proposed. Resistance to that request is a flag.

Check 3: Does the inverter carry a valid BIS IS 16221 certificate?

India's Bureau of Indian Standards mandates IS 16221 certification for all grid-tied solar inverters sold in the country. This standard covers electrical safety, electromagnetic compatibility, and grid-connection behaviour. A grid-tied inverter without a valid BIS IS 16221 certificate is not legally compliant, and will fail DISCOM inspection.

Your quote should name the specific inverter model. Before signing, ask the installer for the BIS certificate number for that exact model. You can verify it on the BIS product registration portal at bis.gov.in, or the CRS dashboard at crsbis.in. See Zenergize's full explainer on verifying BIS IS 16221 for the step-by-step process.

Also check the inverter's rated capacity against your sanctioned load and proposed system size. An undersized inverter is one of the most common causes of generation shortfall in year one.

Check 4: What exactly does the warranty cover, and for how long?

Warranty clauses are where solar quotes diverge most sharply, and where most buyers stop reading too soon.

A credible residential solar quote should specify:

• Panel performance warranty: typically 25 years for ≥80% output retention
• Panel product warranty: typically 10–12 years covering manufacturing defects
• Inverter warranty: duration, covered failure modes, and service response commitment
• Workmanship warranty: covering installation quality, roof penetrations, and water ingress

The inverter warranty deserves the closest scrutiny. Read which failure modes are excluded. An inverter rated to operate at full power across an ambient temperature range of 40–55°C offers meaningfully different protection in Indian conditions than one rated only to 40°C. Heat-related stress is the primary failure mode for residential inverters in the subcontinent; a warranty that excludes it is worth substantially less than its stated term.

The 87% of solar buyers who recommend their installer to others do so primarily because of post-installation support, not installation quality, per CEEW's June 2026 survey. The warranty is the contractual expression of that support. Compare it across quotes before you decide.

Check 5: Does the subsidy structure in this quote actually protect your CFA?

PM Surya Ghar's Central Financial Assistance is credited after successful DISCOM net-metering inspection and system commissioning, not at installation. The sequence is: installation → DISCOM inspection → commissioning certificate → CFA credit.

Several quote structures inadvertently shift the inspection risk entirely onto the buyer:

• Full payment before inspection: Once the installer has been paid in full, their incentive to resolve inspection snags is limited. Structure at least one tranche, 20–30% is typical, to be held until the commissioning certificate is issued.
• No DISCOM filing commitment: Your quote should specify who files the net-metering application, what timeline they commit to, and who bears the cost of any re-inspection if the first fails.
• No performance commitment: If the system underperforms its stated generation estimate in year one, what recourse do you have? Some contracts include a make-good clause. Most do not.

With roughly one in five new installations encountering a DISCOM inspection hurdle, the allocation of that risk is not hypothetical, it belongs in the contract.

Check 6: Are the payment milestones structured to keep leverage in your hands?

Milestone-based payment is the standard financial protection tool for residential solar buyers. A defensible structure looks like this:

• 30–40% on contract signing (mobilisation and material procurement)
• 30–40% on delivery and structural mounting (racking installed, panels racked)
• 20–30% on electrical commissioning and DISCOM inspection clearance

If a quote asks for more than 50% upfront, ask for a written explanation. That is not market-standard, and in a competitive installation market, it rarely has a legitimate justification.

Also check whether the contract specifies a commissioning date distinct from an installation date. Commissioning, defined as the date the system is energised and generating, starts both the warranty clock and the DISCOM application timeline. Vague language about "completion" that conflates the two can delay both.

Finally, check for penalty clauses tied to DISCOM filing delays. Every week your net-metering application sits unfiled is a week your generation goes uncompensated under the net-metering framework.

Check 7: How do I check if my solar installer is empanelled with my DISCOM before I sign?

An installer who is not empanelled with your state DISCOM cannot file the net-metering application on your behalf. Without that filing, your system cannot be commissioned under PM Surya Ghar, and your CFA cannot be processed regardless of how compliant the hardware is.

Every DISCOM publishes its empanelled installer list, typically on the state electricity regulatory commission portal or the DISCOM's own website. Search for your installer's company name or GST number. Confirm the listing is active and not suspended.

If your installer is not empanelled, ask how they intend to handle the DISCOM filing. Some non-empanelled vendors work through an empanelled EPC partner, an arrangement that may be legitimate but should be disclosed in your contract, with the empanelled entity named explicitly and their responsibilities defined. See Zenergize's EPC offering for what an empanelled partnership should look like.

The Standard Your Quote Should Meet

A solar installation is a 25-year financial commitment. The seven checks above represent the minimum standard for evaluating whether a quote protects that commitment, not all of them, just the ones most likely to determine whether your system clears DISCOM inspection, whether your CFA arrives, and whether your installer is still reachable if something fails in year three.

Roughly 720,000 Indian households may currently hold at-risk PM Surya Ghar claims, a collective exposure of approximately ₹5,616 crore, because one or more of these criteria were not met before installation. Most of that risk was present in the quote, before anything was installed.

If you want to verify your current quote against these criteria, view Zenergize's product specifications and certifications or contact the team directly.