How to Verify a Rooftop Solar Vendor's Claims Before You Invest in Your Business

Before signing a rooftop solar contract, verify three things independently of the vendor's pitch: confirm the proposed modules appear on the Ministry of New and Renewable Energy's Approved List of Models and Manufacturers, ask…

India's Rooftop Solar Boom Has a Trust Problem Underneath It

Rooftop solar in India is growing faster than at almost any point in the last decade. The country added 7.1 GW of new rooftop capacity in calendar year 2025, a jump of over 123% year on year from just 3.2 GW in 2024, according to Mercom India's Q4 and Annual 2025 Rooftop Solar Market Report. By the end of FY2026 (March 31, 2026), India's total installed solar power capacity crossed 150 GW, with rooftop additions alone up 69% year on year, as reported by pv magazine.

That pace of growth is good news for anyone who wants cheaper power. It is also exactly the environment in which weak vendors thrive: more buyers entering the market for the first time, more installers competing on price, and less time for any single buyer to check who they are actually signing with. A July 2026 report from SaurEnergy documented recurring patterns, from installers who collect a 30 to 50 percent advance and disappear, to counterfeit domestic-content certification stickers applied to non-compliant modules, including one verified case where a dealer lost roughly ₹1 lakh to a fraudulent supplier during a stock shortage. These are not edge cases confined to small residential jobs. They are symptoms of an industry scaling faster than its verification systems.

Why Business Owners Struggle to Separate a Credible Quote From an Inflated One

For a factory, warehouse, or commercial property owner, the stakes are higher than for a home. A rooftop system sized for a facility involves a larger roof structure, a more complex load profile, and a contract that can run into years of financed payments. Yet the commercial and industrial (C&I) segment is still the smaller half of the rooftop story: residential installations made up roughly 76% of 2025's rooftop additions, with C&I accounting for the remaining share, per Mercom India's data cited above. Fewer C&I deals also mean fewer public reference points for a business owner trying to judge whether a quoted payback period, generation estimate, or degradation figure is realistic.

The financing side compounds the problem. Research from IEEFA and JMK Research on India's C&I rooftop market found that lenders often treat rooftop projects as higher risk than utility-scale solar, which pushes up interest costs and slows approvals, even though rooftop C&I systems frequently offer stronger returns. The same research estimated that micro, small and medium enterprises alone sit on roughly 15 GW of unused rooftop potential, held back largely by limited access to financing and by uncertainty over which vendors and numbers to trust. When the underlying data is hard to verify, business owners understandably default to caution, and legitimate projects get delayed alongside the ones that deserved delay.

What Is Actually Driving the Confusion

Three technical gaps explain most of the exaggerated claims a business owner is likely to encounter.

Module sourcing and certification. Not every panel sold in India is manufactured by the company whose brand is on the box. The Ministry of New and Renewable Energy created the Approved List of Models and Manufacturers specifically because, in its own words, "the reliability of producer is essential to protect the consumer interests," after finding that some manufacturers were sourcing equipment elsewhere and rebranding it. Modules used in net-metered or open-access photovoltaic installations are required to come from ALMM-listed manufacturers, and checking that list takes a buyer about five minutes.

Degradation and generation projections. Every solar module loses a small amount of output every year. Industry data compiled by Solarsquare puts typical first-year degradation at 0.7 to 0.8%, settling to roughly 0.5 to 0.8% per year after that, meaning a well-specified system should still be producing a large majority of its original output after 25 years. A quote that promises flat, undiminished output for decades, or that shows no degradation curve at all, is describing a system that does not exist in physics.

Regulatory and metering complexity. Net metering rules, DISCOM approval timelines, and open-access eligibility vary by state and change periodically, which is precisely why India's broader renewable energy push depends on installers who track policy at the state level rather than quoting national averages. A vendor who cannot explain your specific state's net-metering process in plain language is unlikely to manage the approval on your behalf as smoothly as promised.

The New Buying Criteria: What a Smart Industrial Buyer Checks Before Signing

Given all of the above, the question worth asking is not "who has the lowest quote" but "who can prove their numbers." That shifts the buying criteria toward verification rather than persuasion:

• Documented ALMM listing for the exact module model proposed, not a generic manufacturer name.
• A written, degradation-linked performance guarantee rather than a single headline efficiency number.
• Remote, buyer-accessible generation monitoring so output can be checked independently of the installer's own reporting.
• A named track record on DISCOM and net-metering approvals in your specific state, not just "pan-India experience."
• Transparent, GST-clear quotations that separate equipment, installation, and any financing costs so there is nothing folded into a vague lump sum.
• Financial and safety credentials for the EPC firm itself, since a 25-year asset is only as reliable as the company that will still be answering the phone in year ten.

What to Look for in a Rooftop Solar EPC Partner

• Willingness to share ALMM documentation and past DISCOM approval paperwork before you sign, not after.
• A generation estimate that comes with the assumptions behind it (irradiance data, shading losses, degradation rate) rather than a single number.
• A maintenance and monitoring plan that continues after commissioning, not just an installation timeline.
• Clear answers, in writing, to what happens if actual generation falls meaningfully short of the estimate.

Where This Leaves a Business Owner Evaluating Quotes Today

None of this means every vendor quote is inflated, and it does not mean the fastest-growing market in Indian solar is unsafe to enter. It means the burden of verification has shifted, sensibly, onto the buyer, and that a few pointed questions can separate a dependable 25-year partner from a company that will not answer the phone in year three. This is the same discipline SKP Solar World applies to its own rooftop EPC proposals for homes, businesses, and industrial facilities: every module we specify is checked against the current ALMM listing, every generation estimate ships with its assumptions and a degradation curve, and every commissioned system is handed over with monitoring access the client controls, not just the installer.

If you want to see what that discipline looks like against your own numbers, you can compare your current electricity bill with a projected solar savings estimate from SKP Solar World, request the same ALMM documentation and degradation curve described above from SKP Solar World's engineering team, or ask for a written performance guarantee the way SKP Solar World structures its rooftop EPC contracts before you compare it against any other quote you are holding.

The most useful next step is usually the smallest one: take your last two or three months of electricity bills and get a no-obligation site and savings assessment from SKP Solar World. There is no pressure to commit, and the numbers you get back will make every other quote in your inbox easier to judge on its merits.

Frequently Asked Questions

How do I check if a solar module is ALMM listed?

The Ministry of New and Renewable Energy publishes and regularly updates the Approved List of Models and Manufacturers on its official website, covering both finished modules (List-I) and solar cells (List-II). Ask your vendor for the exact model number and manufacturer name they intend to install, then check that combination against the current published list before signing, not after the modules arrive on site.

What performance guarantee should a rooftop solar EPC provide for a business?

Look for a guarantee tied to a year-by-year degradation curve, typically reflecting roughly 0.7 to 0.8% loss in the first year and 0.5 to 0.8% per year afterward, rather than a single flat efficiency claim. The guarantee should specify what happens, in writing, if measured generation falls short of the projected curve.

How can I verify a vendor's net metering and DISCOM approval track record?

Ask for references from businesses in your own state who went through net metering approval with that vendor in the last 12 to 18 months, since rules and DISCOM practices vary by state and change over time. A vendor active in your state should be able to name the typical approval timeline and the documents it requires without hesitation.

What red flags suggest a solar vendor is exaggerating its claims?

Common warning signs include generation estimates with no stated assumptions, a "25 year warranty" with no degradation schedule behind it, reluctance to share ALMM documentation, unusually large upfront advances relative to project size, and pricing far below other quotes during a period of supply shortage, which industry reporting has linked to fraud rather than genuine savings.

Does a lower quote always mean a worse system?

Not necessarily, but a lower quote should still be able to answer every verification question above. The goal is not to assume the cheapest or most expensive quote is correct, but to require every vendor, regardless of price, to document its module sourcing, degradation assumptions, and approval track record before you decide.

Sources

• Mercom India: Rooftop Solar Growth Accelerates in India with 7.1 GW Added in 2025, a 123% YoY Jump
• pv magazine: India Hits 150 GW Solar Milestone
• IEEFA: The Rooftop Solar Commercial and Industrial Market in India
• Ministry of New and Renewable Energy: Approved List of Models and Manufacturers (ALMM)
• Solarsquare: Solar Panel Degradation in India
• SaurEnergy: The Solar Rush Has a Dark Side, Three Common Frauds Plaguing Solar Buyers