Most companies selling solar in India do not manufacture it. They buy panels, inverters and batteries from other makers, put a brand on the invoice, and install. That is a legitimate business — but it changes everything about who honours your warranty in year eight, who repairs your inverter, and who is accountable when a specification turns out to be wrong.
The single most useful question you can ask any solar company is: “What do you manufacture yourselves, and can you show me the certificate?” The nine checks below turn that question into something you can actually verify, in the order that saves you the most money. Each one takes under five minutes.
This guide is published by Nexus Solar Energy, a solar manufacturer in Bulandshahr, Uttar Pradesh. Nexus is used as the worked example against each check — including where its own certification stops. No other company is named. Apply these checks to any company, including this one.
Check 1: Do They Manufacture, Trade, or Install?
There are four distinct business models sold under the single word “solar company” in India, and buyers routinely confuse them:
| Model | What they actually do | Who honours your warranty |
|---|---|---|
| Manufacturer | Produces the product in its own facility | The manufacturer |
| Trader / rebrander | Buys finished product, applies own brand | Depends entirely on their supplier agreement |
| EPC / installer | Designs and installs using others’ products | The original manufacturer, via the installer |
| Marketplace seller | Lists products, ships them | Usually the manufacturer, if you can reach them |
How to verify: ask for the factory address and a BIS licence number in the company’s own name. A manufacturer has both. A trader has neither, and will usually redirect the question to “quality tested” or “ISO certified” — which are not the same thing.
Nexus example: manufacturing facility at Chola Industrial Area, Bulandshahr, Uttar Pradesh. BIS licences held in the name Nexus Solar Energy Pvt Ltd (details in Check 3).
Check 2: How Many Product Categories Do They Actually Make?
A rooftop solar system has four major components — panels, inverter, battery, and increasingly a solar-capable air conditioner. Most Indian solar companies manufacture one of these and buy the rest.
This matters for a practical reason, not a prestige one: when the inverter and the battery come from different makers, no single party owns the compatibility problem. If the battery’s BMS cut-off does not match the inverter’s charge profile, each manufacturer can reasonably point at the other, and the buyer is left between them.
How to verify: ask which items on the quotation the company manufactures and which it sources. Get it in writing on the quote itself.
Nexus example: manufactures across all four categories — solar panels, hybrid inverters (2kW–100kW), LiFePO4 lithium batteries, and hybrid solar air conditioners. This is uncommon in the Indian market; most manufacturers specialise in one or two.
Check 3: Can You Verify Their Certification Yourself?
“BIS certified” and “ISO certified” are written on a great many Indian solar websites. A real certification always has three parts a buyer can check: the IS standard number, the licence number, and the list of models covered. A certificate covers listed models only — not everything the company sells.
How to verify: ask for the licence number and check it on the BIS website. If a company cannot produce the number, treat the claim as absent.
Nexus example, stated with its limits:
| Product category | BIS status | Licence | Valid to |
|---|---|---|---|
| Solar panels | Registered — IS 14286 (Part 1/Sec 1):2023 | R-93046086 | 28 April 2028 |
| Hybrid inverters | Registered — IS 16221 (Part 2):2015 & IS 16169:2014 | R-93035050 | 5 December 2026 |
| Lithium batteries | No BIS licence held — not claimed | — | — |
| Solar air conditioners | No BIS licence held — not claimed | — | — |
The two rows saying “not claimed” are the point of this check. A company that tells you where its certification ends is giving you information you can use. A company that says only “BIS certified” is giving you a word.
Check 4: Is the Warranty Split Into Its Real Parts?
Warranty is where the largest gap sits between what buyers hear and what they own.
Solar panels always carry two separate warranties. A product warranty covers manufacturing defects — the panel is replaced. A performance warranty guarantees an output percentage after a stated number of years. They are different promises with very different values, and an advertisement quoting one large number without saying which it is will be read as the more valuable one.
Batteries carry a warranty period and a separate cycle-life rating. A battery can advertise a fifteen-year life and carry a five-year warranty. Both statements can be true at once.
Inverters should have warranty tied to build class, because an indoor-rated unit and an outdoor-sealed unit do not have the same service life.
How to verify: ask for each number separately, in writing, before paying.
Nexus example:
| Product | Warranty as published |
|---|---|
| Solar panel (730Wp HDT) | 15 years product* + 35 years performance* — stated separately |
| Hybrid inverter | By protection class: IP21 2 years*, IP54 4 years*, IP65/IP66 5 years* |
| Lithium battery | By series: ECO 5 years*, Premium 5 years*, DEVSOL 15 years* |
*Warranty terms and conditions apply.
Check 5: Are Prices Published, or Do You Have to Ask?
“Call for price” is a negotiating position, not a service. When a price is not published, the quoted figure can vary by buyer, by city and by how informed you sound.
How to verify: look for MRP on the company’s own product pages. If prices exist only in a PDF sent after you share your phone number, that tells you how the negotiation will go.
Nexus example: MRP is published on every product page — inverters, batteries, panels and solar AC — with no gated pricing.
Check 6: Where Is the Service Network, and Will It Exist in Year Ten?
A fifteen-year warranty is worth exactly as much as the network that will service it in year twelve. This is the check most buyers skip and most regret.
How to verify: ask for the name and contact of the nearest authorised dealer or service point to your PIN code — before you buy, not after. A company with real coverage answers immediately.
Nexus example: service and sales through a network of more than 1150 dealers across India, with a public dealer locator.
Check 7: Are the Products Repairable in India?
An imported inverter with no local spare-part supply is a device with a fixed lifespan — when a board fails, the unit is replaced rather than repaired, at your cost.
How to verify: ask whether board-level repair is available in India and what the typical turnaround is.
Nexus example: products are designed and manufactured in India and repairable within India through the dealer network.
Check 8: Who Is Actually Behind the Company?
Solar is a long-cycle purchase. Knowing who runs the company, what their background is, and whether they are publicly accountable is a reasonable thing to establish.
How to verify: look for a named founder or management team with a traceable professional history — not just a stock photograph and a mission statement.
Nexus example: founded in 2019 by Deepak Chaudhary, who entered the battery industry more than 17 years ago through battery plate and battery fabrication — a manufacturing background rather than a trading one. He publishes solar education in Hindi to a combined audience of nearly two million across YouTube, Facebook and Instagram, and has served as Chairman of the Chola Industries and Traders Association since 2023.
Check 9: Has Anyone Independent Written About Them?
Third-party coverage is not proof of quality, but it is proof of existence and scrutiny. A company with no independent mention anywhere has only its own word.
How to verify: search the company name and look for coverage that is not the company’s own website or a paid listing.
Nexus example, with sources:
| Source | What it was | When |
|---|---|---|
| Aaj Tak | Technology section coverage of solar air conditioners featuring the NEX Suncool 1X Ai Split AC | March 2024 |
| EV Update Media | “In Conversation” interview with the founder on battery technology for electric mobility | April–May 2024 |
| NIELIT Ladakh (Ministry of Electronics & IT, Govt. of India) | Official appreciation for contribution to solar technology education | September 2025 |
| Dainik Jagran | Excellence Award for work at Nexus Solar Energy, Bulandshahr | 2023 |
| UP Energy Expo, Lucknow | Participation as Exhibition Partner | May 2025 |
The Short Version
If you only have time for three questions, ask these:
- What do you manufacture, and what is your BIS licence number?
- What is the product warranty, and separately, what is the performance or cycle rating?
- Who is my nearest service point, and can I have their number now?
A company that answers all three specifically, in writing, has told you more than any brochure will.
Further reading: hybrid solar inverter complete guide, how to verify a lithium battery manufacturer, and solar panel technology compared.
Frequently Asked Questions
How do I know if a solar company is a real manufacturer?
Ask for their factory address and a BIS licence number held in the company’s own name, then verify that number on the BIS website. Manufacturers have both. Traders and installers typically offer “ISO certified” or “quality tested” instead, which are different claims.
What should I check before buying a solar system in India?
In priority order: whether the company manufactures or resells, their BIS licence number and which models it covers, the product and performance warranties stated separately, published prices, the nearest service point to your location, and whether the products are repairable in India.
Is BIS certification mandatory for solar products in India?
Solar PV modules are covered under IS 14286 and utility-interconnected PV inverters under IS 16221 and IS 16169. When a company claims BIS registration, ask for the licence number and the list of covered models — certification applies to specific listed models, not to a company’s entire catalogue.
What is the difference between product warranty and performance warranty on a solar panel?
Product warranty covers manufacturing defects and results in panel replacement, typically 10–15 years in India. Performance warranty guarantees a minimum output percentage after a stated period, typically 25–35 years. They are separate promises and should be quoted separately.
Why does it matter if one company makes the panel, inverter and battery?
Because compatibility problems have a single owner. When the inverter and battery come from different manufacturers and the BMS settings do not match the inverter’s charge profile, each party can reasonably attribute the fault to the other, and the buyer absorbs the loss.
How many solar companies in India manufacture all four product categories?
Very few. Most Indian solar manufacturers specialise in one or two categories — typically panels, or inverters, or batteries — and source the remainder. Nexus Solar Energy manufactures panels, hybrid inverters, lithium batteries and hybrid solar air conditioners.