Before you buy · for anyone, anywhere
Study solar before you buy it. Even if not from us.
We may not work in your area. Read this anyway — it's written so anyone can check a solar quote properly, whoever is quoting.
A phone is old at five. Solar is only getting started.
Most things you buy are finished by year five. A solar roof has only just paid for itself by then — the return is everything after. So it has to be built for twenty years, not seven or eight.
A phoneReplaced at five
A solar roofBuilt for twenty
A roof built down to a priceIllustrative
The third bar is the pattern we see across the district. A cheaper roof wins the first few years. Then a thin frame, shallow earthing or a rusted fastener makes itself known around year seven — and the repair eats the return. Building it properly may cost a few months of power bills more, and last twice as long.
Almost nobody checks this deeply.
The installer is trying to fit as many roofs as he can. The customer believes the whole system lasts 30 years, because the dealer said "30-year warranty".
It doesn't. Thirty years is the panel's output warranty — a promise about how much electricity the panel still makes. The frame it sits on, the wiring, the earthing and the footings carry no such promise. They are exactly as good as what went into them, and nobody is coming back in year nine to replace a rusted bolt for free.
Very few people study any of this. Those who try find a market where it is hard to tell what is right — so they trust the brand they have heard of from other products, and the rest of the roof goes unexamined.
- Panel · output
- 30 yrs · 87.4% at 30
- Panel · product
- 12 years
- Inverter
- usually 5–10 years
- Frame, footings, earthing
- As good as the materials
- Cables, connectors, fasteners
- As good as the materials
- Any of the above
- Void if badly installed
Warranties hold only when the maker's guidelines are followed. A frame that flexes in wind micro-cracks the glass — and that is physical damage, which no panel warranty covers.
How deep people check — and what actually decides year twenty.
Every level below the first is where a cheap roof hides. Tap each one for what to ask, what a good answer looks like, and what a cheap one looks like.
How far most buyers get
Bar = roughly how many people check this before signing.
Panel and inverter brandOften a name known from fans and TVs, not the best in solar
Structure materialGP or GI
Structure size, thickness, weightKilos per kW; whether welds are ground and primed
Cables, connectors, distribution boxBrand and size, surge protection, breakers
Earthing, footings, fastenersPits and depth, concrete, stainless steel
Check all five. Then compare quotes.
01 · Panel and inverter
Ask: which panel brand and cell type; the product warranty and the output warranty as two separate numbers; the inverter brand and its own warranty in years.
Good looks like: a maker that produces the cell as well as the panel, TOPCon rather than older PERC, 12 years product and 30 years output in writing. Inverters from the brands engineers specify worldwide — GoodWe, SolarEdge, SMA, Sungrow, Enphase, Hoymiles — not a name you know from fans.
Cheap looks like: "30-year warranty" with no split, a brand chosen because the dealer stocks it, an inverter nobody can name the service centre for.
02 · Structure material
Ask: GP or GI? Hot-dip galvanised or just painted? Is the maker's stamp on the pipe?
Good looks like: GI structural tube with the mark rolled into the steel — on ours it reads TATA Structura — so you can check it on delivery day.
Cheap looks like: thin GP tube or mild steel, painted silver so it looks the same on day one. It isn't the same in monsoon seven.
03 · Size, thickness and weight
Ask: the pipe section and wall thickness in millimetres; roughly how many kilos of steel per kW; whether welds are ground and primed; whether legs sit on concrete or are drilled into the waterproofing.
Good looks like: a heavy section — we use about fifteen kilos of GI per kW where the market uses about ten — every weld ground and primed, and a concrete footing under every leg so nothing is drilled into the slab.
Cheap looks like: a frame you can flex by hand. In wind it moves, the glass micro-cracks, output falls a little every year, and the panel warranty calls it physical damage.
04 · Cables, connectors and the distribution box
Ask: DC cable brand and size; conduit type; connector brand; surge-protection and breaker brands; whether there is a lightning arrester.
Good looks like: named cable (ours is Polycab), rigid conduit outside and weather-grade flex where it must bend, original Stäubli connectors, a surge protector from Mersen or Citel, breakers from ABB, Mersen or Schneider.
Cheap looks like: unbranded cable, connectors that look like the original and account for most connector failures, and no surge protection at all — one strike away from a dead inverter.
05 · Earthing, footings and fasteners
Ask: how many earthing pits, how deep, what electrode and what compound; what the panels are held with; what the bolts are made of.
Good looks like: three pits at 2.5 metres with full-length GI electrodes and conductive compound — the depth is what keeps earthing working through a dry March. Stainless steel on every nut, bolt and washer. Panels held with J-bolts through the frame and clamps.
Cheap looks like: one shallow pit you will never be able to inspect, mild-steel bolts that rust in two monsoons, panels clamped only — the slowest, costliest parts of the job are the ones nobody can see, which is exactly why they get skipped.
Sometimes the right answer is: don't.
We see homes with a ₹300 bill putting solar on the roof. Solar cannot fix a ₹300 bill.
KSEB's fixed charge and meter rent stay whether you generate or not. On a bill that small, those are most of the bill. What solar can actually remove is about ₹1,100 a year — against a system that costs lakhs. It will not pay for itself in its lifetime, and if it was built cheaply it won't live long enough to try.
Solar starts to make sense when the energy charge is the big line on your bill — and it makes the most sense for homes near or above KSEB's 250-unit line, or about to cross it with an AC or an EV. Put your bill into the calculator; if it is early for you, it will say so.
Check your own bill- Two-month bill
- ₹300
- Units on it
- about 50
- Fixed charge + meter rent · stays
- ≈ ₹112
- What solar can remove · per bill
- ≈ ₹190
- Per year
- ≈ ₹1,100
- Pays for itself
- not in its lifetime
Worked with KSEB's 2025–27 domestic tariff — the same engine as our calculator.
Five questions that sort the quotes.
Will you put the full specification in writing?
Pipe section and thickness in millimetres, number and depth of earthing pits, cable brand and size, connector brand, surge-protector and breaker brands, fastener material. A quote that lists only "panels, inverter, structure" is telling you where the savings will come from.
Who is watching my roof in year six?
A roof fails quietly — output drifts down and nobody notices for a year. Ask who checks the generation, how often, and who comes when it drops. A commission agent usually cannot answer this, because he will not be there.
Are you sizing for the house I'll have, or the bill I have today?
Usage climbs after solar. An AC, an electric scooter or an induction hob can push a home past KSEB's 250-unit line, where every unit is billed at the top rate. Size for what is coming — our calculator lets you add it — rather than exactly for today.
What voids the warranties?
Every maker's warranty holds only when its guidelines are followed. A frame that flexes, a connector crimped with the wrong tool, a panel drilled instead of clamped — each one turns a thirty-year promise into physical damage, which is not covered. The installation is what keeps the warranty alive.
Does the subsidy come to me?
Under PM Surya Ghar the ₹78,000 is paid by the government directly into your bank account after commissioning. It never needs to pass through an installer. Be careful of any arrangement where you pay less now and hand over a cheque to be banked when the subsidy lands — that is how disputes start.
"It pains me to see people spend their savings on a roof that won't last — and get told it will. Don't waste your money on solar unless you study it first. If you do, you'll know a good quote when you see one, wherever you are."
Akhil Varghese
Founder · NRG Solutions · Wayanad
Where to go from here.
See every part we put on a roof, in the order it goes on — or put your own bill in and find out whether solar is early for you.