Nobody's roof does 1,650.
That is the generation figure every rooftop solar quote in this city is built on, and it is the number before a single loss is taken off. Ours measured 1,392 across 214 systems we still monitor. Everything on this site is built from the second number.
The sky over Ahmedabad. Centre is overhead, rim is the horizon, three arcs are the solstices and the equinox.
A quote will tell you 3.7 years. We will tell you 4.2.
Same 3 kW system, same ₹78,000 subsidy, same 350-unit bill. The difference is dust, heat, ageing, a water tank in the south-west, and the fact that units you export and do not use are settled at ₹2.25 rather than at your tariff. All measurable. All left out of a standard quote.
What we would tell you
Numbers a solar company is not supposed to publish.
Systems installed
Since 2017, 4,620 kW in total across Ahmedabad and Gandhinagar.
Median subsidy wait
From commissioning to the credit landing. Worst case in that period was 148 days.
Roofs we turned down
Too shaded, wrong roof, or the consumer wanted a size the connection would not carry.
Year-one yield, measured
Median across 214 systems commissioned in 2023 that we still monitor. The brochure figure for this city is 1,650.
Inverter failures
Out of 1,148 systems, all replaced under warranty. Two took more than a month because the brand had no Gujarat stock, which is why we stopped selling that brand.
Every deduction, in order, with nothing hidden in a footnote.
1,366 kWh per kW, before your roof's own shading and before any ageing. Our measured median across 214 monitored systems is 1,392 kWh/kW — close enough to this that we are comfortable quoting from it, and 16% below the number you will see on a pamphlet.
Including the sentence that sells most rooftop solar in India.
We will not quote you a three-year payback
It is the standard claim in this trade and it requires ignoring soiling, degradation, the fact that you are out of the house at noon, and the rate at which surplus is actually settled. Our honest number for a typical Ahmedabad household is between four and a half and five and a half years. That is still a good investment. It is just not the one on the pamphlet.
Solar will not run your house in a power cut
A grid-tied system shuts down when the grid goes down — it has to, or it would electrocute the lineman. If you want backup you need batteries, and batteries roughly double the cost while adding almost nothing to the savings. We will quote it if you ask. We will also tell you it ruins the payback.
We will not oversize past your sanctioned load
The DISCOM approves capacity against the load sanctioned on your connection. A vendor who sells you 8 kW on a 4 kW connection has sold you a rejection, or an application to raise your load that they did not mention.
We will not install on a roof with more than 20% shading loss
We have walked away from 63 roofs since 2017 for this reason. Panel-level optimisers help at the margin, and they are also the standard upsell used to sell a system that should not be there.
We will tell you on the roof if this is a bad idea.
Free, about ninety minutes, compass and inclinometer, and we read your last six bills. We have walked away from 63 roofs since 2017 and we would rather make it 64 than sell you something that does not work.