How to buy rooftop solar for your home in India

How rooftop solar works

For most homes in India, rooftop solar means an on grid system. Panels generate electricity during sunlight hours. Your home uses that solar power first. If generation is higher than your daytime load, the extra power is exported to the grid through a solar net meter. If generation is lower, you import power from the grid as usual.

This is why rooftop solar is mainly a bill reduction tool. It works best when your home has meaningful daytime consumption, a suitable roof, and a bill high enough to justify the investment. It does not mean your home is fully independent from the grid, and during a power cut, a standard on grid system typically shuts off for safety.

That is also why we tell homeowners to begin with three basic checks before comparing vendors: your average monthly bill, your daytime usage pattern, and your usable roof space. Without those three, most solar recommendations are guesswork dressed up as certainty.

1. Size by bill

The cleanest starting point is your monthly electricity bill. It is easier to verify than house type, and it usually reflects your real demand better. The mapping below is a practical approximation, not a guarantee. Final sizing still depends on roof area, daytime usage pattern, and future loads such as more ACs or an EV.

Treat the AC and EV examples as directional. Actual appliance support depends on AC tonnage, how many hours you run them, and whether those loads operate together or are staggered. A home with the same bill can need a different solar size if most use happens at night, or if a new EV charger is planned soon.

If your main goal is the fastest payback, avoid oversizing just for bragging rights. If your main goal is future readiness, a slightly larger system can be sensible. A good installer should explain that tradeoff openly instead of pushing the largest possible quote.

2. Compare system structure

Not every home needs the same physical layout. A standard rooftop install is often enough, but the right structure depends on space, accessibility, and how much of your terrace you still want to use. We usually frame the choice like this.

Floor mounted solar can make sense when the roof is small, access matters, and you want simpler cleaning and servicing. Elevated structures are useful when you want usable space below the panels. For larger homes, space efficient layouts can help balance generation with terrace utility instead of treating the roof as a dead surface.

The structural choice should follow fit, not fashion. If you are trying to preserve utility space, host daytime loads, and plan for future additions, ask each vendor to show how their design affects both generation and rooftop usability. That conversation reveals a lot about whether they are designing around your home or around a template.

3. Compare DCR and non DCR

This is where many buyers make the wrong assumption. We offer two panel types. DCR panels are subsidy eligible and use 600 Wp modules. Non DCR panels are not subsidy eligible and use 625 Wp modules, with a generally lower listed price. The right choice is not always the one that sounds most subsidised.

PM Surya Ghar subsidy is ₹30,000 per kW for the first 2 kW, plus ₹18,000 for the 3rd kW, capped at ₹78,000 total for systems 3 kW and above. That means the subsidy meaningfully lowers final customer cost on 3 kW to 6 kW systems. But after the cap is hit, bigger systems can change the comparison.

The genuine buying insight is simple. Up to 6 kW, DCR usually makes more sense because the subsidy reduces your final cost. At 8 kW, non DCR is actually cheaper even without claiming subsidy. So the common advice to always take the subsidy stops working once you move into larger system sizes.

That is exactly why quote comparison must focus on final payable amount, not just subsidy headlines. A serious solar company should be able to explain when subsidy helps, when it stops helping enough, and why your best fit may change at higher capacities.

4. Compare financing

Solar financing in India is straightforward in principle. Instead of paying the full amount upfront, you spread the cost through EMI. The real question is not whether EMI exists. The real question is whether the EMI still leaves room for net monthly savings, and whether the system payback remains reasonable.

Here is one practical example. A 3 kW DCR system costs ₹1,52,999 after subsidy. On a 12 month no cost EMI, the payment is about ₹12,750 per month. Solar typically offsets about 85% of the bill because fixed DISCOM charges still apply. So if your monthly bill is ₹3,000, it may drop to about ₹450, freeing up about ₹2,550 per month.

For many homeowners, that makes the short term cash flow decision obvious. Upfront payment usually gives the cleanest savings profile. EMI makes sense when you want to preserve liquidity, stage the investment, or avoid delaying the project. Typical post subsidy payback is 4 to 6 years, with 5 years being the most common outcome.

When you compare financing offers, look beyond the EMI number. Ask whether it is truly no cost, what tenure applies, whether approvals and installation are already included in the project price, and whether the quote still makes sense after factoring your likely bill reduction rather than unrealistic promises of a zero bill.

5. Compare service support

A rooftop solar purchase does not end at installation. Good buying decisions also account for approvals, subsidy support, commissioning, and long term maintenance. If a homeowner has to chase paperwork, DISCOM coordination, and service separately, the low headline price quickly loses its charm.

Ask who handles net metering and utility approvals, what documents you need to provide, and what happens if timelines slip. You should also ask what maintenance is expected after commissioning. Panels need periodic cleaning, especially in dusty urban conditions, and performance checks matter if you want your output to remain close to expectations over time.

For a first time buyer, this is one of the best trust tests. A strong installer will explain the installation process from site survey to grid connection in plain language, set expectations on what you must do versus what they handle, and give you a service path after the system goes live.

6. Shortlist the right company

If you are deciding which solar company to choose for your home in India, reduce the shortlist with a simple filter. First, check whether the company is MNRE approved or listed where relevant for subsidy linked work. Second, ask whether they manage approvals and net metering support. Third, compare system design logic, final pricing, and after sales clarity, not just the cheapest per kW number.

This is where we try to be useful. We do not think homeowners need more noise. They need a framework. If a company cannot clearly explain how rooftop solar works, what size fits your bill, how financing changes cash flow, and how subsidy really affects final price, it is hard to trust the rest of the proposal.

Use this framework on every quote you receive. Start with your bill, validate the structure, compare DCR against non DCR on final cost, check financing honestly, and make sure approvals and service are clearly owned. If you do that, you will buy solar with much more confidence and far fewer surprises.