Switching to solar is an increasingly savvy move for Indian homeowners in 2025. With electricity tariffs rising and reliable power still a concern in many areas, a rooftop solar array can lock in decades of “free” sunshine.
Government programs are booming – for example, the new PM Surya Ghar Muft Bijli Yojana has already helped 10 lakh homes go solar as of March 2025 [Source].
A 3.24 kW system is a popular mid-size choice, being large enough to power most appliances in a medium to large home while still being affordable.
In this guide, we’ll break down exactly what a 3.24 kW rooftop installation involves, how much it costs, what support you can get, and everything you need to know to make an informed decision.
What’s in a 3.24 kW Rooftop Solar System?
A 3.24 kW (KiloWatt) system means the panels can produce 3,240 watts during peak sun hours (ideal sunlight). In practical terms, that might require around 5-8 solar panels (depending on panel wattage) plus supporting equipment.
For example, one recent installation used six 540 W panels (totaling 3,240 W) paired with a 3 kW string inverter.
In general, a system includes:
- Solar panels (PV modules): These generate direct current (DC) electricity from sunlight. Modern panels are often 535–585 watts each, so ~6–9 panels make ~3.24 kW.
- Inverter: It converts the DC power from the panels into AC power for your home or the grid. A 3–4 kW inverter (e.g., Qbits Inverter) is typical.
- Mounting structure: Racks or frames (usually metal) that securely fix the panels to your roof at the correct tilt/angle.
- Wiring and protection: DC and AC cables, fuse boxes (DCDB/ACDB), and MC4 connectors to link panels. As per safety rules, you’ll also need earthing and lightning arrestors.
- Net meter: Most systems connect to the grid via a bi-directional meter (net meter), allowing you to export excess power.
In summary, a 3.24 kW kit typically includes the PV modules, inverter, mounting kit, wiring, and labor for installation.
System Cost Breakdown (Equipment + Installation)
The upfront cost of a 3.24 kW rooftop system can vary by region and the quality of components. As of 2025, a turnkey 3 kW solar installation in India typically runs ₹1.9–2.2 lakh (before subsidies).
This includes panels, inverter, structure, wiring, and labor. For example, industry estimates place a 3 kW home system at approximately ₹1.89–2.15 lakh, or roughly ₹75–85 per watt installed. (High-quality panels and inverters may push costs higher, while simpler setups can be on the lower side.)
Payback
The good news is that you recoup this investment relatively quickly. Given current tariffs, homes with strong sun exposure often recover their system cost in about 6–8 years through electricity savings.
In other words, after this payback period, you effectively get nearly free power for the remaining 15–20 years of panel life. (Actual payback depends on your electric rate, usage, and shading factors, but 6–8 years is a typical estimate)
Government Subsidies and Policies
The Indian government strongly supports the adoption of rooftop solar. Under the MNRE residential rooftop scheme (Phase II), a central subsidy (CFA) of ₹14,588 per kW is available for the first 3 kW of capacity. That means a roughly ₹43,764 subsidy for a 3 kW system (approximately ₹45–46k for a 3.24 kW system if pro-rated).
For capacities above 3 kW (up to 10 kW), the subsidy decreases to ₹7,294 per kW for the additional portion. Above 10 kW, a fixed ₹94,822 is offered.
In addition to the central CFA, many states offer their own incentives or zero-interest, low-interest loans for rooftop solar. Most recently, the Pradhan Mantri Surya Ghar: Muft Bijli Yojana (launched in January 2024) offers additional aid for middle/low-income households.
Under Surya Ghar, qualifying homes consuming over 300 units/month get a flat ₹78,000 subsidy if they install over 3 kW (Homes consuming 150–300 units/month get ₹60k to 78k for 2–3 kW systems)
In short, between central and PM Surya Ghar support, a homeowner can effectively slash ₹60–80k or more off a 3–4 kW system.
In addition to subsidies, the scheme has simplified the approval process. You apply via the national portal (or state DISCOM site), pick an empanelled vendor, and pay the subsidy directly to the vendor’s bank account upon commissioning.
Loans of up to ₹2 lakh (collateral-free, with an interest rate of ~7%) are also available for systems of up to 3 kW. These policies are why rooftop solar has taken off: As of March 2025, 10 lakh homes were powered by Surya Ghar, with free electricity essentially provided to beneficiaries. (By 2026-27, the goal is 1 crore homes.)
Installation Process and Timeline
Installing a rooftop system is straightforward but involves several steps. A typical process is:
- Site inspection: A registered solar vendor visits your home to assess the roof area, tilt, direction, and shading. They then finalize the panel layout and inverter size.
- System design: The vendor provides a proposal (including panels, inverter specifications, wiring plan, and estimated generation) along with a quote.
- Applications: You apply for net metering through your distribution company (DISCOM) or state portal. The vendor submits technical details and receives approval (usually within a few days to one week). They also handle local permits (most places waive major building permits for rooftop solar systems).
- Procurement: Once permissions are in place, the components are ordered (often shipped quickly if using domestic panels and inverters).
- Installation: Mounting rails and panels are fixed on the roof, inverter and wiring are installed, and the utility sets a new bi-directional (net) meter.
- Commissioning: The system is checked (voltage, earthing, safety), and then turned on. An inspector from the DISCOM may visit to verify the setup.
- Subsidy & Final Payments: After commissioning, you pay the remaining balance to the vendor (subsidy is transferred directly). The vendor or you can then activate the net metering to export any excess power.
Timeline: From the first survey to power-on, it typically takes 2–4 weeks in most urban areas (assuming paperwork goes smoothly). The national portal streamlines approvals (about a 15-day subsidy processing is promised). Once live, your panels start generating immediately.
Expected Generation, Bill Savings, and ROI
A 3.24 kW solar plant in India can generate roughly 300–350 units (kWh) per month on average (this varies by location and season). For example, the government’s program notes that “a 3-kW system can generate over 300 units per month”. In most parts of India, you receive 4–5 hours of sunlight per day, so 3.24 kW × ~4.5 hrs × 30 days ≈ 4,300 kWh/year. At ₹7–8 per kWh retail, that’s about ₹30,000–35,000 saved annually on your bill (plus any income if you export power).
Savings really add up: over 25 years (typical panel life), you’ll produce over 100,000 kWh. The Surya Ghar program estimates a 3 kW rooftop would generate ~1000 billion units nationwide over decades, massively cutting carbon emissions. For your home, even if you use only 10–15 kWh per day, a 3.24 kW plant can cover most daytime loads (fans, lights, TV, fridge, etc.). Any surplus is credited back to the grid (net metering).
Return on Investment: With ₹30k/year saved, a ₹2 lakh system pays for itself in under 7 years. Our sources agree that – the average residential payback is around 6–8 years. After that point, you effectively enjoy near-zero electricity bills for many more years. (With rising grid tariffs, ROI gets even better over time.) In simple terms, each kW installed yields roughly 320–350 units per month, or ₹2,500–3,000 in savings; scale that by 3.24 kW to estimate the offset on your bills.
3.24 kW vs. Other System Sizes
How do you know 3.24 kW is right for you? It’s useful to compare common sizes:
- 1 kW: Suitable only for very light use (e.g., a few lights, fans). Generates ~100–120 units per month. It may only cut a small portion of the bill.
- 2 kW: Small households (1–2 people) with mostly daytime usage. Approximately 200–240 units per month.
- 3.24 kW: A medium-to-large family (3–5 members) with typical appliances. Approximately 300–350 units per month. It can offset most household usage during the day and significantly reduce nighttime bills. This size hits a sweet spot for many 3–4 BHK homes.
- 5 kW: For large families or homes with heavy loads (air conditioning, electric heaters, electric vehicles, etc.). ~500+ units/month. It is more expensive (₹3.2–3.6 lakh for 5kW) but covers almost all consumption.
People often choose 3.24 kW because it’s big enough to make a noticeable dent in their bills while still qualifying for a full subsidy on 3 kW (and only slightly over). It’s also under many rooftops’ practical panel limit (usually 10–12 panels). If your consumption is high (e.g. ≥15,000–20,000 units/year) you might opt for 5 kW, but for a typical household, 3–4 kW is usually ideal. In summary, 3.24 kW gives a balance of cost, roof space, and output for most Indian homes.
Common Mistakes and Misconceptions
When buying rooftop solar, homeowners sometimes stumble on a few pitfalls:
- Choosing purely by price: The cheapest quote may use poor-quality panels or inverters that underperform or fail early. Always compare brands and certifications, not just rupees per watt.
- Ignoring roof issues: If your roof has shading (trees, buildings) or is too flat or too steep, solar generation drops. Don’t skip a proper site survey. Consider panel orientation (south-facing is best) and tilt (usually 15°–20° in India).
- Overestimating output: Some salespeople promise unrealistically high generation. Remember the average of ~4–5 peak sun hours per day. Claims like “500 units per month from 3 kW” are on the high side. Use calculators or installer data for a realistic estimate.
- Neglecting net-metering rules: Don’t assume you can export unlimited power. Check your state’s net-metering policy – some have monthly credits, others annual reconciliations, and rules on capping system size. Ensure the system size and meter type comply with these rules.
- Skipping maintenance: Solar needs minimal upkeep, but panels do need occasional cleaning (especially in dusty areas). Account for cleaning or maintenance schedules. Failing to do so can result in a 10% or more reduction in output over time.
- Not securing warranties: Ensure you get written warranties (see next section). Some consumers skip formal contracts, which is a risky move. Always document every term with the installer.
By being aware of these, you can avoid surprises and maximize the benefits of your solar investment.
Choosing an Installer and What to Expect
A great installer makes all the difference. Here’s how to choose wisely:
- Look for experience and accreditation: Pick an installer empanelled with MNRE/your state DISCOM or listed on the national portal. Check if they have installed many residential systems (ask for references or reviews).
- Component quality: Choose reputable panel brands (e.g., Adan, Waaree) and inverters (e.g., Qbits, ABB, Schneider, Luminous). Better components last longer and often have stronger warranties.
- Warranties and Service: Standard warranties typically cover 25 years for panel performance (guaranteed to maintain ~80% output at 25 years) and 5–10 years for the inverter. Confirm these in writing. Also, ask about on-site support: good installers offer a free maintenance visit once a year or have rapid-response service for any issues.
The installer should also guide you through the paperwork; many now complete the subsidy and net-meter application for you. A reliable vendor will assist with registering on the national portal, managing approvals, and liaising with the DISCOM during commissioning. In short, pick someone who makes the process easy and stands behind their work.
Final Tips
Talk to neighbors or local solar users to hear their experiences. Check your monthly usage to right-size the system. Keep an eye on the electricity bill credits once your system is on. And remember, solar energy also boosts your home’s value and reduces its carbon footprint – it’s a win-win for your wallet and the planet. By doing your homework now, you’ll power your home with sunshine for decades and save thousands of rupees. Embrace the solar future – it’s brighter than ever!