Calculate Your Solar Potential
Financing options, generation forecasts & detailed financial analysis
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Fill in your details to see detailed solar analysis
How to use this solar ROI calculator
Move the sliders for monthly bill, roof area, sanctioned load, and daytime usage to see how your recommended system size changes. The calculator estimates monthly generation, MNRE subsidy, payback period, and lifetime savings based on Tamil Nadu tariffs and typical sunlight. Switch between on-grid and off-grid to compare battery costs and backup value.
What the numbers assume
- Grid tariff of ₹8.15/kWh (average Tamil Nadu slab) and 300+ sunny days per year.
- 100–120 units/kW/month generation for unshaded roofs; we reduce this if you choose moderate/heavy shading.
- MNRE rooftop subsidy capped at ₹78,000 for homes; GHS/RWA up to 500 kW at ₹18,000/kW.
- Typical 25-year life for Tier-1 panels, with inverter swap factored into lifetime savings.
- Roof area to capacity at roughly 100 sq ft per kW with space for walkways and maintenance.
Tips to get accurate results
- Use your last 6 months of EB bills for an average monthly bill input.
- Select "moderate" shading if nearby trees or buildings block sun for 2–4 hours daily.
- Daytime consumption matters: a higher percentage favors on-grid without batteries for faster payback.
- For frequent outages, test the off-grid option to budget for batteries and backup hours.
- Add your PIN to help us suggest local net-metering timelines and DISCOM requirements.
Example scenarios
A 3 kW on-grid system for a ₹5,000 monthly bill home with minimal shade typically generates ~360 units/month, cutting EB bills by 60–80% with a 4–5 year payback after subsidy. A 5 kW hybrid system with batteries for a small business that needs backup during outages will cost more upfront but protects against downtime while still paying back in roughly 5–6 years because daytime loads consume most of the solar generation.
Farmers using 3 hp pumps can model 6–8 kW off-grid setups to cover watering hours; pairing solar with efficient pumps and timers reduces runtime and battery size. Apartments and RWAs can try the GHS/RWA option to see per-kW subsidy and common-area savings when elevators, pumps, and corridor lighting shift to solar during peak tariff times.
Financing and next steps
We support zero-cost EMI, bank loans, and channel financing. If you prefer cash-and-carry, the payback is faster; if you choose EMI, the monthly installment often stays below your previous EB bill. Use the "Show Results" button and share your details so our engineers can validate roof photos, check sanctioned load, and finalize a quote with subsidy paperwork and net-metering guidance.
Ready to move forward? Submit your contact info after running the numbers. We will call with a layout, bill reduction estimate, and a clear installation timeline for your area.
Quick checklist
- Recent EB bill and sanctioned load details
- Roof photos (north/south/east/west) for shading
- Preferred system type: on-grid vs hybrid/off-grid
- Backup hours needed during outages
- Any planned future loads: EV, AC, or pump upgrades
What happens after you submit
- We confirm your roof suitability, shadow profile, and feasible capacity.
- Our team shares a layout, components list, and subsidy checklist.
- Installation is scheduled with net-metering documentation and DISCOM liaison.
- You receive app-based monitoring, performance review, and maintenance plan.
Why trust these estimates?
We use conservative generation factors, include shading penalties, and cap subsidies to official limits. Actual output may vary with panel brand, inverter efficiency, tilt angle, and seasonal weather. Share your site details so we can fine-tune with satellite imagery and on-site survey data.
* Estimates based on typical Tamil Nadu conditions. Actual results vary by location, weather, maintenance & panel quality. Subsidies subject to eligibility. Contact us for accurate site assessment.