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Solar Suite

Solar Panel ROI & Payback Calculator

Calculate upfront capital needed, national PM Surya Ghar subsidy grants, annual savings, and net payback years.

Live 2026 Data
Payback Period 2.5 - 4.0 Years
IRR Return 25% - 35% Annualized
25-Year Savings Up to ₹8,00,000
Asset Class Low-risk Green Asset

1. Enter Configuration Parameters

Frequently Asked Questions (FAQ)

What is the average payback period for residential solar in India?

Typically, residential rooftop solar systems in India recover their initial net costs in 4 to 5 years. After this payback window, the electricity generated is essentially free for the remaining 20+ years of panel service life.

What is the cash subsidy for rooftop solar under PM Surya Ghar Yojana?

The central government provides a direct subsidy of Rs. 30,000 per kW for the first 2 kW of solar capacity, and Rs. 18,000 for the 3rd kW. The maximum subsidy is capped at Rs. 78,000 for any residential installation of 3 kW or higher.

How much roof space is required to install a 3 kW solar system?

A 3 kW residential solar system requires approximately 250 to 300 square feet of shadow-free rooftop space. Each solar panel is roughly 20 square feet, and a 3 kW setup typically uses 6 to 8 high-efficiency monocrystalline panels.

How many units of electricity does a 1 kW solar panel generate daily?

In India, a 1 kW solar plant generates an average of 4 to 4.5 kWh (units) of electricity per day in standard sunny conditions. This translates to roughly 120 to 135 units per month, or 1,500 units annually per kW of installed capacity.

What is solar net-metering, and how does it work?

Net-metering uses a bidirectional meter to record both the power you import from the grid and the excess solar power you export to the grid. At the end of the billing cycle, your DISCOM bills you only for the net units consumed (Import minus Export).

What is the typical ROI payback period for residential solar in India?

With the PM Surya Ghar subsidy, the net out-of-pocket cost for a 3 kW solar system is roughly Rs. 70,000 to Rs. 90,000. Generating Rs. 30,000 worth of free power annually, the system pays for itself in 2.5 to 3 years, followed by 22+ years of free power.

Does a grid-tied solar system work during power outages?

No. Standard grid-tied solar systems automatically shut down during a power cut for safety reasons (anti-islanding) to protect utility workers repairing the lines. To run appliances during power outages, you need a hybrid solar system with battery backup.

About This Calculator

Target Audience: Property owners exploring solar ROI, panel sizing & government subsidy benefits

What Does This Calculator Do?

This calculator estimates the payback period (ROI) and 25-year cumulative savings of installing a rooftop solar plant for your home. It automatically incorporates the government's PM Surya Ghar Muft Bijli Yojana subsidy.

How to Use It

  1. Solar Plant Size: Enter capacity in kW (typically 1 kW to 10 kW).
  2. Monthly Electricity Bill: Enter your current average monthly electricity bill.
  3. Project Cost: Enter the contractor quote or use standard rates (e.g., ₹60,000/kW).

The Logic Explained Simply

  • The Concept: Rooftop solar panels generate free electricity, cutting your monthly bill. The government offsets the initial cost with a direct subsidy. Over time, your accumulated bill savings fully pay back the investment, after which the power generated is pure profit.
  • The Formula:
  • Net Initial Cost = Total Project Cost - PM Surya Ghar Subsidy
  • Annual Solar Generation = Plant Size (kW) × 4.5 Peak Hours × 365 Days × 0.8 System Efficiency
  • Payback Period (Years) = Net Initial Cost / Annual Savings

Real-World Calculation Breakdown

For a 3 kW Solar System costing ₹1,80,000 in India:

  1. Subsidy: ₹78,000 (Maximum subsidy for 3 kW).
  2. Net Initial Cost: ₹1,80,000 - ₹78,000 = ₹1,02,000.
  3. Generation: 3 kW × 4 units/kW/day × 365 = ~4,380 units/year.
  4. Annual Savings: 4,380 units × ₹7.00/unit tariff = ₹30,660.
  5. Payback Period: ₹1,02,000 / ₹30,660 = 3.32 years.
  6. 25-Year Net Profit: Over ₹6,50,000 in free power!

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