Calculate ROI on Solar: A Step-by-Step Guide

Switching to solar energy is a significant investment, but its long-term benefits often outweigh the initial costs. One of the most compelling aspects of adopting solar power is the return on investment (ROI) it provides. If you’re wondering how to calculate ROI on solar, this step-by-step guide will help you determine the financial viability of your solar power system.

Understanding ROI in Solar Investments

ROI, or return on investment, measures the financial gains relative to the cost of an investment. In the context of solar energy, ROI assesses how quickly your solar power system pays for itself through savings on electricity bills and additional benefits, like government incentives. Knowing how to calculate ROI on solar ensures you make an informed decision about going solar.

Steps to Calculate ROI on Solar

1. Determine the Total Cost of Your Solar System

The first step is to calculate the upfront cost of your solar installation. This includes:

  • The cost of solar panels.
  • Installation fees.
  • Accessories like inverters and batteries.
  • Maintenance plans (if applicable).

For example, if your total installation cost is ₹2,00,000 (approximate cost for a 3kW system), this figure becomes the baseline for your calculations.

2. Calculate Annual Electricity Savings

To estimate your savings, review your electricity bills to find your average annual consumption and the cost per unit (kWh).

  • Multiply your annual usage (in kWh) by the cost per unit.
  • Estimate how much of this consumption will be offset by solar power.

For instance, if you use 6,000 kWh annually at ₹7 per unit, your yearly electricity expense is ₹42,000. A solar system that offsets 90% of your consumption will save ₹37,800 annually.

3. Factor in Government Incentives and Rebates

Many governments offer subsidies, tax credits, or rebates for installing solar panels. Include these in your ROI calculation to reduce the effective cost of your system.

  • With a subsidy of ₹78,000, your net cost becomes ₹1,22,000.

5. Calculate Payback Period

The payback period is the time it takes to recover your initial investment through savings. Use this formula:

Payback Period (years) = Net System Cost / Annual Savings

For a net cost of ₹1,22,000 and annual savings of ₹37,800, the payback period is approximately 3 years.

6. Calculate ROI on Solar

To calculate the ROI on solar, use this formula:

ROI (%) = (Lifetime Savings – Net System Cost / Net System Cost)×100

Assume your solar system lasts 25 years and generates savings of ₹9,45,000 (₹37,800 × 25).

Subtract the net cost (₹1,22,000) to get ₹8,23,000. Then:

ROI (%) = (8,23,000 / 1,22,000) × 100 = 278%


This means your investment returns nearly three times its cost over the system’s lifespan.

Benefits of Calculating ROI on Solar

  1. Financial Clarity: Understanding ROI helps evaluate the financial feasibility of solar adoption.
  2. Long-Term Savings: Calculate how much you save in electricity costs over time.
  3. Environmental Impact: Solar power reduces your carbon footprint while generating financial returns.

Additional Considerations

While ROI is a vital metric, also consider the following:

  • Energy Tariff Increases: Rising electricity prices enhance your savings.
  • Battery Storage: Adding batteries increases upfront costs but boosts energy independence.
  • Property Value: Solar installations can increase your home’s resale value.

If manual calculations feel tedious, try the Solar Rooftop Calculator. It simplifies everything—just input simple details, and it calculates the setup for you!

Final Thoughts

Calculating ROI on solar is essential for making an informed decision about adopting solar energy. By understanding the upfront costs, long-term savings, and additional benefits, you can evaluate how solar power fits into your financial goals. Use this guide to calculate ROI on solar and take a step toward a greener, more cost-effective future.

Stay tuned to our blog for more informational content. Get in touch with ZunRoof for expert solar consultation free of cost.