Solar Panel & Energy Savings Calculator

How Does This Solar Panel Calculator Work?

This tool estimates your solar energy requirements using your current electricity consumption as the baseline. Your monthly bill is divided by the electricity rate per kWh to determine your monthly consumption in kWh. This is then divided by the average 4.5 peak sun hours per day (a conservative global average for most of India) and 30 days to arrive at the required solar system capacity in kilowatts (kW).

The number of solar panels is calculated assuming standard 400-Watt monocrystalline panels — the current industry standard for residential installations. The annual savings estimate assumes the solar system offsets your entire electricity bill, which is typical for correctly sized grid-tied systems.

Understanding Solar System Components

A complete rooftop solar installation comprises four main components:

• Solar Panels (PV Modules): Convert sunlight into DC electricity. Modern monocrystalline panels achieve 20–23% efficiency. A 400W panel is approximately 1.7m × 1.0m in size. Most residential rooftops in India receive 4–6 peak sun hours per day depending on location.
• Solar Inverter: Converts DC electricity from the panels into AC electricity usable by your home appliances. For grid-tied systems, the inverter also synchronises with the grid frequency. String inverters are most common; microinverters (one per panel) offer better performance under partial shading.
• Mounting Structure: Galvanised or aluminium racking that secures panels to the roof at the optimal tilt angle (typically 15–25° in India, matching the local latitude).
• Grid Connection / Net Meter: For grid-tied systems, a bidirectional net meter measures the difference between solar generation and household consumption. Surplus electricity is exported to the grid and credited to your account at a rate determined by your state's DISCOM (electricity distribution company).

Solar Energy in India: Government Subsidies (2026)

The Indian government provides significant subsidies for residential rooftop solar under the PM Surya Ghar: Muft Bijli Yojana scheme (launched February 2024), which replaced the earlier PM Kusum scheme:

• Systems up to 2 kW: 60% subsidy on the benchmark installation cost set by MNRE.
• Systems of 2–3 kW: 60% subsidy on the first 2 kW, 40% subsidy on the additional capacity.
• Systems above 3 kW: Subsidy capped at the amount applicable for a 3 kW system.
• The scheme also provides collateral-free loans at concessional rates through nationalised banks for the unsubsidised portion.

As a rough benchmark, a 3 kW system costs approximately ₹1.5–₹2 lakhs after subsidy, and can generate 350–400 units of electricity per month in most Indian cities.

Solar Panel Payback Period in India

The payback period — the time for your solar savings to recover the initial investment — depends on your electricity rate and system cost. For a typical urban household paying ₹8–₹10 per unit consuming 300–400 units/month:

• System cost after subsidy: ~₹1.5 lakhs (3 kW system)
• Monthly savings: ~₹2,500–₹3,500
• Payback period: 4–5 years

Solar panels have a guaranteed output warranty of 25 years, so after payback, you enjoy 20+ years of essentially free electricity — making solar one of the highest-return investments available to Indian homeowners.