NoteMide India rooftop solar planning tools
Rooftop Solar Panel Calculator India
Estimate a preliminary rooftop solar system for an Indian home, apartment, business, or industrial site. Start with a typical monthly electricity bill, State or Union Territory, customer category, and an editable electricity cost per unit. Add usable roof area, panel wattage, and a target bill offset to see an indicative system size, panel count, generation, cost, residential central-assistance context, savings, and simple payback.
How the rooftop solar estimate works
The calculator converts a typical monthly bill into an approximate monthly unit figure using the editable planning tariff. It then compares target annual generation with an indicative roof-area limit and uses selected panel wattage to estimate panel count. Generation and cost values are planning assumptions, not a site survey, installer quote, or guaranteed production statement.
State source registry and verification dates
The interactive registry lists all Indian states and Union Territories, the starting national or local source, a local verification note, and a last-verified date. PM Surya Ghar is the starting national residential-assistance source. A registry row does not promise an extra state subsidy, net-metering approval, or eligibility. Confirm the live policy, DISCOM process, sanctioned load, approved vendor and current notification before applying or paying a vendor.
Example official starting points include the PM Surya Ghar National Portal, the Delhi Solar Portal, and Telangana TGREDCO rooftop policy. The registry was last reviewed on 4 November 2026.
Frequently asked questions
How much solar subsidy can a home receive?
The PM Surya Ghar national portal currently describes central assistance of ₹30,000 per kW for the first 2 kW and ₹18,000 for the third kW, with a maximum residential central assistance of ₹78,000 for systems above 3 kW. This calculator shows only an estimate. Confirm current eligibility, caps, approved vendors, commissioning and disbursement through the official portal.
Does every state provide an additional solar subsidy?
No. State or DISCOM programmes can differ by consumer category, budget, notification date and application route. Check the state or Union Territory source registry and confirm the current policy with the utility serving your address.
How many solar panels do I need for a ₹4,000 bill?
There is no single answer because a bill includes tariff slabs, fixed charges and taxes. As a simple example, ₹4,000 at ₹8 per unit is about 500 units per month. An 80% offset with an illustrative 1,200 units per kW-year assumption points toward roughly 4 kW, which could mean about 8 panels at 550 W.
How much roof area is needed?
The calculator uses approximately 100 square feet per kW as an early planning assumption. Actual requirements depend on panel dimensions, orientation, shade, access paths, parapets, inverter location and structural safety.
Can solar panels make my electricity bill zero?
Not necessarily. Fixed charges, taxes, minimum charges, demand charges and export settlement may remain. Net-metering rules differ by state, DISCOM, system size and consumer category.
What is net metering?
Net metering is a grid arrangement in which a bidirectional meter records electricity imported from and exported to the grid under the applicable regulation. The approval, capacity, settlement period, meter process and charges depend on the state regulator and DISCOM.
Is net metering available for every customer?
Availability and conditions are not universal. Residential, RWA, commercial and industrial connections may have different rules, and local transformer capacity or sanctioned load can affect approval.
Does the calculator include batteries?
No. This is a preliminary grid-connected rooftop estimate. Batteries change system cost, self-consumption, backup capability, replacement planning and payback.
Is the result an installer quote or subsidy approval?
No. It is planning math based on editable assumptions. A qualified installer or engineer must verify the roof, equipment, generation, approvals, net metering, taxes, warranties, final price and subsidy eligibility.
Which checks should I complete before applying?
Confirm the consumer category, latest electricity bill, sanctioned load, documents requested by the official portal, approved vendor status, roof feasibility, net-metering process and the current policy notification.
Read the ₹4,000 bill panel-count guide · Read the state subsidy guide · Read the calculation methodology