Solar System Size for Home Under PM Surya Ghar 2026: 1kW, 2kW, 3kW or More?

Official PM Surya Ghar Consumption and Capacity Bands

Government consumer guidance provides a useful first shortlist. It does not replace a site-specific calculation.

Eight-Step Home Solar Sizing Process

1. Collect 12 consecutive electricity bills and record monthly units, not only bill amounts.
2. Remove unusual temporary consumption and note seasonal high and low months.
3. List appliances that run during solar-generation hours and those used mainly at night.
4. Add realistic future demand such as air conditioning, electric cooking, water heating, pumps, work-from-home equipment or an electric vehicle.
5. Measure usable unshaded roof after allowing for access, parapets, tanks, drainage and maintenance.
6. Use the official rooftop calculator for location-specific generation and financial analysis.
7. Ask registered vendors to quote at least two nearby capacities using the same module, inverter, structure and service scope.
8. Select the capacity that balances consumption coverage, direct self-use, roof, approved metering, project cost, subsidy and financing.

How to Analyse Twelve Months of Electricity Bills

Twelve months are better than one recent bill because household demand often changes with summer cooling, monsoon humidity, winter heating, school holidays, guests and water-pump use.

Why Daytime Electricity Use Changes the Best Size

Solar electricity used immediately inside the home can reduce grid import directly. Surplus electricity is exported and settled according to the State-approved net metering, net billing or other arrangement. Direct consumption and export may not have equal financial value.

Review import, export and settlement through the PM Surya Ghar net-meter guide .

Add Future Appliances Before Finalising Capacity

A rooftop plant can operate for many years, so a system sized only for today may become too small soon. Add only planned and financially realistic loads.

Roof Area and Shade Can Set the Maximum Practical Size

A household may need 3kW from its bills but have safe, unshaded space for less. Conversely, a large roof does not justify installing more capacity than the consumption and financial plan support.

• Use unshaded roof area, not the total built-up area.
• Check shadows in different seasons and times.
• Allow walkways for cleaning and inspection.
• Keep access to water tanks, drains and roof repairs.
• Assess structural loading and anchoring.
• Plan module row spacing and tilt.
• Choose a protected and ventilated inverter location.
• Plan cable routes before final pricing.
• Account for parapet and nearby-building shade.
• Obtain owner, co-owner, landlord or RWA permission where needed.

How to Use the Official PM Surya Ghar Rooftop Calculator

The National Portal Knowledge Centre describes the rooftop calculator as a tool for feasibility and financial analysis. Use it after preparing realistic bill and roof inputs.

1. Select or enter the installation location requested by the current calculator.
2. Enter electricity use, tariff or bill information using normal values rather than one unusual month.
3. Review the system capacity and generation estimate for the location.
4. Compare at least two capacities, such as 1kW versus 2kW or 2kW versus 3kW.
5. Check whether the estimated project cost matches current itemised vendor quotations.
6. Replace assumed tariff, export value or finance inputs with the current local figures where possible.
7. Save the result as a planning document, not as a guarantee of approval or generation.

Simple 1kW, 2kW, 3kW or Larger Decision Tree

Home Solar Capacity Comparison

When a 1kW System Makes Sense

Review price and subsidy through the 1kW PM Surya Ghar cost guide .

When a 2kW System Makes Sense

Review project cost through the 2kW PM Surya Ghar cost guide .

When a 3kW System Makes Sense

Review the third-kilowatt cost through the 3kW PM Surya Ghar cost guide .

When a System Above 3kW Makes Sense

High-use households can install more than 3kW when the roof, connection, metering and financial plan support it. The standard household CFA remains capped at ₹78,000, so additional capacity must be justified without extra central subsidy.

• Normal consumption is consistently above 300 units per month.
• Future EV, cooling, cooking or heating demand is documented.
• The roof safely accommodates the larger array.
• Connection and phase requirements are confirmed.
• The State settlement method gives reasonable value to expected export.
• The household can finance the unsubsidised extra capacity.
• The vendor provides a generation and cash-flow comparison for 3kW and the larger size.

Review current load and utility actions in the PM Surya Ghar feasibility and load guide .

Risks of Oversizing the Rooftop System

• More upfront cost without additional CFA beyond 3kW.
• Large daytime surplus may receive lower value than direct self-consumption.
• Roof becomes crowded and difficult to maintain.
• Additional structure or electrical upgrades raise project cost.
• Vendor generation assumptions may exceed realistic site output.
• Loan EMI may remain higher than actual monthly savings.
• Future tariff or export-rule changes can alter economics.
• The consumer may purchase a battery merely to absorb unnecessary surplus.

Risks of Undersizing the Rooftop System

• Large grid imports continue even when more safe roof area was available.
• Future appliances quickly consume all planned generation.
• Fixed installation and metering costs are spread over fewer solar units.
• Expansion later may require a new inverter, structure, approval or vendor visit.
• Existing subsidised systems can claim only eligible balance up to the total 3kW CFA ceiling.
• A smaller inverter or cable design may complicate future expansion.

How Subsidy Changes the Capacity Decision

The complete rates and edge cases are explained in the PM Surya Ghar subsidy calculation guide .

How a Solar Loan Changes the Sizing Decision

Financing can make a larger system affordable upfront, but the borrower must compare EMI and total interest with conservative electricity savings.

• Use the final itemised quotation, not an advertised net price.
• Calculate EMI before assuming subsidy credit.
• Keep paying EMI until the lender posts CFA and revises the schedule.
• Include fees, insurance and benchmark-rate changes.
• Compare a smaller cash purchase with a larger financed system.
• Keep an emergency EMI reserve.
• Do not finance battery or premium extras without a specific need.

Review financing through the PM Surya Ghar solar-loan guide , and track CFA adjustment through the subsidy-payment status guide .

Questions a Vendor Must Answer Before Recommending Capacity

• Which twelve bills were used in the calculation?
• What monthly and annual consumption was assumed?
• Which future appliances were included?
• How much output is expected from the specific location?
• What shade and system-loss assumptions were used?
• How much generation will be directly consumed versus exported?
• What roof area and module layout support the proposal?
• What is the comparison with the next smaller and larger capacity?
• What current DISCOM metering and export rules were assumed?
• What is the project cost before CFA?
• What subsidy amount is expected from actual module capacity?
• What changes if consumption is 20% lower or higher than expected?

Select and compare installers using the registered-vendor guide .

Final Home Solar Sizing Worksheet

After selection, follow the online application process , prepare the required documents , and track installation through the PM Surya Ghar application-status guide .

Frequently Asked Questions

Choose Capacity With Evidence, Not a Sales Package

The correct home solar size is not simply the largest system that fits the roof or receives the highest subsidy. Begin with the official consumption band, then test it against twelve bills, daytime use, future demand, shade, safe roof layout, location-specific generation, metering value and final project cost.

Keep the complete PM Surya Ghar guide available, confirm the load process through the feasibility and approval guide , and use only a registered vendor for an eligible CFA-supported installation.