February 28, 2026 / Solar Panel

1kW vs 3kW vs 5kW: Which Solar Size Is Right for Your Home?

One of the most common questions homeowners ask before installing rooftop solar is: 

Which solar system size is right for my home: 1kW, 3kW, or 5kW? 

Choosing the correct system size is critical because: 

A. Oversizing increases unnecessary investment 

B. Under sizing limits savings 

C. Proper sizing optimizes ROI

 

For Indian households, selecting the best solar system size for home in India depends on electricity consumption, roof space, budget, and future energy needs. 

Let’s compare 1kW vs 3kW vs 5kW solar systems in detail.

Understanding Solar System Capacity

Solar system capacity is measured in kilowatts (kW). It indicates the maximum power the system can generate under ideal sunlight conditions. In India, on average: 

1 kW solar system generates- 

1. 4–5 units per day

2. 120–150 units per month

3. 1,400–1,800 units per year 

Actual generation depends on- 

1. Location

2. Tilt angle

3. Shading

4. System quality 

This helps estimate your ideal rooftop solar size.

Calculate your Monthly Electricity Consumption

Check your electricity bill. Average Indian household consumption: 

1. Small home (1–2 BHK) → 100–200 units/month

2. Medium home (2–3 BHK) → 250–400 units/month

3. Large home (3–4 BHK with ACs) → 500+ units/month 

Your monthly usage determines whether a 1kW, 3kW, or 5kW system fits best.

1 kW Solar System: Who is it Suitable for?

Ideal For: Small homes, Low electricity usage, Rural homes, and Limited roof space 

Generation: 120–150 units per month 

Space Required: 80–100 sq. ft. 

1kW Solar System Price in India: Approximately ₹50,000–₹75,000 

Advantages: 

1. Low upfront investment

2. Quick installation

3. Suitable for basic appliances 

Limitations: 

1. Not suitable for heavy loads

2. Limited AC usage coverage 

Best for households consuming below 150 units per month.

3kW Solar System for Homes: Most Popular Choice

Ideal For: Medium-sized families, 2–3 BHK homes, and Homes with 1–2 air conditioners 

Generation: 350–450 units per month 

Space Required: 250–300 sq. ft. 

Estimated Cost: ₹1.5–2.2 lakh (before subsidy) 

Benefits: 

1. Covers most residential loads

2. Significant electricity bill reduction

3. Good balance between cost and savings 

A 3kW solar system for home is currently the most installed residential size in India.

5kW Rooftop Solar System: for High Consumption Homes

Ideal For: Large homes, Multiple AC units, Electric vehicle charging, and High daytime consumption 

Generation: 600–750 units per month 

Space Required: 400–500 sq. ft. 

Estimated Cost: ₹2.5–3.5 lakh (before subsidy) 

Benefits: 

1. Covers high monthly bills

2. Faster solar payback period India

3. Future-ready capacity 

A 5kW rooftop solar system is ideal for households consuming 500+ units monthly.

Solar System Cost Comparison in India

System Size 

Monthly Units Generated 

Approx. Cost 

Suitable For 

1kW 

120–150 

₹50k–₹75k 

Small homes 

3kW 

350–450 

₹1.5–2.2L 

Medium homes 

5kW 

600–750 

₹2.5–3.5L 

Large homes 

Costs vary by state and configuration. 

Solar Subsidy for Residential Rooftop Segment- 

Under central government schemes like PM Surya Ghar: 

1. Subsidy is available for residential rooftop solar

2. Subsidy amount depends on system size

3. Only eligible and compliant systems qualify 

This reduces effective installation costs.

Hybrid Solar Systems for homes: Should you add batteries?

If your area has: 

1. Frequent power cuts

2. Voltage fluctuations 

A hybrid solar system with battery backup may be useful. However, for stable grid areas, on-grid systems with net metering are often sufficient. 

Should You Oversize? 

Consider: 

1. Adding more ACs

2. Buying an electric vehicle

3. Increasing household members 

If expansion is likely, a slightly larger system may provide better long-term value.

How to use Solar System Capacity Calculator?

Professional installers assess: 

1. Past 12 months electricity consumption

2. Roof orientation

3. Shadow analysis

4. Budget

5. Future expansion 

This ensures accurate sizing. 

Payback Period Comparison- 

Approximate residential payback: 

1. 1kW → 4–5 years

2. 3kW → 3–4 years

3. 5kW → 3–4 years (depending on usage) 

Higher consumption homes often recover investment faster because electricity savings are higher.

Eastman Residential Solar Solutions

Eastman ensures the installation happens with quality solar products, and these end-to-end solar products are being provided by Eastman. 

For residential installing 1kW, 3kW, or 5kW systems, Eastman manufactures: 

High-Efficiency Solar Panels 

1. ALMM-approved modules

2. Mono PERC & Topcon technology

3. Up to 27-year performance warranty

4. Designed for Indian climate conditions 

Grid-Tie & Hybrid Inverters (3kW–10kW range) 

1. 10-year warranty

2. IP65 protection

3. High efficiency (up to 97%)

4. Compatible with net metering

5. Suitable for 1-phase & 3-phase homes 

Advanced LiFePO4 Lithium Solar Batteries 

1. 6000+ cycle life

2. Intelligent BMS protection

3. Wall-mount, floor-mount & rack options

4. Ideal for hybrid home systems with backup 

Conclusion

Choosing between 1kW vs 3kW vs 5kW solar system depends on: Monthly electricity consumption, Roof space availability, Budget, and Future energy needs.

Quick guideline: 

1. Below 150 units/month → 1kW for small homes & low consumption

2. 250–400 units/month → 3kW for medium families

3. 500+ units/month → 5kW for High-usage homes & future-ready setups 

Selecting the correct system size ensures maximum savings, faster payback, and long-term performance stability. Solar is not one-size-fits-all; proper sizing makes all the difference. 

Contact Eastman for more information.  

Explore Eastman Solar panels Solutions. 

Calculate the Cost of solar solutions for your area. 

Get to know your nearest Store Locator for convenience. 

FAQ’s

Q1. How many units does a 1kW solar system generate? 

A 1kW system generates approximately 120–150 units per month in India. 

Q2. Is a 3kW solar system enough for a 2BHK home? 

Yes. A 3kW system typically supports an average of 2–3 BHK household consumption. 

Q3. How much roof space is required for a 5kW solar system? 

Around 400–500 square feet of shadow-free area are required. 

Q4. Which solar system size gives the best ROI? 

3kW and 5kW systems often provide better ROI due to higher electricity savings. 

Q5. Can I upgrade from 3kW to 5kW later? 

Yes, but system design must allow expansion compatibility. 

Q6. Is subsidy available for 5kW residential solar? 

Yes. Subsidy is available under eligible government schemes for residential rooftop systems. 

Q7. Does Eastman provide residential solar systems? 

Yes. Eastman offers residential solar solutions designed for reliable performance under Indian conditions.

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