How many solar panels do I need to run a 1.5 ton AC?

A 5-star 1.5 ton inverter AC running 8 hours/day consumes approximately 9–11 kWh/day. You need a 1.5–2 kW solar system (5–7 panels of 400W each) to fully offset it. A 3-star AC needs slightly more — around 2–2.5 kW.

What is the cost of a 3kW solar system in India in 2026?

A 3kW rooftop solar system costs ₹1,80,000–₹2,10,000 before subsidy at ₹60,000–₹70,000/kW in 2026. After PM Surya Ghar central subsidy of ₹78,000, the net cost is approximately ₹1,00,000–₹1,30,000.

How much roof area does a 3kW solar system need?

A 3kW solar system using 400W panels (8 panels) requires approximately 280–320 sq.ft (26–30 sq.m) of shadow-free roof area. This includes spacing between panels for ventilation.

What is the standard roof area required per solar panel in India?

A 400W monocrystalline panel measures roughly 2.0 sq m (21.5 sq ft). With panel gaps, walkways, and shadow clearance, count on 2.3–2.5 sq m per panel in practice. A 6-panel system needs about 120–130 sq ft of unshaded roof.

Can I run 2 ACs on the same solar system?

Absolutely — solar systems are sized based on total daily load, not the number of units. Just add both ACs in the calculator with their daily usage hours. If both run simultaneously, the system will need to handle the combined peak load, which the calculator accounts for.

What is the cost of a 3 kW solar system in India in 2026?

As of 2026, a grid-tied 3 kW solar system (panels + inverter + mounting + installation) costs approximately ₹1.3L–₹1.8L. After PM Surya Ghar central subsidy of ₹78,000, your net cost can drop to ₹55,000–₹1L depending on state and vendor.

Should I go on-grid or off-grid for running ACs?

On-grid (net metering) is the right choice for running ACs in India. It is cheaper (no batteries), earns you bill credits for surplus generation, and qualifies for PM Surya Ghar subsidy. Off-grid with batteries is only justified for remote areas without reliable grid power.

Does the calculator account for inverter losses?

Yes. The calculator uses an 80% system efficiency factor (industry standard for string inverters in India). This accounts for inverter losses, wiring losses, soiling, and temperature derating — giving you a realistic, slightly conservative system size.

How accurate is the roof area estimate?

The roof area calculation uses the standard panel dimension for your selected wattage plus a 15% margin for inter-panel spacing, walkways, and installation clearance. Actual usable roof area may vary based on roof shape, shading, and obstructions — always verify with an installer's site survey.

What panel wattage should I choose for running ACs?

400W monocrystalline PERC panels are the sweet spot for Indian homes — good efficiency (20–22%), widely available, competitive pricing (~₹18–22/W in 2026), and manageable size. If roof space is limited, go for 450W or 545W panels to fit the same system in fewer panels.

LIVE: 2026 Installation Costs Updated

Solar System Sizing — Multi-AC India 2026

Solar Panel Size Calculator (2026)

Add all your air conditioners, set daily usage hours, and instantly get — exact system kW required, panel count, roof area needed, and estimated installation cost for your home in India.

Multi-AC Sizing

All ACs in One Go

City-Wise Irradiance

28 States · Real Data

₹45K/kW Avg Cost

2026 Market Rates

Roof Area Calc

sq.ft Required

Size My Solar System Check Subsidy (₹78K)

A 1.5 ton 5-star AC running 8 hrs/day needs approximately 1.2 kW of solar panels to fully offset its consumption in most Indian states.

Add All Your ACs

Enter every AC in your home — bedroom, hall, office — and get sizing for your full load, not just one unit. Supports up to 6 ACs simultaneously.

Roof Area Check

Instantly see how many square feet of roof space your solar array will need. Helps you confirm fit before calling an installer.

Full Cost Estimate

Get a realistic installation cost estimate based on 2026 India market rates — including panels, inverter, mounting, and wiring — before you talk to a vendor.

Solar Panel Size Calculator

Add all your ACs → get exact system size, panel count & roof area

Step 1 — Your Air Conditioners

AC Unit 1

No. of Units

Tonnage

Star Rating

Daily Hours

Step 2 — System Configuration

Panel Wattage

Your Sun Zone

Electricity Rate (₹/unit)

₹7

Average India: ₹6–9/unit. Check your bill.

Quick Summary

AC units added:1

Total daily load:10.0 kWh

Step 3 — See system kW, panel count, roof area & cost estimate

Quick Reference — Solar Size Guide for Common AC Setups

Based on 5.5 peak sun hours (average India), 400W panels, 80% system efficiency

AC Setup	Star Rating	Daily Load	System Size	No. of Panels	Roof Area	Est. Cost (Before Subsidy)
0.75T	5★	4.2 kWh	1 kW	3 panels	~65 sq ft	₹50K
1T	5★	5.4 kWh	1.25 kW	4 panels	~85 sq ft	₹65K
1.5T	5★	7.8 kWh	1.8 kW	5 panels	~105 sq ft	₹92K
1.5T	3★	10 kWh	2.3 kW	6 panels	~130 sq ft	₹1.15L
2T	5★	10.4 kWh	2.4 kW	6 panels	~130 sq ft	₹1.2L
2T	3★	13.2 kWh	3 kW	8 panels	~170 sq ft	₹1.5L
2×1.5T	3★	20 kWh	4.6 kW	12 panels	~260 sq ft	₹2.3L
3×1.5T	3★	30 kWh	6.8 kW	17 panels	~370 sq ft	₹3.4L

PM Surya Ghar subsidy can reduce these costs by up to ₹78,000. Calculate your subsidy →

How the Solar Sizing Formula Works

Solar panel sizing for ACs follows a simple but precise formula. The key is calculating your total daily energy load in kWh — the sum of all AC units running their daily hours.

From there, the system size in kW = daily load ÷ (peak sun hours × inverter efficiency). India's average is 5.5 peak sun hours, and modern string inverters run at ~80% efficiency.

Panel count = system kW ÷ panel wattage. Roof area adds 15% margin over the actual panel dimensions for gaps and clearance. Installed cost runs ₹45,000–₹55,000 per kW in 2026 (all-inclusive).

The Formula

Daily Load (kWh)

Σ (AC Watts × Hours × Count) ÷ 1000

System Size (kW)

Daily Load ÷ (Sun Hours × 0.80)

Panel Count

⌈System kW × 1000 ÷ Panel Wattage⌉

Roof Area (sqft)

Panels × Panel Area × 1.15 × 10.76

Install Cost

System kW × ₹50,000

Solar Panel Sizing — FAQ

Everything you need to know before buying solar for your ACs

A 1.5 ton 3-star inverter AC uses about 1,250W. Running 8 hours = 10 kWh/day. With 5.5 peak sun hours and 80% inverter efficiency, you need roughly a 2.3 kW system — about 6 panels of 400W each. Roof area needed: ~120 sq ft.