Solar System Size Calculator: Find the Perfect Capacity for Your Home

How to Size Your Solar System

Choosing the right solar system size is crucial. Too small won't cover your needs; too large wastes money. Here's how to calculate perfectly.

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Quick Formula

Solar Capacity (kW) = Monthly Consumption (units) ÷ 120

Example: 360 units/month ÷ 120 = 3 kW system

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Step-by-Step Calculation

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Step 1: Check Your Electricity Bill

Look at your last 12 months of bills and note:
- Monthly consumption (units/kWh)
- Calculate average monthly consumption
- Note peak summer consumption

Vadodara Average:
- 1 BHK: 150-200 units
- 2 BHK: 250-350 units
- 3 BHK: 350-500 units
- 4 BHK+: 500-800 units
- Bungalow: 800-1500 units

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Step 2: Consider Future Needs

Plan for next 5-10 years:
- Planning to buy AC? Add 100-150 units
- Electric vehicle? Add 200-300 units
- Family expansion? Add 20-30%

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Step 3: Check Roof Space

Space Required per kW:
- Mono PERC panels: 60-70 sq ft
- Polycrystalline: 80-90 sq ft
- Bifacial: 55-65 sq ft

Vadodara Roof Types:
- RCC flat roof: Best for solar
- Sloped tile roof: Needs special mounting
- Metal sheet roof: Requires reinforcement

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Step 4: Account for Efficiency

Vadodara solar generation:
- 1 kW generates ~120-140 units/month
- Summer: 140-150 units/kW
- Winter: 100-120 units/kW
- Monsoon: 80-100 units/kW

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Solar Size Recommendation Chart

| Monthly Bill | Units Consumed | Recommended Size |
|-------------|----------------|------------------|
| ₹500-1,000 | 100-150 | 1 kW |
| ₹1,000-1,500 | 150-250 | 2 kW |
| ₹1,500-2,500 | 250-350 | 3 kW |
| ₹2,500-3,500 | 350-500 | 4 kW |
| ₹3,500-5,000 | 500-700 | 5-6 kW |
| ₹5,000-8,000 | 700-1000 | 7-8 kW |
| ₹8,000+ | 1000+ | 10 kW+ |

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Subsidy Consideration

PM Surya Ghar Subsidy Structure:
- Up to 2 kW: ₹30,000/kW
- 2-3 kW: Additional ₹18,000/kW
- Above 3 kW: No additional subsidy

Optimal Residential Size: 3 kW
- Maximum subsidy benefit (₹78,000)
- Covers most household needs
- Excellent ROI

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Sample Calculations

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Case 1: 2 BHK Apartment

- Monthly bill: ₹2,000
- Consumption: 300 units
- Recommended: 3 kW system
- Generation: 360-400 units
- Result: Zero bill + surplus credits

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Case 2: 3 BHK Villa

- Monthly bill: ₹4,000
- Consumption: 550 units
- Recommended: 5 kW system
- Generation: 600-700 units
- Result: Zero bill + export income

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Case 3: Large Bungalow

- Monthly bill: ₹8,000
- Consumption: 1100 units
- Recommended: 10 kW system
- Generation: 1200-1400 units
- Result: Complete energy independence

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Free Site Survey

Not sure about your requirements? We offer FREE site surveys in Vadodara:
- Roof assessment
- Shadow analysis
- Custom system design
- Exact cost estimate

📞 Book your free survey: +91-6353583148