Solar Panel Calculator

Calculate solar panel system size based on your electric bill and location. Compare panel types, estimate installation cost after federal tax credit, project 25-year savings with degradation, and determine payback period.

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System Size
9.2 kW
23 panels
Net Cost
$23,646
after 30% tax credit
Payback
10
years
25-Yr Profit
$53,880
net savings
Cost Breakdown
ItemCost
Monocrystalline Panels (23 x 400W)$25,760
Inverter(s)$2,760
Roof-Mounted Mounting$2,760
Electrical Work$2,000
Permits & Inspections$500
Gross Cost$33,780
Federal Tax Credit (30%)-$10,134
Net Cost$23,646
Production & Savings (25-Year Projection)
Year 1 Production
14,775 kWh
saves $2,216/yr
25-Year Savings
$77,526
356 MWh produced
CO2 Offset
142.4 tons
over 25 years
Panel Type Comparison
PanelWatts$/WEfficiencyNotes
MonocrystallineSelected400W$2.822%Highest efficiency, premium look, best for limited space
Polycrystalline340W$2.417%Good value, slightly lower efficiency, blue tint
Thin-Film250W$212%Most affordable, flexible, requires more space

How to Use Solar Panel Calculator

  1. 1Enter your monthly electric bill
  2. 2Select sun region and panel type
  3. 3Review system size and cost
  4. 4See payback period and 25-year savings

Frequently Asked Questions

How many solar panels do I need?

Divide your annual kWh usage by your area's peak sun hours × 365 × panel wattage. A home using 10,000 kWh/year in an area with 5 peak sun hours needs roughly 5.5kW, or about 14 panels at 400W each.

How much do solar panels cost?

Average cost is $2.50-3.50 per watt before incentives. A typical 8kW system costs $20,000-28,000. After the 30% federal ITC tax credit, net cost drops to $14,000-19,600. Many states offer additional rebates.

What is the payback period for solar?

Typically 6-12 years depending on electricity rates, sun exposure, and incentives. In high-rate states like California, payback can be 5-7 years. After payback, solar provides free electricity for the remaining 15-20 years of panel life.

About Solar Panel Calculator

Calculate solar panel system size based on your electric bill and location. Compare panel types, estimate installation cost after federal tax credit, project 25-year savings with degradation, and determine payback period.

NexTool's Solar Panel Calculator is completely free to use with no sign-up required. Your data is processed directly in your browser and never sent to our servers, ensuring complete privacy and instant results.

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