Solar Panel Calculator
Calculate solar panel requirements, costs, savings, and environmental benefits
Energy Consumption & Location
Check your electricity bill for yearly consumption. Average US home uses ~11,000 kWh/year
How much of your electricity bill you want to offset with solar
Accounts for shading, dust, temperature losses, and system inefficiencies
Check your electricity bill for current rate. US average is ~15¢/kWh
Panel & Roof Specifications
Exclude shaded areas, chimneys, vents, and areas unsuitable for panels
US average is $3.50/W installed. Includes panels, inverters, installation
Current US federal credit is 30% through 2032
State and local rebates or incentives
Solar System Results
☀️ Recommended System
✅ Your roof has enough space! (100 m² available)
💰 Financial Analysis
Initial Investment
Annual Savings
25-Year Projection
🌍 Environmental Impact
25-Year Environmental Impact
System Configuration
Why Go Solar?
Free fuel source - sunlight costs nothing
Stable energy prices protected from inflation
Increases home value by ~4% on average
Zero emissions during operation
Energy independence and reliability
Installation Tips
Get multiple quotes from certified installers
Check roof condition before installation
South-facing roofs are typically optimal
Consider future energy needs (EVs, etc.)
Research local permits and regulations
Understanding Solar Panel Calculations
System Sizing Formula
Array Size = (Consumption ÷ 365 ÷ Solar Hours) × Offset% ÷ Efficiency%
This formula calculates the minimum solar array size needed to meet your energy goals, accounting for daily solar availability and system losses.
Key Factors:
- • Peak Sun Hours: Hours of equivalent full sunlight
- • Environmental Factor: Real-world efficiency losses
- • Bill Offset: Percentage of electricity to replace
- • Panel Efficiency: How much sunlight converts to electricity
Financial Considerations
Solar panels are a long-term investment. The payback period depends on system cost, local electricity rates, and available incentives.
Cost Factors:
- • Equipment: Panels, inverters, mounting hardware
- • Installation: Labor, permits, electrical work
- • Incentives: Federal/state/local rebates and credits
- • Financing: Cash purchase vs. solar loans/leases
- • Maintenance: Minimal ongoing costs