☀️ Solar Panel Calculator PRO
Estimate system size, energy output, savings, and payback period for solar panel installations.
Dimension Diagram — updates as you type
Roof face with panel layout. Usable area after pitch and shading decides the panel count.
1 Roof Dimensions
Angle affects usable area via cos(angle). 0° = flat, 45° = steep.
2 Panel Specifications
3 Environment & Cost
Average peak sun hours. 4-5 hrs typical, 6-7 in desert climates.
Results
Roof Analysis
System Specifications
Energy Output
Savings & ROI
Cost Breakdown
⚠️ Pre-Export Checklist
- Roof dimensions verified on-site
- Roof structural capacity confirmed for panel weight
- Shading from trees/neighboring buildings assessed
- Local solar permits and HOA requirements checked
- Utility net metering policy confirmed
- Electrical panel capacity verified
- Panel and inverter warranty terms reviewed
Professional Solar Estimation Guide
📐 Formulas & Calculations ▼
Usable Roof Area
UsableArea = Length × Width × cos(angle) × 0.85 (shading factor)
The shading factor accounts for obstructions, setbacks, and orientation losses. Adjust your roof angle to see the impact on usable area.
Panel Count
Panels = UsableArea ÷ PanelArea
Each panel is roughly 17-18 sq ft. A typical 5kW system needs 12-15 panels.
Annual Output
Annual = SystemSize(kW) × SunHours × 365
Output varies by location. 4 sun hours/day is average US, 6+ in Southwest.
Payback Period
Payback = TotalCost ÷ AnnualSavings
Most residential systems pay back in 6-12 years with 25-30 year panel life.
💡 Pro Tips ▼
- South-facing roofs produce 15-25% more energy than east/west in the Northern Hemisphere.
- Micro-inverters are better for partially shaded roofs; string inverters for unshaded arrays.
- Battery storage adds 30-50% to system cost but provides backup power during outages.
- Federal tax credits can offset 30% of total cost — check current incentives in your area.
- Net metering policies vary by utility — confirm buyback rates before calculating savings.
Solar Installation — 3D Preview
Drag to rotate — Scroll to zoom
Verwandte Rechner
Frequently used together on the same project.
Client & Quote (prints on PDF & Excel)
Adjustments (applies to exports)
Contingency is added as a separate line on the exported cost summary. Waste % is printed as an advisory reminder.
Project notes (prints on PDF & Excel)
Result compare (A/B)
| Item | Pinned | Current | Change |
|---|---|---|---|
Saved rates auto-apply from your Price Library. Advanced details stay in your browser — nothing is uploaded except inside your own PDF/Excel exports.
📖 So Verwenden Sie den Solarrechner
Geben Sie Ihren durchschnittlichen monatlichen Stromverbrauch ein.
Wählen Sie Ihren Standort oder Spitzenstunden.
Wählen Sie die Panel-Wattzahl.
Geben Sie Kosten pro Watt ein.
Klicken Sie auf Berechnen.
Überprüfen Sie die Details.
📐 Solarformeln
⚠️ Häufige Berechnungsfehler
Zukünftige Preiserhöhungen nicht berücksichtigen.
Verschattung ignorieren.
Zustand und Ausrichtung des Dachs übersehen.
Wechselrichterverluste ausschließen.
Nicht alle Kosten einbeziehen.
💡 Professionelle Tipps
Lassen Sie eine professionelle Standortbewertung erstellen.
Batteriespeicher in Betracht ziehen.
Mehrere Angebote einholen.
Verfügbare Anreize prüfen.
Dachzustand sicherstellen.
Ausrichtung und Neigung beachten.
Leistung regelmäßig überwachen.
❓ Häufige Fragen
Hängt vom Verbrauch ab. Ein typisches Haus benötigt 20 bis 25 Panels.
Durchschnittliche Kosten betragen 2,50 bis 3,50 Dollar pro Watt. Ein 6kW-System kostet 15.000 bis 21.000 Dollar vor Anreizen.
Die meisten haben 25 bis 30 Jahre Garantie.
Ja, sie erzeugen Strom mit reduzierter Effizienz, typischerweise 10 bis 25 Prozent.
Minimale Wartung: gelegentliche Reinigung und jährliche Inspektionen.
🏗️ Praktische Installationsbeispiele
Verwenden Sie unseren Rechner zur Bestimmung der Systemgröße und Kosten für Ihre Solarinstallation.
✅Method, Sources & Review
Maintained by theBuildingCalc methods desk· Last reviewedSeptember 23, 2026. This calculator implements the standards and references below; every figure can be rechecked against the formulas and worked example on this page.
Results are estimates, not engineering advice. Verify against local codes and licensed professionals for structural, electrical, and gas work. See ourTerms. Spotted an error? Report it— corrections ship with the next review.