Salary to Hourly Pay Rate Calculator

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Solar Panel ROI & Savings Calculator

US average is roughly 4.0 – 5.5 hours.

Estimated Results

Monthly Production

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Monthly Savings

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Annual Savings

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Payback Period

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Understanding Your Solar Investment and ROI

Switching to solar energy is more than just an environmental choice; it is a significant financial decision. To accurately determine if solar is worth it for your home, you must look beyond the initial installation cost and analyze the 25-year lifetime value of the system.

Key Factors in Solar Calculations

  • Peak Sun Hours: This is not the total daylight time, but the intensity of sunlight that reaches your panels. Areas like Arizona might see 6 hours, while the Pacific Northwest might average 3.5 hours.
  • System Efficiency: Most residential solar systems lose about 15-25% of energy through DC-to-AC conversion (inverters), wiring, and heat. Our calculator applies a standard 0.78 derate factor for realistic estimates.
  • Net Metering: If your utility company offers 1:1 net metering, every kWh you send back to the grid is worth the same as what you buy. This significantly shortens the payback period.

Solar Payback Period Explained

The "Payback Period" is the time it takes for your cumulative energy savings to equal the net cost of the system (after the 30% federal tax credit and local rebates). A typical residential solar payback period in the United States currently ranges from 6 to 10 years.

Example Calculation

Imagine a homeowner in Florida with a 6kW system that cost $12,000 after incentives. If they receive 5 peak sun hours per day:

  • Daily Production: 6kW × 5 hours × 0.78 (efficiency) = 23.4 kWh
  • Monthly Production: 23.4 kWh × 30 days = 702 kWh
  • Monthly Savings: 702 kWh × $0.15/kWh = $105.30
  • Annual Savings: $1,263.60
  • Payback Period: $12,000 / $1,263.6 = 9.5 Years

Over a 25-year lifespan, this system would generate over $31,000 in savings, providing a massive return on the initial $12,000 investment.

function calculateSolarROI() { var monthlyBill = parseFloat(document.getElementById("monthlyBill").value); var electricityRate = parseFloat(document.getElementById("electricityRate").value); var systemSize = parseFloat(document.getElementById("systemSize").value); var totalCost = parseFloat(document.getElementById("totalCost").value); var sunHours = parseFloat(document.getElementById("sunHours").value); // Validate inputs if (isNaN(monthlyBill) || isNaN(electricityRate) || isNaN(systemSize) || isNaN(totalCost) || isNaN(sunHours)) { alert("Please enter valid numerical values for all fields."); return; } // Calculation Logic // Efficiency factor (derate factor for soil, inverter loss, wiring) = 0.78 var efficiency = 0.78; var dailyProduction = systemSize * sunHours * efficiency; var monthlyProduction = dailyProduction * 30.42; // Avg days in month var monthlySavings = monthlyProduction * electricityRate; // Cap savings at the monthly bill (unless net metering allows profit, but conservative is better) if (monthlySavings > monthlyBill) { monthlySavings = monthlyBill; } var annualSavings = monthlySavings * 12; var paybackYears = totalCost / annualSavings; var lifetimeSavings = (annualSavings * 25) – totalCost; // Display Results document.getElementById("resProduction").innerHTML = Math.round(monthlyProduction) + " kWh"; document.getElementById("resMonthlySave").innerHTML = "$" + monthlySavings.toFixed(2); document.getElementById("resAnnualSave").innerHTML = "$" + annualSavings.toFixed(2); document.getElementById("resPayback").innerHTML = paybackYears.toFixed(1) + " Years"; if (lifetimeSavings > 0) { document.getElementById("resLifetime").innerHTML = "Estimated 25-Year Net Profit: $" + Math.round(lifetimeSavings).toLocaleString(); } else { document.getElementById("resLifetime").innerHTML = "System does not pay for itself within 25 years at these rates."; } document.getElementById("solarResult").style.display = "block"; }

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