Calculate your estimated savings and break-even point for home solar installation.
Net System Cost (after tax credit):$0.00
Estimated Payback Period:0 Years
25-Year Total Savings:$0.00
Annual Return on Investment (ROI):0%
How Solar Payback is Calculated
Switching to solar energy is a significant financial decision. To understand when your investment pays for itself, we analyze several key factors:
Gross System Cost: The total upfront price for panels, inverters, and labor.
Federal Investment Tax Credit (ITC): Currently at 30%, this significantly reduces your net cost by providing a dollar-for-dollar credit on your federal taxes.
Utility Inflation: Electricity prices historically rise between 3% and 5% annually. Our calculator accounts for this increasing value of your generated energy.
Example Calculation
Imagine a homeowner installs a system for $20,000. With a 30% Federal Tax Credit, the net cost drops to $14,000. If the system saves $150 per month ($1,800/year), and utility rates rise 4% annually, the payback period is typically between 6 to 8 years. Over a 25-year lifespan, this system could generate over $60,000 in total savings.
Factors That Influence Your ROI
While this calculator provides a robust estimate, your actual results may vary based on:
Sun Exposure: Homes in Arizona will reach payback faster than homes in Maine due to peak sun hours.
Local Incentives: Some states offer SRECs (Solar Renewable Energy Certificates) or local rebates that further reduce costs.
Net Metering: Policies that allow you to sell excess energy back to the grid at retail rates maximize your monthly savings.
function calculateSolarROI() {
var cost = parseFloat(document.getElementById("systemCost").value);
var monthlySavings = parseFloat(document.getElementById("monthlySavings").value);
var taxCreditPercent = parseFloat(document.getElementById("taxCredit").value);
var annualIncrease = parseFloat(document.getElementById("utilityIncrease").value) / 100;
if (isNaN(cost) || isNaN(monthlySavings) || isNaN(taxCreditPercent) || isNaN(annualIncrease)) {
alert("Please enter valid numerical values.");
return;
}
// Step 1: Calculate Net Cost
var taxCreditValue = cost * (taxCreditPercent / 100);
var netCost = cost – taxCreditValue;
// Step 2: Calculate Payback Period with Inflation
var currentBalance = netCost;
var currentAnnualSavings = monthlySavings * 12;
var years = 0;
var totalSavings25 = 0;
// Detailed simulation over 25 years
for (var i = 1; i 0) {
if (currentBalance = 25 ? "25+ Years" : years.toFixed(1) + " Years";
document.getElementById("totalSavingsDisplay").innerText = "$" + totalSavings25.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("roiDisplay").innerText = annualROI.toFixed(2) + "%";
document.getElementById("solar-results").style.display = "block";
}