Calculate your potential savings and break-even point
Results Summary
Net System Cost
$0
Payback Period
0 Years
25-Year Total Savings
$0
Estimated ROI
0%
Understanding Solar Panel ROI
Investing in solar energy is not just an environmental choice; it is a financial one. To determine if solar is right for your home, you must understand the Solar Payback Period—the time it takes for the energy savings to equal the initial cost of installation.
Key Factors in Your Calculation
Gross System Cost: The total price before any incentives. This includes panels, inverters, racking, and labor.
Federal Investment Tax Credit (ITC): Currently, the US federal government offers a 30% credit on the total cost of your solar system through 2032.
Solar Offset: This is the percentage of your total energy consumption that your solar panels cover. A 100% offset means you produce as much energy as you use.
Utility Inflation: Traditionally, electricity prices rise by 2% to 5% per year. Solar protects you from these future hikes.
Example Calculation
If you purchase a $20,000 system:
30% Federal Credit saves you $6,000.
A $1,000 local rebate reduces the cost further.
Your Net Cost is $13,000.
If your monthly bill is $150 and solar covers 100%, you save $1,800 in Year 1.
Without accounting for rate increases, your payback would be ~7.2 years.
Most modern solar panels are warrantied for 25 years. This means after your payback period is complete, you will enjoy 15-20 years of "free" electricity, leading to massive long-term savings.
function calculateSolarROI() {
// Get Input Values
var systemCost = parseFloat(document.getElementById('systemCost').value);
var taxCreditPercent = parseFloat(document.getElementById('taxCredit').value);
var rebates = parseFloat(document.getElementById('rebates').value);
var monthlyBill = parseFloat(document.getElementById('monthlyBill').value);
var solarOffset = parseFloat(document.getElementById('solarOffset').value) / 100;
var utilityHike = parseFloat(document.getElementById('utilityHike').value) / 100;
// Validate
if (isNaN(systemCost) || isNaN(monthlyBill)) {
alert("Please enter valid numbers for system cost and monthly bill.");
return;
}
// Calculations
var taxCreditAmount = systemCost * (taxCreditPercent / 100);
var netCost = systemCost – taxCreditAmount – rebates;
if (netCost < 0) netCost = 0;
var initialAnnualSavings = monthlyBill * 12 * solarOffset;
// Payback Period Calculation with Inflation
var cumulativeSavings = 0;
var years = 0;
var maxYears = 50; // Safety break
var annualSavingCurrent = initialAnnualSavings;
while (cumulativeSavings < netCost && years < maxYears) {
years++;
cumulativeSavings += annualSavingCurrent;
annualSavingCurrent *= (1 + utilityHike);
}
// 25 Year Total Savings
var totalSavings25 = 0;
var tempAnnualSaving = initialAnnualSavings;
for (var i = 1; i = maxYears) {
document.getElementById('resPayback').innerText = '50+ Years';
} else {
document.getElementById('resPayback').innerText = years + ' Years';
}
document.getElementById('resTotalSavings').innerText = '$' + totalSavings25.toLocaleString(undefined, {minimumFractionDigits: 0, maximumFractionDigits: 0});
document.getElementById('resROI').innerText = roiTotal.toFixed(1) + '%';
// Scroll to results on mobile
document.getElementById('results-area').scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}
#solar-calculator-wrapper input:focus {
outline: none;
border-color: #27ae60 !important;
box-shadow: 0 0 5px rgba(39, 174, 96, 0.2);
}
@media (max-width: 600px) {
#solar-calculator-wrapper .input-group {
grid-column: span 2;
}
}