Calculate Opportunity Cost

Calculate your solar savings, payback period, and 25-year return.

What % of your bill will solar cover?

Net System Cost $0

Year 1 Savings $0

Payback Period 0 Years

25-Year Net Profit $0

Understanding Solar ROI: Is Solar Worth It?

Investing in solar panels is one of the most effective ways to lower your carbon footprint while securing long-term financial stability. However, determining the "Return on Investment" (ROI) involves more than just looking at the sticker price of the panels.

Key Factors in Your Solar ROI Calculation

• The Federal Solar Tax Credit (ITC): As of 2024, the federal government offers a 30% tax credit on the total cost of installation, significantly reducing your net investment.
• Net Metering: This policy allows you to send excess energy back to the grid in exchange for credits on your utility bill, effectively letting your meter "run backward."
• Utility Inflation: While solar costs are fixed once installed, utility rates typically rise by 2% to 5% annually. This makes solar energy more valuable every year.
• Home Value: Studies by Zillow and the LBNL suggest that solar installations can increase property value by an average of 4.1%.

Example ROI Scenario

Let's look at a realistic example for a medium-sized home:

"A homeowner installs an 8kW system for $24,000. After the 30% federal tax credit, the net cost drops to $16,800. If they currently pay $150/month for electricity and the solar system offsets 100% of that, they save $1,800 in the first year. Even without factoring in rising electricity costs, the system pays for itself in about 9.3 years. Over 25 years, accounting for a 3% annual utility hike, the total savings exceed $65,000."

The "Break-Even" Point

The payback period—often called the "break-even" point—is the moment your cumulative electricity savings equal the net cost of the system. For most US homeowners, this occurs between year 6 and year 10. After this point, every kilowatt-hour generated is essentially free energy for the remainder of the system's 25-30 year lifespan.

function calculateSolarROI() { // Get inputs var cost = parseFloat(document.getElementById('systemCost').value); var credit = parseFloat(document.getElementById('taxCredit').value); var monthly = parseFloat(document.getElementById('monthlyBill').value); var offset = parseFloat(document.getElementById('energyOffset').value) / 100; var inflation = parseFloat(document.getElementById('utilityIncrease').value) / 100; // Validation if (isNaN(cost) || isNaN(credit) || isNaN(monthly) || isNaN(offset)) { alert("Please enter valid numerical values."); return; } // Calculations var netCost = cost – credit; var year1Savings = monthly * 12 * offset; // Calculate 25 year savings with inflation var totalSavings = 0; var currentYearSavings = year1Savings; var paybackYear = 0; var cumulativeSavings = 0; var foundPayback = false; for (var i = 1; i = netCost) { // Simple linear interpolation for more accuracy in payback year var previousCumulative = cumulativeSavings – currentYearSavings; var needed = netCost – previousCumulative; paybackYear = (i – 1) + (needed / currentYearSavings); foundPayback = true; } currentYearSavings *= (1 + inflation); } var netProfit = totalSavings – netCost; // Formatting var formatter = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD', maximumFractionDigits: 0 }); // Display results document.getElementById('resNetCost').innerText = formatter.format(netCost); document.getElementById('resYear1').innerText = formatter.format(year1Savings); document.getElementById('resPayback').innerText = foundPayback ? paybackYear.toFixed(1) + " Years" : "25+ Years"; document.getElementById('resTotalROI').innerText = formatter.format(netProfit); document.getElementById('resultsArea').style.display = 'block'; // Scroll to results document.getElementById('resultsArea').scrollIntoView({ behavior: 'smooth', block: 'nearest' }); }