Moving Van Cost Calculator

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Solar Panel Savings Calculator

Calculate your potential energy savings and investment payback period.

Estimated Monthly Savings $0.00
Payback Period (Years) 0.0
Net System Cost $0.00
25-Year Lifetime Savings $0.00

How to Use the Solar Panel Savings Calculator

Deciding to go solar is a significant financial decision. This tool helps you estimate the return on investment (ROI) by looking at your current energy costs, local sunlight availability, and system size. By entering your specific details, you can see how long it will take for the energy savings to pay for the system itself.

Key Metrics Explained

  • System Size: Most residential systems range from 5kW to 10kW. A larger system generates more power but has a higher upfront cost.
  • Daily Sunlight Hours: This isn't just "daylight," but peak sun hours where the sun is at the right angle to produce maximum energy. The US average is roughly 4 to 5.5 hours.
  • Incentives: The Federal Investment Tax Credit (ITC) currently allows you to deduct a significant percentage of your solar installation costs from your federal taxes.

Real-World Example Calculation

If you live in a sunny state like Arizona and install a 6kW system for $18,000:

  1. Federal Tax Credit: At 30%, you save $5,400 immediately, bringing your net cost to $12,600.
  2. Energy Production: A 6kW system with 5 peak hours daily produces roughly 900 kWh per month (accounting for typical 15-20% system losses).
  3. Savings: If your rate is $0.15/kWh, you save $135 per month.
  4. Payback: $12,600 net cost divided by ($135 x 12 months) results in a payback period of approximately 7.7 years.

Factors That Improve Your ROI

Several external factors can speed up your solar payback period. Net Metering is the most critical: it allows you to send excess energy back to the grid for a credit on your bill. Additionally, as utility rates increase (historically 2-3% annually), your solar savings actually grow over time because you are "locking in" your electricity price.

function calculateSolarSavings() { var bill = parseFloat(document.getElementById('solar_monthly_bill').value); var rate = parseFloat(document.getElementById('solar_rate').value); var size = parseFloat(document.getElementById('solar_size').value); var cost = parseFloat(document.getElementById('solar_cost').value); var taxCredit = parseFloat(document.getElementById('solar_incentive').value); var hours = parseFloat(document.getElementById('solar_hours').value); if (isNaN(bill) || isNaN(rate) || isNaN(size) || isNaN(cost) || isNaN(hours)) { alert("Please enter valid numbers in all fields."); return; } // Calculation Logic // Daily Production = Size (kW) * Hours * Efficiency (standard derate factor of 0.77) var dailyProduction = size * hours * 0.77; var monthlyProduction = dailyProduction * 30.42; // Avg days in month // Monthly Savings (cannot exceed current bill unless net metering allows profit, // but for simple savings we cap it at the bill amount for realism) var calculatedMonthlySavings = monthlyProduction * rate; var actualMonthlySavings = Math.min(bill, calculatedMonthlySavings); // Financials var netCost = cost * (1 – (taxCredit / 100)); var annualSavings = actualMonthlySavings * 12; var paybackPeriod = netCost / annualSavings; // Lifetime Savings (25 year standard warranty life) // Accounting for slight panel degradation (~0.5% per year) var lifetimeTotal = 0; var yearlySavings = annualSavings; for(var i = 0; i < 25; i++) { lifetimeTotal += yearlySavings; yearlySavings = yearlySavings * 0.995; // 0.5% degradation } var netLifetimeSavings = lifetimeTotal – netCost; // Display Results document.getElementById('res_monthly').innerText = '$' + actualMonthlySavings.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); document.getElementById('res_payback').innerText = paybackPeriod.toFixed(1) + ' Years'; document.getElementById('res_net_cost').innerText = '$' + netCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); document.getElementById('res_lifetime').innerText = '$' + netLifetimeSavings.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); document.getElementById('solar_results').style.display = 'block'; document.getElementById('solar_results').scrollIntoView({ behavior: 'smooth', block: 'nearest' }); }

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