Solar Panel Price Calculator

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Solar Panel Price Calculator

Estimate the cost and potential savings of installing a solar panel system for your home. This calculator helps you understand the factors influencing solar system pricing and your potential return on investment.

Your typical electricity consumption from your utility bill.
Average hours of direct sunlight your location receives per day. (e.g., 4-5 for many US regions)
Typical cost to install solar per watt in your area. (National average ~ $2.50 – $3.50)
The rate you pay for electricity from your utility company.
The current federal tax credit for solar installations.
Any specific state or local rebates you might qualify for.
Accounts for inefficiencies (inverter, wiring, temperature, etc.).
Average annual increase in electricity prices.
How much panel efficiency typically decreases per year.
function calculateSolarPrice() { var monthlyKWH = parseFloat(document.getElementById("monthlyKWH").value); var peakSunHours = parseFloat(document.getElementById("peakSunHours").value); var costPerWatt = parseFloat(document.getElementById("costPerWatt").value); var electricityPrice = parseFloat(document.getElementById("electricityPrice").value); var federalTaxCredit = parseFloat(document.getElementById("federalTaxCredit").value) / 100; var stateRebate = parseFloat(document.getElementById("stateRebate").value); var systemLossFactor = parseFloat(document.getElementById("systemLossFactor").value) / 100; var electricityInflation = parseFloat(document.getElementById("electricityInflation").value) / 100; var panelDegradation = parseFloat(document.getElementById("panelDegradation").value) / 100; // Input validation if (isNaN(monthlyKWH) || monthlyKWH <= 0 || isNaN(peakSunHours) || peakSunHours <= 0 || isNaN(costPerWatt) || costPerWatt <= 0 || isNaN(electricityPrice) || electricityPrice <= 0 || isNaN(federalTaxCredit) || federalTaxCredit 1 || isNaN(stateRebate) || stateRebate < 0 || isNaN(systemLossFactor) || systemLossFactor = 1 || isNaN(electricityInflation) || electricityInflation < 0 || isNaN(panelDegradation) || panelDegradation < 0) { document.getElementById("solarResults").innerHTML = "Please enter valid positive numbers for all fields."; return; } // 1. Calculate Annual Energy Needed var annualKWHNeeded = monthlyKWH * 12; // 2. Calculate Daily Energy Needed var dailyKWHNeeded = annualKWHNeeded / 365; // 3. Calculate System Size (kW) // Formula: (Daily KWH Needed / Peak Sun Hours) / (1 – System Loss Factor) var estimatedSystemSizeKW = (dailyKWHNeeded / peakSunHours) / (1 – systemLossFactor); var estimatedSystemSizeWatts = estimatedSystemSizeKW * 1000; // 4. Calculate Total System Cost var totalSystemCost = estimatedSystemSizeWatts * costPerWatt; // 5. Calculate Cost After Federal Tax Credit var costAfterFederalCredit = totalSystemCost * (1 – federalTaxCredit); // 6. Calculate Cost After All Incentives var costAfterIncentives = costAfterFederalCredit – stateRebate; if (costAfterIncentives < 0) costAfterIncentives = 0; // Cannot have negative cost // 7. Calculate Annual Savings (Year 1) var annualSavingsYear1 = annualKWHNeeded * electricityPrice; // 8. Estimate Payback Period (considering inflation and degradation) var cumulativeSavings = 0; var years = 0; var currentAnnualSavings = annualSavingsYear1; var effectiveCost = costAfterIncentives; // Cap at 50 years to prevent infinite loops for very high costs or low savings while (cumulativeSavings < effectiveCost && years < 50) { years++; cumulativeSavings += currentAnnualSavings; // Adjust savings for next year: increase due to electricity inflation, decrease due to panel degradation currentAnnualSavings = currentAnnualSavings * (1 + electricityInflation) * (1 – panelDegradation); } var estimatedPayback = years; if (cumulativeSavings < effectiveCost) { // If 50 years passed and still not paid back estimatedPayback = "More than 50"; } // Display Results var resultsHTML = "

Your Solar System Estimate:

"; resultsHTML += "Estimated System Size: " + estimatedSystemSizeKW.toFixed(2) + " kW"; resultsHTML += "Estimated Total System Cost (Before Incentives): $" + totalSystemCost.toFixed(2) + ""; resultsHTML += "Cost After Federal Tax Credit: $" + costAfterFederalCredit.toFixed(2) + ""; resultsHTML += "Estimated Cost After All Incentives: $" + costAfterIncentives.toFixed(2) + ""; resultsHTML += "Estimated Annual Savings (Year 1): $" + annualSavingsYear1.toFixed(2) + ""; resultsHTML += "Estimated Payback Period: " + estimatedPayback + " years"; document.getElementById("solarResults").innerHTML = resultsHTML; } .solar-panel-calculator-wrapper { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background: #f9f9f9; padding: 25px; border-radius: 10px; box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08); max-width: 700px; margin: 30px auto; border: 1px solid #eee; } .solar-panel-calculator-wrapper h2 { text-align: center; color: #2c3e50; margin-bottom: 20px; font-size: 1.8em; } .solar-panel-calculator-wrapper p { color: #555; line-height: 1.6; margin-bottom: 15px; } .calculator-form .form-group { margin-bottom: 18px; } .calculator-form label { display: block; margin-bottom: 8px; font-weight: bold; color: #34495e; font-size: 0.95em; } .calculator-form input[type="number"] { width: calc(100% – 22px); padding: 12px; border: 1px solid #ccc; border-radius: 6px; font-size: 1em; box-sizing: border-box; transition: border-color 0.3s ease; } .calculator-form input[type="number"]:focus { border-color: #28a745; outline: none; box-shadow: 0 0 5px rgba(40, 167, 69, 0.3); } .calculator-form small { display: block; color: #777; margin-top: 5px; font-size: 0.85em; } .calculator-form button { display: block; width: 100%; padding: 14px 20px; background-color: #28a745; color: white; border: none; border-radius: 6px; font-size: 1.1em; font-weight: bold; cursor: pointer; transition: background-color 0.3s ease, transform 0.2s ease; margin-top: 25px; } .calculator-form button:hover { background-color: #218838; transform: translateY(-2px); } .calculator-results { margin-top: 30px; padding: 20px; background-color: #e6f7ed; border: 1px solid #c3e6cb; border-radius: 8px; color: #155724; } .calculator-results h3 { color: #155724; margin-top: 0; margin-bottom: 15px; font-size: 1.5em; text-align: center; } .calculator-results p { margin-bottom: 10px; font-size: 1.05em; line-height: 1.5; } .calculator-results p strong { color: #0a3d15; }

Understanding Solar Panel Pricing

Going solar is a significant investment that can lead to substantial long-term savings and environmental benefits. The cost of a solar panel system isn't fixed; it depends on several key factors, including your energy consumption, location, system size, and available incentives.

Key Factors Influencing Solar Costs:

  • Energy Consumption (kWh/month): This is the most crucial factor. The more electricity you use, the larger the solar system you'll need to offset your usage, and thus, the higher the initial cost. Your utility bills provide this information.
  • Average Daily Peak Sun Hours: The amount of effective sunlight your location receives directly impacts how efficiently your panels can generate electricity. Sunnier regions require smaller systems to produce the same amount of power compared to less sunny areas.
  • Average Installed Cost per Watt ($/Watt): This is the industry benchmark for solar pricing. It includes the cost of panels, inverters, mounting hardware, labor, permits, and other installation expenses. This rate varies by region, installer, and equipment quality.
  • Current Electricity Price ($/kWh): Your current electricity rate determines how much you save by generating your own power. Higher electricity prices mean greater savings and a faster payback period for your solar investment.
  • Federal Solar Tax Credit: The Investment Tax Credit (ITC) is a significant federal incentive that allows homeowners to deduct a percentage of the cost of installing a solar energy system from their federal taxes. This dramatically reduces the net cost of solar.
  • State/Local Rebates and Incentives: Many states, counties, and even utility companies offer additional rebates, tax credits, or performance-based incentives (like SRECs) that can further lower your out-of-pocket expenses.
  • System Loss Factor: No solar system is 100% efficient. Factors like inverter efficiency, wiring losses, temperature, dust, and shading can reduce the actual power output. A typical loss factor ranges from 15-25%.
  • Annual Electricity Price Inflation: Electricity prices tend to rise over time. Accounting for this inflation helps provide a more realistic estimate of your long-term savings and payback period, as the value of the electricity you generate increases each year.
  • Annual Panel Degradation Rate: Solar panels are highly durable, but their efficiency slightly decreases over time. Most quality panels degrade by about 0.5% per year, meaning they'll still be producing over 80% of their original output after 25 years.

How the Calculator Works:

Our calculator first determines the necessary system size (in kilowatts) based on your energy consumption and local sunlight. It then estimates the total cost, applies federal and state incentives, and projects your first-year savings. Finally, it provides an estimated payback period, considering the annual increase in electricity prices and the slight degradation of panel efficiency over time, giving you a comprehensive financial outlook for your solar investment.

Remember, this calculator provides an estimate. For an accurate quote, it's always best to consult with local solar installers who can assess your specific property and energy needs.

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