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Solar Panel Savings & ROI Calculator

Your Solar Estimates

Recommended System Size: kW

Estimated Total Cost:

Estimated Yearly Savings:

Payback Period: Years

*Estimation accounts for 30% Federal Tax Credit.

function calculateSolar() { var bill = parseFloat(document.getElementById('monthlyBill').value); var sun = parseFloat(document.getElementById('sunHours').value); var rate = parseFloat(document.getElementById('elecRate').value); var cpw = parseFloat(document.getElementById('costPerWatt').value); if (bill > 0 && sun > 0 && rate > 0 && cpw > 0) { // Calculation Logic var monthlyKWh = bill / rate; var dailyKWh = monthlyKWh / 30; var systemSizeKW = dailyKWh / sun; // Adjust for standard efficiency losses (approx 20%) var recommendedSize = systemSizeKW * 1.2; var grossCost = recommendedSize * 1000 * cpw; var netCost = grossCost * 0.70; // 30% Tax Credit var yearlySavings = bill * 12; var payback = netCost / yearlySavings; document.getElementById('systemSizeDisplay').innerText = recommendedSize.toFixed(2); document.getElementById('totalCostDisplay').innerText = '$' + netCost.toLocaleString(undefined, {minimumFractionDigits: 0, maximumFractionDigits: 0}); document.getElementById('yearlySavingsDisplay').innerText = '$' + yearlySavings.toLocaleString(undefined, {minimumFractionDigits: 0, maximumFractionDigits: 0}); document.getElementById('paybackDisplay').innerText = payback.toFixed(1); document.getElementById('solar-results').style.display = 'block'; } else { alert('Please enter valid positive numbers in all fields.'); } }

How to Use the Solar Panel Savings Calculator

Switching to solar energy is one of the most effective ways to reduce your carbon footprint while drastically cutting your monthly utility expenses. This calculator helps you estimate the system size you need, the total investment required, and how long it will take for the system to pay for itself through energy savings.

Understanding the Key Metrics

  • Monthly Electricity Bill: Your average monthly payment to your utility provider. High bills typically indicate a faster ROI for solar.
  • Peak Sun Hours: This isn't just daylight; it's the intensity of sunlight. Areas like Arizona might see 6+ hours, while the Pacific Northwest may average 3.5 to 4 hours.
  • Electricity Rate ($/kWh): Look at your utility bill for the "Price per kWh." The higher this rate, the more money you save by generating your own power.
  • Install Cost ($/Watt): The current national average in the US is roughly $2.50 to $3.50 per watt, including parts and labor.

How We Calculate Your Solar ROI

Our formula determines your energy needs based on your monthly bill and local sunlight availability. We then apply the 30% Federal Investment Tax Credit (ITC) to your total installation cost. This credit is a dollar-for-dollar reduction in the income tax that a person or company would otherwise pay the federal government.

Example Calculation

If you live in a region with 5 sun hours per day and pay $150 per month for electricity at a rate of $0.16/kWh, your home consumes about 937 kWh per month. To cover this 100%, you would need approximately a 7.5 kW system. At $3.00/watt, the gross cost is $22,500. After the 30% tax credit, your net investment is $15,750. With yearly savings of $1,800, your system pays for itself in just 8.7 years.

Factors That Influence Your Results

While this calculator provides a highly accurate estimate, several local factors can change the final numbers:

  • Roof Orientation: South-facing roofs generate the most power in the Northern Hemisphere.
  • Local Incentives: Many states offer additional rebates or SRECs (Solar Renewable Energy Credits) that can shorten your payback period.
  • Net Metering: Some utilities buy back your excess energy at retail rates, while others offer lower wholesale rates.
  • Shading: Nearby trees or buildings can reduce efficiency and require a larger system size.

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