.ppa-calc-header { background: #1a5f7a; color: #ffffff; padding: 30px 20px; text-align: center; }
.ppa-calc-header h1 { margin: 0; font-size: 28px; font-weight: 700; }
.ppa-calc-header p { margin: 10px 0 0; opacity: 0.9; }
.ppa-calc-body { padding: 30px; }
.ppa-calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 25px; }
@media (max-width: 600px) { .ppa-calc-grid { grid-template-columns: 1fr; } }
.ppa-input-group { margin-bottom: 15px; }
.ppa-input-group label { display: block; font-weight: 600; margin-bottom: 8px; font-size: 14px; }
.ppa-input-group input { width: 100%; padding: 12px; border: 1px solid #ccc; border-radius: 5px; font-size: 16px; box-sizing: border-box; }
.ppa-input-group input:focus { border-color: #1a5f7a; outline: none; box-shadow: 0 0 0 2px rgba(26,95,122,0.2); }
.ppa-btn { background: #c88d00; color: #fff; border: none; padding: 15px 30px; font-size: 18px; font-weight: 700; border-radius: 5px; cursor: pointer; width: 100%; transition: background 0.3s ease; }
.ppa-btn:hover { background: #a67500; }
.ppa-results { margin-top: 30px; padding: 25px; background: #f9f9f9; border-radius: 8px; display: none; border-left: 5px solid #1a5f7a; }
.ppa-result-row { display: flex; justify-content: space-between; margin-bottom: 15px; padding-bottom: 10px; border-bottom: 1px dashed #ddd; }
.ppa-result-row:last-child { border-bottom: none; margin-bottom: 0; }
.ppa-result-label { font-weight: 600; }
.ppa-result-value { font-weight: 700; color: #1a5f7a; font-size: 18px; }
.ppa-article { padding: 30px; border-top: 1px solid #e1e1e1; background: #fff; }
.ppa-article h2 { color: #1a5f7a; font-size: 24px; margin-top: 0; }
.ppa-article h3 { color: #333; font-size: 20px; margin-top: 25px; }
.ppa-article p { margin-bottom: 15px; }
.ppa-article ul { margin-bottom: 15px; padding-left: 20px; }
.ppa-article li { margin-bottom: 8px; }
.highlight { color: #c88d00; font-weight: bold; }
function calculatePPASavings() {
var annualGen = parseFloat(document.getElementById('annualGeneration').value);
var utilRate = parseFloat(document.getElementById('utilityRate').value);
var ppaRateStart = parseFloat(document.getElementById('ppaRate').value);
var ppaEsc = parseFloat(document.getElementById('ppaEscalator').value) / 100;
var utilInf = parseFloat(document.getElementById('utilityInflation').value) / 100;
var years = parseInt(document.getElementById('termYears').value);
if (isNaN(annualGen) || isNaN(utilRate) || isNaN(ppaRateStart) || isNaN(years)) {
alert("Please enter valid numerical values.");
return;
}
var totalPpaCost = 0;
var totalUtilCost = 0;
var year1Savings = 0;
var year1Payment = 0;
var currentPpaRate = ppaRateStart;
var currentUtilRate = utilRate;
for (var i = 0; i < years; i++) {
var yearlyPpa = annualGen * currentPpaRate;
var yearlyUtil = annualGen * currentUtilRate;
if (i === 0) {
year1Savings = yearlyUtil – yearlyPpa;
year1Payment = yearlyPpa;
}
totalPpaCost += yearlyPpa;
totalUtilCost += yearlyUtil;
// Apply escalators for next year
currentPpaRate *= (1 + ppaEsc);
currentUtilRate *= (1 + utilInf);
}
var lifetimeSavings = totalUtilCost – totalPpaCost;
var avgAnnual = lifetimeSavings / years;
// Update UI
document.getElementById('year1Savings').innerText = "$" + year1Savings.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('year1Payment').innerText = "$" + year1Payment.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('lifetimeSavings').innerText = "$" + lifetimeSavings.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('avgAnnualSavings').innerText = "$" + avgAnnual.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('ppaResults').style.display = 'block';
// Smooth scroll to results
document.getElementById('ppaResults').scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}
Solar PPA Savings Calculator
Estimate your savings by switching to a Power Purchase Agreement
Year 1 Savings:
$0.00
Year 1 PPA Payment:
$0.00
Total Lifetime Savings:
$0.00
Average Annual Savings:
$0.00
Understanding Your Power Purchase Agreement (PPA)
A Solar Power Purchase Agreement (PPA) is a financial arrangement in which a third-party developer designs, finances, installs, and maintains a solar energy system on a customer's property at little to no upfront cost. Instead of buying the panels, the customer agrees to purchase the energy generated by the system at a fixed per-kWh rate.
How This PPA Calculator Works
This calculator compares the cost of energy you would buy from your utility company against the cost of energy purchased through a PPA over the life of the contract. It accounts for two critical factors that often confuse homeowners:
- The PPA Escalator: Many PPA contracts include an "escalator" clause, meaning your PPA price per kWh increases by a set percentage (usually 1% to 3%) every year.
- Utility Rate Inflation: Historically, utility companies increase their rates annually. This calculator defaults to a 3.5% national average, but you can adjust this based on your local utility's history.
Example Calculation
Imagine a home that uses 10,000 kWh per year. If your utility charges $0.20/kWh, your annual bill is $2,000. If a PPA provider offers you a rate of $0.15/kWh with a 0% escalator:
- Year 1 Savings: ($0.20 – $0.15) × 10,000 = $500.
- Long Term: As the utility rate rises to $0.28 over 10 years while your PPA stays at $0.15, your annual savings grow significantly.
Key Benefits of a Solar PPA
PPAs are popular because they remove the barriers to entry for solar energy. Benefits include:
- $0 Down: No significant upfront capital investment is required.
- Maintenance Free: Because the PPA provider owns the system, they are responsible for all repairs and monitoring.
- Immediate Savings: Most PPAs are structured to ensure the per-kWh rate is lower than your current utility rate from day one.
- Predictability: You know exactly what you will pay for power for the next 20-25 years, protecting you against volatile energy market spikes.