(Accounts for losses due to temperature, shading, wiring, etc. Typically 75-85%)
Estimated Solar Energy Production
Daily Production: 0 kWh
Monthly Production: 0 kWh
Annual Production: 0 kWh
function calculateSolarProduction() {
var panelWattage = parseFloat(document.getElementById("panelWattage").value);
var numberOfPanels = parseFloat(document.getElementById("numberOfPanels").value);
var peakSunHours = parseFloat(document.getElementById("peakSunHours").value);
var deratingFactorPercent = parseFloat(document.getElementById("deratingFactor").value);
var errorMessageDiv = document.getElementById("errorMessage");
errorMessageDiv.innerHTML = ""; // Clear previous errors
// Input validation
if (isNaN(panelWattage) || panelWattage <= 0) {
errorMessageDiv.innerHTML = "Please enter a valid positive number for Individual Panel Wattage.";
return;
}
if (isNaN(numberOfPanels) || numberOfPanels <= 0) {
errorMessageDiv.innerHTML = "Please enter a valid positive number for Number of Solar Panels.";
return;
}
if (isNaN(peakSunHours) || peakSunHours <= 0) {
errorMessageDiv.innerHTML = "Please enter a valid positive number for Average Daily Peak Sun Hours.";
return;
}
if (isNaN(deratingFactorPercent) || deratingFactorPercent 100) {
errorMessageDiv.innerHTML = "Please enter a valid System Derating Factor between 1 and 100.";
return;
}
var deratingFactor = deratingFactorPercent / 100; // Convert percentage to decimal
// Calculations
var totalSystemSizeKWp = (panelWattage * numberOfPanels) / 1000; // Convert Wp to kWp
var dailyEnergyProduction = totalSystemSizeKWp * peakSunHours * deratingFactor;
var monthlyEnergyProduction = dailyEnergyProduction * 30.44; // Average days in a month
var annualEnergyProduction = dailyEnergyProduction * 365;
// Display results
document.getElementById("dailyProduction").innerHTML = dailyEnergyProduction.toFixed(2) + " kWh";
document.getElementById("monthlyProduction").innerHTML = monthlyEnergyProduction.toFixed(2) + " kWh";
document.getElementById("annualProduction").innerHTML = annualEnergyProduction.toFixed(2) + " kWh";
}
Understanding Your Solar Energy Production
Investing in solar panels is a significant step towards energy independence and reducing your carbon footprint. But how much electricity can your solar system actually generate? Our Solar Production Calculator helps you estimate the energy output of your photovoltaic (PV) system, giving you a clearer picture of its potential.
What is Solar Production?
Solar production refers to the amount of electrical energy (measured in kilowatt-hours, kWh) that your solar panel system generates over a specific period. This production is influenced by several key factors, from the size and efficiency of your panels to the amount of sunlight they receive and various system losses.
How the Calculator Works: Key Factors Explained
Our calculator uses a straightforward formula to estimate your system's output. Here's a breakdown of the inputs:
1. Individual Panel Wattage (Wp)
This is the power rating of a single solar panel under standard test conditions (STC). Modern residential panels typically range from 300 Wp to 450 Wp. A higher wattage means a panel can produce more electricity.
Example: A 400 Wp panel can theoretically produce 400 watts of power under ideal conditions.
2. Number of Solar Panels
The total number of panels in your array directly scales your system's potential output. More panels mean a larger system and, consequently, more electricity generation.
Example: 15 panels of 400 Wp each would create a 6,000 Wp (6 kWp) system.
3. Average Daily Peak Sun Hours (PSH)
This is arguably the most critical factor. Peak Sun Hours represent the equivalent number of hours per day when solar irradiance averages 1,000 watts per square meter. It's not simply the number of hours the sun is out, but rather a measure of the intensity and duration of effective sunlight. This value varies significantly by geographic location, season, and local weather patterns. You can often find average PSH data for your specific region online or from solar installers.
Example: A location with 4.5 PSH receives the same amount of solar energy as if it had 4.5 hours of full, direct sunlight.
4. System Derating Factor (%)
No solar system operates at 100% efficiency all the time. The derating factor accounts for various real-world losses that reduce actual production compared to theoretical maximums. These losses include:
Temperature: Panels become less efficient as they get hotter.
Shading: Even partial shading can significantly reduce output.
Wiring Losses: Resistance in cables.
Inverter Efficiency: The inverter converts DC to AC power, with some energy loss.
Dust and Dirt: Accumulation on panel surfaces.
Panel Degradation: Panels slowly lose efficiency over time.
A typical derating factor ranges from 75% to 85% (or 0.75 to 0.85). For a conservative estimate, you might use a lower percentage; for an optimistic one, a higher percentage.
Example: An 80% derating factor means your system will produce 80% of its theoretical maximum output.
Calculation Example:
Let's use the default values in the calculator:
Individual Panel Wattage: 400 Wp
Number of Solar Panels: 15
Average Daily Peak Sun Hours: 4.5 hours
System Derating Factor: 80% (0.80)
Total System Size (kWp): (400 Wp * 15 panels) / 1000 = 6,000 Wp / 1000 = 6 kWp
Daily Energy Production (kWh/day): 6 kWp * 4.5 PSH * 0.80 = 21.6 kWh/day
Monthly Energy Production (kWh/month): 21.6 kWh/day * 30.44 days/month = 657.50 kWh/month
Annual Energy Production (kWh/year): 21.6 kWh/day * 365 days/year = 7,884 kWh/year
This means your system could produce approximately 21.6 kWh per day, 657.50 kWh per month, and 7,884 kWh per year under these conditions.
Why is This Important?
Knowing your estimated solar production helps you:
Size Your System: Determine if your proposed system can meet your household's energy needs.
Financial Planning: Estimate potential savings on electricity bills and calculate payback periods.
Environmental Impact: Quantify your contribution to reducing carbon emissions.
Set Realistic Expectations: Understand the real-world output of your solar investment.
Use this calculator as a valuable tool in your solar journey, but always consult with professional solar installers for precise site-specific assessments and detailed financial projections.