GuideCalculator

How to Build a Solar Panel Calculator

Home and property calculators help homeowners plan projects, estimate costs, and make purchasing decisions. From HVAC sizing to solar panel calculations, these tools aid in home improvement planning.

What is a Solar Panel Calculator?

Home calculators often involve physical measurements, energy calculations, and cost estimation. They need to account for regional factors like climate, local costs, and building codes.

The Formula

Formulas vary by application:
HVAC Sizing: BTU = Square Footage × Climate Factor × Insulation Factor
Solar: kWh needed = Annual Usage / (Sun Hours × Panel Efficiency)
Cost: Material Cost + Labor Cost + Contingency

Code Example

JavaScript

// HVAC sizing calculator
function calculateBTU(squareFootage, climate, insulation, windows) {
  const baseRate = 20; // BTU per sq ft baseline
  const climateFactors = { cold: 1.4, moderate: 1.0, hot: 1.2 };
  const insulationFactors = { poor: 1.3, average: 1.0, good: 0.85 };

  let btu = squareFootage * baseRate;
  btu *= climateFactors[climate];
  btu *= insulationFactors[insulation];
  btu += windows * 1000; // Additional for each window

  return Math.ceil(btu / 6000) * 6000; // Round to standard sizes
}

// Solar panel calculator
function calculateSolarNeeds(annualKWh, location, panelWattage = 400) {
  const sunHours = getSunHoursForLocation(location); // Peak sun hours
  const efficiency = 0.8; // System efficiency factor

  const dailyKWh = annualKWh / 365;
  const systemKW = dailyKWh / (sunHours * efficiency);
  const panelsNeeded = Math.ceil((systemKW * 1000) / panelWattage);

  return { systemKW, panelsNeeded, estimatedCost: systemKW * 2800 };
}