חישוב עלויות וחיסכון ב-TypeScript

// Solar configuration, from buildingInsights.solarPotential.solarPanelConfigs
let panelsCount = 20;
let yearlyEnergyDcKwh = 12000;

// Basic settings
let monthlyAverageEnergyBill: number = 300;
let energyCostPerKwh = 0.31;
let panelCapacityWatts = 400;
let solarIncentives: number = 7000;
let installationCostPerWatt: number = 4.0;
let installationLifeSpan: number = 20;

// Advanced settings
let dcToAcDerate = 0.85;
let efficiencyDepreciationFactor = 0.995;
let costIncreaseFactor = 1.022;
let discountRate = 1.04;

// Solar installation
let installationSizeKw: number = (panelsCount * panelCapacityWatts) / 1000;
let installationCostTotal: number = installationCostPerWatt * installationSizeKw * 1000;

// Energy consumption
let monthlyKwhEnergyConsumption: number = monthlyAverageEnergyBill / energyCostPerKwh;
let yearlyKwhEnergyConsumption: number = monthlyKwhEnergyConsumption * 12;

// Energy produced for installation life span
let initialAcKwhPerYear: number = yearlyEnergyDcKwh * dcToAcDerate;
let yearlyProductionAcKwh: number[] = [...Array(installationLifeSpan).keys()].map(
  (year) => initialAcKwhPerYear * efficiencyDepreciationFactor ** year,
);

// Cost with solar for installation life span
let yearlyUtilityBillEstimates: number[] = yearlyProductionAcKwh.map(
  (yearlyKwhEnergyProduced, year) => {
    const billEnergyKwh = yearlyKwhEnergyConsumption - yearlyKwhEnergyProduced;
    const billEstimate =
      (billEnergyKwh * energyCostPerKwh * costIncreaseFactor ** year) / discountRate ** year;
    return Math.max(billEstimate, 0); // bill cannot be negative
  },
);
let remainingLifetimeUtilityBill: number = yearlyUtilityBillEstimates.reduce((x, y) => x + y, 0);
let totalCostWithSolar: number =
  installationCostTotal + remainingLifetimeUtilityBill - solarIncentives;
console.log(`Cost with solar: $${totalCostWithSolar.toFixed(2)}`);

// Cost without solar for installation life span
let yearlyCostWithoutSolar: number[] = [...Array(installationLifeSpan).keys()].map(
  (year) => (monthlyAverageEnergyBill * 12 * costIncreaseFactor ** year) / discountRate ** year,
);
let totalCostWithoutSolar: number = yearlyCostWithoutSolar.reduce((x, y) => x + y, 0);
console.log(`Cost without solar: $${totalCostWithoutSolar.toFixed(2)}`);

// Savings with solar for installation life span
let savings: number = totalCostWithoutSolar - totalCostWithSolar;
console.log(`Savings: $${savings.toFixed(2)} in ${installationLifeSpan} years`);
SolarPotentialSection.svelte