calculations/emissions.js

  1. /**
  2.  * Emission related calculations
  3.  * @module
  4.  * @since 0.0.3
  5.  */
  7. import { gallonsToLitres, mpgToL100km, milesToKM } from '../maths/conversions';
  8. import { co2_kg_per_litre } from '../maths/constants';
  9. import { roundToDP } from '../maths/util';
  11. /**
  12.  * co2 by a number of units of fuel
  13.  * @param {number} num_amount Quantity of fuel
  14.  * @param {string} from_unit What unit the fuel quantity is in
  15.  * @param {string} fuel_type Type of fuel i.e diesel or petrol
  16.  * @returns {number} Total kg of CO2 for fuel supplied
  17.  */
  18. const getCo2ByAmountOfFuel = (
  19.     num_amount,
  20.     from_unit,
  21.     fuel_type,
  22. ) => {
  23.     let _num_amount = num_amount;
  25.     // convert to litres
  26.     if (from_unit === 'gallons') {
  27.         _num_amount = gallonsToLitres(_num_amount);
  28.     }
  30.     return roundToDP((_num_amount * co2_kg_per_litre[fuel_type]), 7);
  31. };
  33. /**
  34.  * co2 by amount of money spent
  35.  * @param {number} num_amount Quantity of fuel
  36.  * @param {string} from_unit What unit the fuel quantity is in
  37.  * @param {string} fuel_type Type of fuel i.e diesel or petrol
  38.  * @returns {number} Total kg of CO2 for fuel supplied
  39.  */
  40. const getCo2ByAmountOfMoney = (
  41.     pounds_spent,
  42.     pence_per_litre,
  43.     fuel_type,
  44. ) => {
  45.     // get number of litres used by calculating amount spent in pence divided by
  46.     // cost in pence per litre
  47.     const num_litres = (pounds_spent * 100) / pence_per_litre;
  49.     // calculate co2 from litres used
  50.     return getCo2ByAmountOfFuel(num_litres, 'litres', fuel_type);
  51. };
  53. /**
  54.  * co2 by amount of fuel consumed
  55.  * @param {number} num_distance Miles or KM travelled
  56.  * @param {string} distance_unit Miles or KM
  57.  * @param {number} num_consumption Quantity of fuel
  58.  * @param {string} consumption_unit l/100km or mpg
  59.  * @param {string} fuel_type Type of fuel i.e diesel or petrol
  60.  * @returns {number} Total kg of CO2
  61.  */
  62. const getCo2ByDistance = (
  63.     num_distance,
  64.     distance_unit,
  65.     num_consumption,
  66.     consumption_unit,
  67.     fuel_type,
  68. ) => {
  69.     let _num_consumption = num_consumption;
  70.     let _num_distance = num_distance;
  72.     // convert to l100km if mpg
  73.     if (consumption_unit === 'mpg') {
  74.         _num_consumption = mpgToL100km(_num_consumption);
  75.     }
  77.     // convert to km from if miles
  78.     if (distance_unit === 'miles') {
  79.         _num_distance = milesToKM(_num_distance);
  80.     }
  82.     // find out how many litres have been used
  83.     const num_litres = _num_distance * (_num_consumption / 100);
  85.     // calculate co2 from litres used
  86.     return getCo2ByAmountOfFuel(num_litres, 'litres', fuel_type);
  87. };
  89. export {
  90.     getCo2ByAmountOfFuel,
  91.     getCo2ByAmountOfMoney,
  92.     getCo2ByDistance,
  93. };