Ballpark guess at CO2 emissions from wasted boiling of water

co2e_wasted_boiling.py

"""
Tool to calculate the average additional CO2e emissions
from the instruction "boil half a kettle",
rather than some slightly more precise figure ("boil 200ml").

Naturally, not everyone will follow this -- we're all busy people --
so we will have to assume not all of these wasted emissions
can be reduced.

This is targetted at a recipe-delivery service company;
naturally the numbers would need to be replaced with the company's own data.

Forgive the incredible overprecision in printed numbers!
Tweaking Noether's unit display to be nicer is... one of many priorities.

To run, grab Python 3.11 and `pip install noether`.
"""

from noether import *


#% volumetric energy to boil water

water_boiling_point = celsius(99.98)
water_enth_vaporiz = 2257 * kJ / kg
water_heat_capacity = 4184 * J / (kg * K) # assume constant
def energy_boil(T: temperature) -> specific_energy:
    return (water_boiling_point - T) * water_heat_capacity + water_enth_vaporiz

T_room = celsius(20, 2)
E_boil = energy_boil(T_room) / (milliliter / gram)

#% assumptions for the UK as a whole

recipe_rate = 1_000_000 / week
print(f"Assuming {recipe_rate * week} recipes are cooked per week...")
recipe_boil = ml(150, 50)
print(f"Assuming the avg recipe calls for {recipe_boil @ ml} boiled water...")

E_half_kettle = E_boil * liter(1, 0.2)
E_typ_recipe = E_boil * recipe_boil
E_wasted = E_half_kettle - E_typ_recipe

E_waste_rate = recipe_rate * E_wasted

# https://ourworldindata.org/grapher/carbon-intensity-electricity?tab=chart&country=~GBR
CO2e_rate_UK = gram(255, 5) / kWh
CO2e_waste_rate = E_waste_rate * CO2e_rate_UK

print("the CO2e waste rate is:")
print(' ',CO2e_waste_rate @ (gram / second))
print('=', CO2e_waste_rate @ (ton / year))