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F12.5 Technology and the environment

Technology and society · GCSE · OCR J277 1.6.1, AQA 8525 3.8, Edexcel 1CP2 5.1.1 · about 15 min

BugBotLab

What this lesson is about

Making, running and disposing of devices: materials, data centres, e-waste and what helps.

Questions 5 marks in all

  1. [1 mark]When is most of a phone's carbon footprint created?

    1. AWhile it is being manufactured
    2. BWhile it is charging
    3. CWhile it is being recycled
    4. DWhile it is in a shop
    Answer: A. Mining and manufacture dominate, which is why keeping a device longer helps most.

  2. [1 mark]What is e-waste?

    1. ADiscarded electrical and electronic devices
    2. BWasted electricity
    3. CSpam email
    4. DUnused files
    Answer: A. It is the fastest growing household waste stream.

  3. [1 mark]Why are data centres an environmental concern?

    1. AThey use a great deal of electricity, much of it for cooling
    2. BThey are noisy
    3. CThey take up farmland only
    4. DThey use no electricity
    Answer: A. The carbon depends on how that electricity is generated.

  4. [1 mark]15 devices of 60 W run for 3 hours. How many kWh is that?

    Answer: 2.7. 60 × 3 × 15 = 2700 Wh = 2.7 kWh.

  5. [1 mark]How does efficient code help the environment?

    1. AIt does the same job with less processing, so less electricity
    2. BIt makes files smaller only
    3. CIt needs more servers
    4. DIt has no effect
    Answer: A. Multiplied across every machine that runs it, the saving is real.

The task: the classroom's footprint

For each device in devices (a name, its watts, and how many hours it runs a day), work out the energy for a 190-day school year across count of them. Print <name>: <kwh> kWh rounded to 1 decimal place, then at the end total: <kwh> kWh, cost: £<n> at 28p a unit rounded to 2 decimal places, and carbon: <n> kg CO2 at 190 g a unit, rounded to the nearest whole number.

# the two lines every program starts with: the commands, then the robot
from bugbot import *
connect()

days = 190
count = 15                      # how many of each device the class has
# name, watts, hours a day
devices = [("laptop", 50, 5), ("robot charging", 8, 1), ("projector", 220, 4)]

The hint students can ask for: Energy for one device is its watts times its hours times the days times how many there are, converted from watt-hours to kilowatt-hours. Add them up, then turn the total into money and into carbon with the rates given.

A solution

from bugbot import *
connect()
days = 190
count = 15
devices = [("laptop", 50, 5), ("robot charging", 8, 1), ("projector", 220, 4)]
total = 0
for name, watts, hours in devices:
    kwh = watts * hours * days * count / 1000
    total = total + kwh
    print(f"{name}: {kwh:.1f} kWh")
print(f"total: {total:.1f} kWh")
print(f"cost: £{total * 0.28:.2f}")
print(f"carbon: {round(total * 190 / 1000)} kg CO2")

Any program that meets the task's checks is marked correct in the simulator; this is one way, not the only way.