Course:PHYS100/Energy Costs: Travel Mugs vs Paper Cups
Problem Statement:
- Comparing two types of coffee cups commonly used at coffee shops: travel mugs and paper cups supplied by the store.
- This project investigates how much energy is used to make paper cups compared to the amount to make travel mugs.
- We will investigate how much an individual's carbon footprint is reduced by using travel mugs compared to paper cups.
- We will calculate the energy saved over the span 6 months, when comparing travel mugs to paper cups.
Relevant Physics:
- Energy consumption during production of travel mugs vs paper cups.
- Energy conservation by using travel mugs instead of paper cups.
Clear model:
- We will figure out how much energy it takes to manufacture paper cups and travel mugs.
- Then we will calculate how much energy would be conserved by using travel mugs vs paper cups over a span of 6 months.
Assumptions:
- The two types of coffee cups are the same size.
- Subjects consume coffee five times a week for 6 months.
- Stainless steel travel mug.
- Paper cup has no lid or sleeve.
Correct Calculations:
Energy Consumption of a Paper Cup
Energy Consumption of a Travel mug
Paper cups used during 6 months:
- 5 days x 24 weeks = 120 cups used in 6 months
- One travel mug would be used over the span of 6 months
Energy cost of manufacturing cups during the span of 6 months:
- Paper cups: 1,457,000 J x 120 cups = 174,840,000 J
- Travel mugs (only needed to be manufactured once): 103,750,000 J
- Total saved: 174,840,000 J - 103,750,000 J = 71,090,000 J
Energy Cost of disposing at the end of 6 months:
- Paper cups: 2250 J x 120 cups = 270,000 J
- Travel mug: 29, 342 J
- Total saved: 270,000 J - 29, 342 J= 240,658 J
Thought and Interpretation of Results:
The travel mug is clearly more environmentally friendly if your are a frequent coffee drinker. However since the manufacturing costs of the travel mug is so high there could be some cases that using a paper cup would be more efficient.
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