Campus Cup Life Cycle Comparison

ISEF Category: Environmental Engineering

Subcategory: Recycling and Waste Management  ·  Difficulty: Advanced  ·  Setup: School Lab  ·  Time: 1 to 2 Months

The Hook

A reusable cup is not always greener than a disposable one. The answer depends on how often people use it, wash it, and replace it. That makes this topic a great fit for real research, not guesswork. You can build a model that turns campus habits into environmental impact.

What Is It?

This project uses life cycle assessment, or LCA, to compare two systems from start to finish. Instead of looking only at the trash can, you look at everything that happens to a cup, from raw materials and manufacturing to transport, washing, and disposal. Think of it like tracking the full cost of a smartphone, not just the sticker price.

You will model a single-use cup system and a reusable cup system on your campus. Then you will plug in local data, like how many cups students use, how often reusable cups get washed, and how long they stay in use. That makes your results more realistic than a generic comparison.

openLCA is software that helps you build the model. ecoinvent demo data gives you background data for common materials and processes. With those tools, you can estimate impacts like greenhouse gas emissions, energy use, and waste generation.

Why This Is a Good Topic

This topic works well because it has a clear question, real data, and a strong local angle. You can test how behavior changes the outcome, which makes the project more than a simple comparison of plastic versus reusable. It connects to waste reduction, campus policy, and everyday consumer choices. You can also learn a research skill that environmental engineers use in real projects, life cycle modeling.

Research Questions

• How does the number of uses per reusable cup change its total environmental impact compared with single-use cups?
• What is the effect of wash frequency on the greenhouse gas emissions of a reusable cup system?
• Does locally measured campus cup usage change the break-even point between single-use and reusable systems?
• To what extent do transport and washing contribute to the total impact of each cup system?
• Which material choice for a reusable cup lowers total energy use the most under the same campus habits?
• How does varying the replacement rate of reusable cups affect the model's waste reduction outcome?

Basic Materials

• Laptop or desktop computer with enough storage to run openLCA.
• openLCA software, free version.
• ecoinvent demo data or another free background database approved for class use.
• Campus or school survey form, paper or digital.
• Spreadsheet software such as Google Sheets or Excel.
• Calculator for quick checks of break-even calculations.
• Notebook for documenting assumptions and model choices.

Advanced Materials

• Laptop or desktop computer with more memory for larger LCA models.
• openLCA software.
• ecoinvent demo data or licensed dataset access if available through a school or university.
• Campus survey dataset with usage, washing, and replacement data.
• Life cycle impact assessment method package inside openLCA.
• Spreadsheet software for sensitivity tables and uncertainty summaries.
• Optional school access to a printer or poster plotter for presentation graphics.

Software & Tools

• openLCA: Builds the life cycle assessment model and compares impact categories.
• Google Sheets: Organizes survey data, assumptions, and sensitivity tables.
• Excel: Helps you sort usage data and graph break-even results.
• R: Runs sensitivity analysis and simple uncertainty checks if you want deeper statistics.
• ImageJ: Measures and crops charts or poster graphics if you export figures as images.

Experiment Steps

1. Define the exact system boundary, including which parts of the cup life cycle you will count and which you will leave out.
2. Choose one functional unit so both systems are compared on the same service, not on the same number of cups.
3. Gather local usage data from your campus so the model reflects real habits instead of generic assumptions.
4. Build baseline LCA models for the single-use and reusable options, then check that each process link makes sense.
5. Plan a sensitivity analysis that tests the variables most likely to change the answer, such as reuse rate, wash frequency, and replacement rate.
6. Compare impact categories and identify the break-even point where the reusable option becomes better under your local conditions.

Common Pitfalls

• Comparing one reusable cup to one disposable cup instead of matching the same number of drinks served.
• Ignoring washing impacts, which can make the reusable system look cleaner than it really is.
• Using generic usage assumptions that do not match your campus, which weakens the local relevance of the results.
• Mixing up system boundaries, which causes you to count some emissions in one model but not the other.
• Skipping sensitivity analysis, which leaves you with one answer but no proof that the answer holds when assumptions change.

What Makes This Competitive

A stronger project will not just report one answer. It will test how the answer changes when the campus behavior changes. You can make the work stand out by using local survey data, clear system boundaries, and a careful sensitivity analysis. A strong final project also explains where the model is uncertain and which assumptions matter most.

Project Variations

• Compare paper cups, plastic cups, and reusable cups under the same campus use pattern.
• Test how different washing methods change the impact of a reusable cup system.
• Compare commuter-heavy and dorm-heavy campus usage to see how behavior shifts the break-even point.

Learn More

• openLCA Documentation: Search the openLCA user guides and tutorials for help building models and reading impact results.
• US EPA LCA Resources: Find background pages on life cycle assessment, system boundaries, and impact categories on the EPA website.
• USGS Water Science School: Use the USGS site to understand water use terms if you include washing impacts.
• NOAA Climate.gov: Search for articles on carbon emissions, greenhouse gases, and climate basics for context.
• Google Scholar: Search for peer-reviewed papers on reusable cup life cycle assessment and campus waste systems.