Introduction
This lab simulation introduces students to real-world energy storage methods—batteries, supercapacitors, and pumped hydro—and guides them through designing an experiment to evaluate energy storage efficiency using real-world-style data. Students will not perform a physical lab. Instead, they will practice experimental design and analyze hypothetical data to draw conclusions about performance and application. This blends data literacy, systems thinking, and scientific inquiry.
Student Objectives
Students will be able to
- Describe and compare different energy storage methods.
- Calculate and compare energy storage efficiencies using provided data.
- Design a simulated experiment with clear hypotheses and controls.
- Analyze trends, variation, and trade-offs in energy storage.
- Evaluate implications of storage efficiency in the context of hydropower, solar, and wind energy systems.
Materials
- Student Handout
- Energy Storage Reading or Extended Reading (provides students with background information on Li-ion batteries, supercapacitors, and pumped hydro energy storage methods).
- Research tools (such as online access)
- Calculator (optional)
Procedure
- Introduce the challenge with a discussion on energy storage. Example opening questions include “Why is energy storage important for energy sources such as wind and solar?” and “What does ‘efficiency’ mean in the context of energy storage efficiency?”
- Review background information on three energy storage systems: Li-ion batteries, supercapacitors, and pumped hydro. Note their function, uses, and efficiency characteristics.
- Have students work through the Student Handout (individually or in groups of 2 or 3) to choose a storage method and use the design template to plan a hypothetical test of its efficiency.
- Students will most likely need some time to further research their chosen energy storage method before they write their design plan.
- Working further in the Student Handout, students will analyze a provided data table and calculate trial efficiencies and averages.
- At the end of the Student Handout are reflection questions that students will complete, discussing which systems are most efficient or most consistent, and relate their findings to real-world applications and limitations.
Answer Key
The Student Guide contains the Exploring Efficiency Lab – Student questions.
Answers will vary greatly based on the energy storage method students choose and the way they want to write the experiment procedure. Below are sample answers for the lab.
Step 1: Supercapacitor; I am choosing to investigate the supercapacitor because it charges and discharges energy very quickly, and I’m interested to learn more about the efficiency of such a powerful system.
Step 2: I think the supercapacitor will have very high efficiency (about 85-90%) because it stores energy electrostatically rather than chemically.
Step 3: Independent variable: supercapacitor; Dependent variable: energy output (kJ); Controls: input energy, room temperature, measurement equipment
Step 4: (1) Connect a supercapacitor to a regulated DC power supply. Set the power to a safe and appropriate voltage level that matches the rated voltage of the supercapacitator. (2) Attach a digital multimeter in series with the supercapacitor to measure total input energy once it is fully charged. (3) Connect the fully charged supercapacitor to a low-voltage light bulb. (4) Use the multimeter to measure the total energy output until the supercapacitor is discharged. (5) Record the values for input energy and output energy. Repeat the experiment at least three times. (6) Analyze variables and consistency by checking that input energy stays the same each time and output conditions are consistent; (7) Calculate the efficiency of each trial, and then calculate the average efficiency.
Step 5:
| Storage Method | Trial | Energy Input (kJ) | Energy Output (kJ) | Efficiency (%) |
|---|---|---|---|---|
| Supercapacitor | 1 | 1000 | 850 | 85 |
| Supercapacitor | 2 | 1000 | 870 | 87 |
| Supercapacitor | 3 | 1000 | 840 | 84 |
Step 6:
(1) The average efficiency is 85.3%.
(2) My results proved my hypothesis. I expected around 85-90% efficiency, confirming that the supercapacitor loses very little energy during storage and use.
(3) Looking at all of the data provided, the Li-ion battery had the highest average efficiency at 89.3%. This might be because chemical storage can return more energy slowly and steadily, reducing losses in some cases.
(4) Extreme temperatures; poor manufacturing quality; fast charging or overcharging; aging over time.
(5) Cost of the system; speed of energy release; size and weight; environmental impact and recyclability; safety under stress or failure; life cycle (how many times it can be charged)
(6) Supercapacitors are great for backup power systems, elevators, and flash cameras – anything that needs fast energy bursts and lots of recharge cycles.
(7) Since wind and solar produce energy intermittently, we must store excess energy when it’s available and use it later. High-efficiency systems make sure we don’t waste too much of that energy.
(8) I think hybrid systems that combine batteries and supercapacitors will be important. Batteries provide long-term energy and supercapacitors can handle sudden demands. Together, they can balance the needs of modern grids.