Design a Resilient Microgrid for Puerto Rico
Part 1: Engage (Anchoring Phenomenon)
In recent years, communities in Puerto Rico have faced extended power outages following severe hurricanes. Without electricity, essential services such as medical devices, refrigeration for medicine and food, and communication systems are severely compromised. To build resilience, communities are designing microgrids—localized power networks that can generate and store their own energy, operating independently from the main grid during an emergency.
Task: You are tasked with designing a microgrid for a small Puerto Rican community. Your goal is to configure the solar array, battery storage, and power loads to survive a 72-hour hurricane simulation with 0 blackout hours.
Questions to Consider:
- What challenges do communities face when trying to keep the power on during a multi-day storm?
- How does energy storage (batteries) complement renewable energy generation (solar)?
- Write down two “need to know” questions you have about balancing power generation and power usage during a storm.
Part 2: Explore (Simulation Investigation)
Open the Puerto Rico Resilient Microgrid Simulation. Take a few minutes to familiarize yourself with the interface.
Variables you can control:
- Solar Array Size (kW): The maximum power generated during peak sunlight.
- Battery Capacity (kWh): The total energy the batteries can store.
- Critical Load (kW): The power needed for essential survival services (e.g., medical devices, emergency comms).
- Non-Critical Load (kW): Power used for less essential items (e.g., extra lighting, AC).
- Auto Load Shedding: A system that automatically shuts off the non-critical load when the battery level drops below 30%.
Outputs to observe:
- Grid Status: Normal or Blackout.
- Blackout Hours: The total hours the critical load was not met.
- Min Battery Level: The lowest charge percentage the battery reached during the 72 hours.
- Simulation Chart: A graph tracking battery percentage and net power over time.
Investigation 1: Baseline Testing
Set the simulation to the following defaults:
- Solar Size: 20 kW
- Battery Capacity: 50 kWh
- Critical Load: 2.0 kW
- Non-Critical Load: 5.0 kW
- Auto Load Shedding: OFF
Run the simulation. Record your results in the data table below.
Investigation 2: System Optimization
Your goal is to achieve 0 blackout hours while minimizing excess (unused or wasted) capacity to save costs. Run at least three different trials adjusting the variables.
Data Table:
| Trial | Solar Size (kW) | Battery Cap (kWh) | Critical Load (kW) | Non-Critical Load (kW) | Load Shedding | Blackout Hours | Min Battery % |
|---|---|---|---|---|---|---|---|
| 1 (Base) | 20 | 50 | 2.0 | 5.0 | OFF | ||
| 2 | |||||||
| 3 | |||||||
| 4 |
Part 3: Explain (Sensemaking)
Use your data and observations from the simulation to answer the following questions:
- System Identification: Describe the system being modeled in this simulation. What are the boundaries of this system?
- Scientific Principles: What scientific relationships between energy generation (solar), energy storage (battery), and energy consumption (loads) govern whether the microgrid experiences a blackout?
- Evaluating Trade-offs: Compare Trial 1 to your successful trial. How did the use of “Auto Load Shedding” affect the survival of the microgrid? Why is this considered a “trade-off” for the residents?
Part 4: Elaborate/Evaluate (Argumentation & Modeling)
Now that you have optimized a solution, evaluate the broader impacts of your design.
- Negative Consequences: Proposing a massive solar array (100 kW) and maximum battery capacity (200 kWh) would easily survive the storm. What are the possible negative consequences (e.g., social, environmental, economic) of over-engineering the solution that might outweigh the benefits?
- Simulation Limitations: All models have limitations. Identify at least two real-world variables or factors that this computer simulation does not account for when modeling a microgrid during a hurricane.
- Final Recommendation: Write a brief, evidence-based recommendation to the community council defending your final microgrid configuration. Reference specific data (variables and outputs) from your trials to prove why your solution is the most effective and balanced option.
Teacher Notes & Alignment
- Targeted NGSS PE: HS-ETS1-4: Use a computer simulation to model the impact of proposed solutions to a complex real-world problem with numerous criteria and constraints on interactions within and between systems relevant to the problem.
- Science and Engineering Practice (SEP): Using Mathematics and Computational Thinking (Use mathematical models and/or computer simulations to predict the effects of a design solution on systems and/or the interactions between systems).
- Disciplinary Core Idea (DCI): ETS1.B: Developing Possible Solutions (Computers are useful for a variety of purposes, such as running simulations to test different ways of solving a problem…).
- Crosscutting Concept (CCC): Systems and System Models (Models can be used to simulate systems and interactions…).
- Evidence Statements Assessed:
- 1a. Students identify the problem, the system/boundaries, user variables, and scientific principles.
- 2a. Students use the simulation to select logical inputs and simulate effects of solutions.
- 3b/c/d. Students interpret results, identify negative consequences of solutions, and identify the simulation’s limitations.