Lesson 4: Investigate the Impact of Different Light Intensities and Spectra on Solar Energy generation Efficiency
PREPARATION
ENGAGE
Spark curiosity about how light properties affect solar energy storage.
Core Teaching Steps:
Show images of solar panels in different environments:
Ask: "Why might a solar panel charge a battery faster in direct sunlight than on a cloudy day? Could the color of light matter?"
Initial Predictions:
Present a table comparing light intensity (lux) and battery charging time:
Prompt discussion: “How do you think light color (spectrum) and brightness (intensity) affect the power a solar panel produces?”
EXPLORE
Use controlled experiments to explore the quantitative relationship between light intensity and solar panel voltage. Students will adjust light distance to change intensity, collect data via light sensors and voltage modules, and undergo a full inquiry process ("hypothesis testing → data recording → preliminary analysis") to develop experimental design and measurement skills.
Core Teaching Steps:
connection:
Code:
Data Collection and Recording:
Use a phone flashlight as the light source for testing.
Start at 10cm, record light level and voltage (V) with 3 repetitions.
Wait 20 seconds for stable readings after each distance adjustment.
Guided Observation:
"When distance doubles, do intensity and voltage decrease proportionally? Why or why not?"
EXPLAIN
Facilitate group discussions and data presentations to guide students in constructing scientific explanations based on evidence. Using a "Claim-Evidence-Reasoning" framework, they will analyze the intensity-voltage relationship, link it to photon theory, and refine conclusions through critical thinking.
Core Teaching Steps:
Data Visualization and Trend Analysis:
Groups present light level(read from light sensor)-voltage line graphs with trend lines.
Use the formula to predict voltage at 2000(analog read). How would you verify it?
Scientific Principle Connection:
Structure explanations:
"We found a ____ relationship (e.g., positive correlation) between intensity and voltage, as shown by ____ (evidence: data trend). This occurs because ____ (principle: intensity determines photon quantity and electron excitation)."
Critical discussion:
"How might using different solar panel types (monocrystalline vs. polycrystalline) affect this relationship?"
CHALLENGE
Build on the intensity experiment to explore spectral effects. Using LEDs in different color, compare voltage data across spectra, and understand solar panels’ wavelength-specific absorption. This fosters multi-variable experimental design and interdisciplinary thinking.
Core Teaching Steps:
Code:
Experimental Design and Variable Control:
Independent Variable: Color of light (red/blue).
Dependent Variable: Voltage output (V) of the solar panel.
Controlled Variables:
1. Distance between LED and solar panel fixed at 3 cm (measured with a ruler).
2. Ambient light shielding (close curtains, turn off classroom lights).
3. Experimental duration (5 seconds per measurement, read after voltage stabilizes).
Operation Procedure:
1.Press button A, illuminate the solar panel with red light, and record the voltage value displayed on Unihiker's screen.
2.Remove the LEDs away, wait 2 seconds for ambient light to dissipate.
3.Press button B, illuminate the solar panel with blue light, and record the voltage value.
4.Repeat the above steps 3 times to obtain three sets of data for red light and blue light.
Recording Table:
Core Conclusion:
Solar panels have higher energy conversion efficiency for blue light, generating greater voltage under the same intensity.
Real-World Connection:
"In solar cell design, how can this characteristic be used to improve power generation efficiency?"
(Answer hint: Adopt multi-layer material structures to absorb light of different spectra respectively)
CONCLUSION
The teacher will now summarize the lesson and guide the students to disconnect and neatly pack away all equipment before returning it.
program-L4.zip 
