Aiming a solar panel: output and the angle of the light

The idea

A solar panel turns light energy into electrical energy, which a fan motor turns into motion, and the panel gives less current when the light strikes it at a slant, because a tilted panel catches less of the beam: at 60° from face-on it catches half as much.

What you need

• 1 small solar panel (for example rated 2 V, 200 mA) with leads
• 1 digital multimeter with a 10 A current range and a 200 mA current range
• 1 protractor and a stand or modelling clay to hold the panel at an angle
• A sunny day, or a bright LED lamp at a fixed distance of 30 cm
• 1 small solar fan motor

How to do it

1. Set the multimeter to its 10 A current range and connect it directly across the panel to measure its current: in full sun a panel can give more than its rated 200 mA, which would overload the 200 mA range.
2. Face the panel directly at the sun or lamp (0°) and record the current. When that reading is below 200 mA, cover the panel, move the meter to its 200 mA range for finer readings and record the face-on current again.
3. Tilt the panel to 30°, 45°, 60° and 75° from face-on, recording the current at each angle on the same meter range.
4. Plot current against angle and find the angle at which the current is about half the face-on reading.
5. Connect the fan and find the smallest angle at which it stops.
6. Use the results to choose where and how to mount a solar panel for a fan in the classroom garden shed.

What you should see

The current falls as the angle grows, slowly near face-on and faster towards edge-on. The simulation's model, in which a tilted panel catches less of the beam, gives 86.6% of the face-on current at 30°, 70.7% at 45°, 50.0% at 60° and 25.9% at 75°. Measured values fall a little faster at large angles because more light reflects off the panel's cover, and outdoors light from the sky keeps some output even at 90°. The learner knows it worked when the reading at 60° is close to half the face-on reading.

What changes

What you change

angle between the panel and face-on

What you measure

panel current (mA)

What you keep the same

• the same panel and meter
• the same light source and distance
• readings taken within a few minutes

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

• A solar panel works the same at any angle (output falls as the light slants).
• Solar panels need heat, not light (they respond to light).
• Half the angle gives half the output (the fall is slow near face-on, so 45° still gives about 71%).

Safety card

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

• Science and Technology K–6 Syllabus (2017), NESA. The syllabus taught in 2026; the 2024 syllabus replaces it from 2027. Code read from the official syllabus document (DOCX) on 2026-09-22.ST3-8PW-STST3-2DP-T
• Science and Technology K–6 Syllabus (2024), NESA. Implementation from 2027, so this code describes the future syllabus. Code read from the Stage 3 content page on 2026-09-22, where its focus area holds the content group on electrical energy being transferred and transformed, including renewable energy sources.ST3-SCI-01
• Science and Technology K–6 Syllabus (2024), NESA. Implementation from 2027, so this code describes the future syllabus. Code read from the Stage 3 content page on 2026-09-22; the entry is a fair test with the variables it lists.ST3-PQU-01
• Australian Curriculum v9AC9TDE6K02

Sources

The pages the author read to write this activity.

1. www.nsw.gov.au/education-and-training/nesa/curriculum/science/science-and-technology-k-6-2017
2. curriculum.nsw.edu.au/learning-areas/science/science-and-technology-k-6-2024/outcomes
3. spark.iop.org/what-affects-output-solar-panel
4. curriculum.nsw.edu.au/learning-areas/science/science-and-technology-k-6-2024/content/stage-3/fab23dc156