Cell efficiency Voltage and currents Maximum power point, tracking needed?
Sun angle and input power
Beacon Academy activity
2. Vocabulary
Solar cells basics
Solar panel construction Open circuit voltage predict
Short circuit current
I/V curve and max power point
Efficiency?
Angle to sun vs Isc predict and measure.
Series cells behavior. Shadowing
3. Supplies
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flashlights to shine through panels
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large solar panel
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wall power meters
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variety of smaller panels
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USB breakout modules
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4. Stations
4.1. Module construction
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Large panel
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Red panel
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Square and rectangular small panels
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Cell/panel from solar path light
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Bare cells
Open circuit voltage and construction of solar modules.
Large panel. connections to top or bottom of each cell. Predict Voc and check with measurement and label rating.
Panel is 8 x 12 = 96 cells. How are they connected?
Flashlight to see embedded wires across the top and bottom.
4.2. Angle effects
200W incandescent bulb in reflector
measure short-circuit current vs. angle
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angle
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ISC
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VOC
Light flux proportional to cosine of angle. 90deg is normal to the plane and max light flux. Short circuit current is a good proxy.
4.3. Shading effects
Panel connected to TT motor
Shade from two directions.
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Cover one of the series cells
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Cover side to shade 50% of all cells
Review series connection idea.
4.4. Incandescent source
Measure ISC and VOC of same panel but with different light sources.
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200W clear incandescent
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200W frosted incandescent
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"200W" LED bulb
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LED flood light
Measurement table:
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Source information
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bulb type
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bulb lumens
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wall power input (via )
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VOC
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ISC
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normalize to bulb rating: mA / lumen
