Solar Cells

Finding the maximum power point

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Solar cells separate light-made electron–hole pairs with a junction’s built-in field.
• Power peaks at the maximum power point, below the open-circuit voltage.
• Band-gap physics limits single-junction cells to about 33%; real panels reach about 20–23%.

Steps

1. A diode in sunlight
2. The maximum power point
3. Efficiency
4. Why not 100%?
5. Fill factor
6. A rooftop’s worth