| Condition | Intensity (percentage of full sun) |
| Full sun panel square to sun | 100% |
| Full sun panel at 45° angle to sun | 71% |
| Light overcast | 60–80% |
| Heavy overcast | 20–30% |
| Inside window, single pane, double-strength 91% glass, window, and module square to sun Inside window, double pane, double-strength glass, window, and module square to sun | 84% |
| Inside window, single pane, double-strength glass, and window module at 45° angle to sun | 64% |
| Indoor office light (at desk top) | 0.4% |
| Indoor light (store lighting) | 1.3% |
| Indoor light (home) | 0.2% |
Table 1—Any of these
conditions will affect the conversion efficiency of the solar panel.