To calculate fill factor, you need to divide the maximum possible power output of a cell by its actual power output. This will give you a measurement that you can use to assess the performance of your solar cell. Solar cells with a higher fill factor have a higher efficiency and are therefore more desirable. How to Calculate Fill Factor?
Fill factor is often referred to as a representation of the squareness of the IV curve. One way to picture P max, is as the maximum rectangular area that can fit inside the J-V curve of your solar cell. If J SC x V OC defines another rectangle, then FF represents how close these two rectangles are to one another.
Therefore, the FF is most commonly determined from measurement of the IV curve and is defined as the maximum power divided by the product of I sc *V oc, i.e.: The equation for a solar cell is: I = I L − I 0 [exp (V n V t) − 1]
The "fill factor", more commonly known by its abbreviation "FF", is a parameter which, in conjunction with V oc and I sc, determines the maximum power from a solar cell. The FF is defined as the ratio of the maximum power from the solar cell to the product of V oc and I sc so that:
The Fill Factor, along with other parameters like efficiency and the maximum power point, affects the overall performance and output of a solar panel. A higher FF typically results in a better performing solar panel. Can the Fill Factor of a solar panel change over time?
The maximum theoretical FF from a solar cell can be determined by differentiating the power from a solar cell with respect to voltage and finding where this is equal to zero. Hence: giving: V M P = V O C − n k T q l n (q V M P n k T + 1) It is an implicit equation, but it converges rapidly with iteration.