1. Definition of photoelectric conversion efficiency
Photoelectric conversion is the process of directly converting solar radiation energy into electrical energy through the photovoltaic effect. The principle of this process is that photons transfer energy to electrons to make them move to form an electric current. There are two ways to solve this process. The most common one is to use a solid device with silicon as the main material, and the other is to use photosensitive dye molecules to capture the energy of photons. After the dye molecule absorbs the photon energy, it separates the negatively charged electrons from the positively charged holes in the semiconductor.
The photoelectric conversion efficiency, that is, the incident monochromatic photon-electron conversion efficiency (in English abbreviation IPCE), is defined as the ratio of the number of electrons Ne generated in the external circuit per unit time to the number of incident monochromatic photons Np per unit time. See the formula for its mathematical expression:
The units used for Isc, l and Pin are μAcm-2, nm and Wm-2, respectively.
2. Calculation method of photovoltaic module conversion efficiency
When the irradiation intensity is 1000M/cm2: the solar working temperature is 25℃±2℃, the maximum output power divided by the sunlight intensity multiplied by the solar panel's light absorption area multiplied by 100%.
Solar cell efficiency = (open circuit voltage x short-circuit current x fill factor) / cell area x illuminance x100%
In fact, the conversion efficiency of photovoltaic modules is affected by many factors such as the material type of the photovoltaic module, light time, light intensity, installation angle, surface cleanliness, and battery attenuation.
All photovoltaic modules are calculated in the same way whether it is home solar panels or foldable solar panels.