The Environmental Engineering Hub

In our previous postwe learned about the i-V characteristic of a solar cell. How can we simulate this characteristic in a circuit diagram? To answer this question we are going to look at the equivalent circuit of a solar cell. Let’s start with what we learned in the previous video. Here is the I-V characteristic of a solar cell. We can note the V_OC and I_SC that we described before. We can notice a few things about this plot. There is an exponential characteristic, and it is offset negatively somehow. So how can we represent this as a circuit model? Those of you with an electrical engineering background may already realize that this resembles the characteristic of a diode, and that is exactly correct. A solar cell is, in fact a diode, and if the solar cell were in the dark, it would act, electrically, just like any other diode. However, illumination of the solar cell is what offsets it as we see here. So let’s take a look at how to model this electrically.  Her

Now that we know a bit about the physical processes behind photovoltaic energy conversion, let’s take a look at the device that does this, a solar cell. In the next few posts, we will go deep into all the operating principles of solar cells. We will discuss the semiconductor physics and optics governing their behavior and you will really get a sense of how solar cells work. Nevertheless, let’s start by trying to understand an important aspect for any electrical component, the current-voltage or “i-V” characteristic of the solar cell. Here we see a basic solar cell schematic. There are many different components and layers and you will become familiar with the properties and purposes of all these layers throughout the blog. All you need to know for this post is that a solar cell can take energy from illumination, and convert it into electrical energy in an external circuit. This post’s objective is to answer ‘what’. You will need to go through the rest of the course to u

We have discussed some important properties of light and characteristics of the radiation of light by our sun. In this post, we will focus on converting that light to electrical energy. This is done using the photovoltaic effect. Photovoltaics covers the direct conversion of sunlight into electrical energy, by a semiconductor material. The term photovoltaics is derived from the Greek word ‘phos’ which means light, and volt, which refers to electricity, specifically voltage. Volt is a reference to the Italian physicist Alessandro Volta, who invented the battery photovoltaic effect that was discovered in 1839, by the French physicist Emond Becquerel. At the age of 19 Becquerel created the first photovoltaic cell by illuminating platinum electrodes, coated with silver chloride in an acid solution. This device was the first to convert light into electricity. The photovoltaic effect occurs through the generation of a potential difference at the junction of two different material