Solar PV Efficiency: How to calculate the cell and module efficiency

so you know by now that the efficiency is expressed with the unit of percentage that probably for you will be somewhere in the in the 20 range for your solar cells and solar modules um so i think it would be important for you would be interesting for you to know how this value is actually calculated so what impacts the overall efficiency of the solar cell so the efficiency is described as the amount of electrical output from your cell with the unit of watts compared to the total amount of solar energy that is hitting your solar cell and then they're using the unit of square meters so the efficiency of your solar cell of your solar module is described by looking at the amount of solar power that's hitting your solar cell and then looking at how much electrical power is being is actually produced by the solar cell okay but these are all just words so let's go to the whiteboard again you know i like it and let's draw a simple overview that we can use in order to explain this topic a little bit better so this example starts with our beautiful sun it's shining at a very steady pace the sun rays are coming our way and we are assuming that the strength of the solar power is equal to 1 000 watts per square meters so every square meter of surface area is receiving a solar power of an equivalent of 1000 watts and now we're taking a complete solar panel so pv module and we're placing it directly in the sun and just for the sake of this exercise for the sake of this explanation let's assume that the total surface area of your panel so the complete module is exactly one square meter that makes this explanation very easy but now we have an empty panel right there's no solar cells on it yet it's not producing electricity yet so we choose to go for the crystalline material and we know that the cells that we'll be using in order to build our solar panel have an efficiency of 28 so we're using these crystalline cells in order to build our solar modular solar panel and we're filling the solar panel up with all these individual cells that all have an individual overall efficiency of 28 per cell now the purpose of this exercise is understanding how the efficiency of a solar panel of a photovoltaic modules being calculated right so now that we have the total amount of solar power that is hitting the solar module which is 1000 watts per square meters we know that the total surface area of our panel is one square meter and we know that the efficiency of our solar cells of our individual solar cells is 28 now that we have all these values we should be able to calculate what the electrical output of the panel is right so how much electricity will we expect to be produced by the solar manual solar module under these conditions now i think common sense would tell us that if you have a one square meter solar module you have 28 overall efficiency solar cells and you are applying a 1000 watts per square meter radiation to the module that your expected electrical output of the module would be 280 watts that will make sense right 280 watts should be expected to be produced by the solar module under these conditions um but when we actually test it it turns out that it's not true the metal module is not producing 280 watts under these given conditions and this will be true for most photovoltaic modules because the reason why you are not getting the expected electrical output is that there's a lot of inefficient inefficiency in the module there's a lot of inactive surface area in the module which is the the empty space in between the solar cells right because all that empty space is included in the one square meter but it's not producing any electricity for you all right let them shut up for a second i just want to explain to you that the content of this video is copied from the complete course of energy systems if this information is enough for you great if you want to learn more and if you want to get access to the complete course then check the information in the description below all right you go out again so let's assume so we know for sure that this module will produce less than 280 watts and just for the the purpose of this exercise let's assume a value so let's assume that instead of the 280 watts this panel under the given conditions will produce for you 220 watts of electrical output so this means that this module this panel has an overall panel and over a module efficiency of 22 percent right you're putting 1 000 watts of solar power into the panel and you're getting 220 watts out of it so the module efficiency is 22 and now you understand a very important aspect of the performance characteristics of solar panels because there is a vast difference between the efficiency of the solar cell and efficiency of the module right the module efficiency is always lower than the efficiency of this cell so i'm happy that you understand this but now because a lot of people are not aware of this why should you but it is very important to know this when you start shopping for for panels when you start looking into what kind of panels you would want to install in your system and in case you're wondering what happens to the remainder of the the solar power right because you're feeding 1000 watts to your solar panel and you're only getting 220 watts of electrical energy out of it so what happens with the remainder of the solar power well that's just being redirected in a different form of energy some of the solar radiation is just bouncing back right into the atmosphere and some of the energy is actually converted into thermal energy into heat than just being dissipated to the environment so now that you know exactly what efficiency is how it's being calculated and now that you understand exactly the difference between the efficiency of a of a cell and a module i want to run you through two examples two examples which you might come across in real life to make absolutely sure that once you start shopping for your modules for your panels that you'll be able to distinguish between the efficiency of a cell and efficiency of a module because please keep in mind so

Channel: Solar Solution

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Id: vbIN4_FSqgM

Length: 6min 43sec (403 seconds)

Published: Fri Jul 08 2022