Solar Panel Efficiency: What Is It? — and Does It Matter?

In this video, we'll look at two things  one is what is solar panel efficiency   and the second is how much does it matter So first thing solar panel efficiency what is it  solar panel efficiency refers to the amount of the   sunlight or a radiation um that falls on a solar  panel that the panel is able to convert into   uh usable electricity so the most efficient solar  panel on the market say a SunPower X22 series   you know is probably um I think in in the order  of 22.7 efficiency um so what that means is that   effectively 22 of the energy that's in um the  sunlight the radiation energy that's within   the sunlight that falls on that panel it's able  to convert to electricity a cell developed just   to sell it hasn't become a panel yet um by the  National Renewable Energy Labs in Colorado that   in I think was 38 percent efficient there are  advancements all the time but at the moment   in production standard panels you know the top  the most efficient currently approved panel   is about 22.7 there's quite a lot of the good tier  one brands that are around 19 and a half to 21   and you know a couple of the big  Chinese manufacturers have actually   announced that they've developed cells  that are also around the 22, 22 and a half percent efficiency level and they'll probably be  available in their production models in 2000 and   late 2021 I would have thought that's  what solar panel efficiency is it's the   measure of how much of the energy  a panel receives it can turn into usable electricity the next question that really  matters is how important is that and when is it   important is it always important is it so is it  important sometimes now I would argue that solar   panel efficiency is not as important as it is  often sort of hyped up to be by solar salesman   the reason I would say that is because the  way they measure efficiency of a panel is they   shine you know a kilowatt of solar  energy or radiation at a solar panel   at 25 degrees celsius and they measure what  proportion of that energy that panel is able to   you know convert into electricity  so that's how they measure standard   test conditions based on that they'll  then rate a panel at a certain wattage   that's the 360 SunPower here and this is a 360 LG  over here now um slightly different efficiencies   but these panels will produce the same amount  of power all things being equal about the   other specs of the panel in terms of things like  temperature coefficient um and the like um which   does vary slightly between these panels SunPower  has also has a very good temperature coefficient   which means that as it heats up its output  degrades slower than than a different panel that   has a slightly different temperature coefficient  but the the main thing to note about that is   you know these panels may well have different  cells of different efficiency within them   but they're both 360 watt panels which means  in the same amount of sunlight point on them   pointed on them at 25 degrees celsius they'll  produce exactly the same amount of power   so if we extrapolate that out and we're talking  about an average residential size system of say   8 or 10 kilowatts or whatever then you know if  you have a 10 kilowatt system you're quoted with   a 22 percent efficient panel and a 10 kilowatt  system you're quoted with a 20 efficient panel   then those two systems will produce exactly  the same amount of power because the efficiency   is already taken into account in the rating of the  panel at a certain wattage so what that means is   what's it really worth and what you know why is  efficiency really worth more now the only time   when that efficiency is really of value to you  is when you have a limited space on your roof if   you have the same 10 kilowatt system using these  two different panels of different efficiency   the only difference will be the one that's more  efficient will be a slightly smaller footprint   if the two panels of different efficiency receive  the same amount of sunlight so they're sitting in   the same plane same at atmospheric conditions  same amount of sunlight the two 360 watt panels   of different efficiencies will produce the same  amount of power but the 360 watt panel that's most   efficient will take up a slightly smaller in that  case a 10 smaller footprint so that is a value   where you have a very tight roof space because  it may be the difference between getting   10 kilowatts on your roof and 11 kilowatts  however for most people either you don't need that   size system to power your house or you have  more than enough roof space to power it and so   I would argue that for most people it's not worth  paying a huge premium for efficiency and that's   really the point of this the point I wanted to  make and the reason I made this video is because   all things being equal efficiency is good more  efficient I guess is better because it it's it's   no more power my 10 kilowatt array is still  the same amount of power but it's slightly   smaller I guess so that's kind of nice but it's  not worth paying a massive premium for because   it really doesn't matter that much so that's  what I have to say about solar panel efficiency   if you go to SolarReviews.com and then type  solar panel efficiency you'll find articles   that go into this topic in more detail as always  we recommend people going over to our website   and using our online solar calculator it  will from just your address your power spend   it will work out how many solar panels  you would need to offset your bill   it'll even show them to you on your roof and  it can also get estimates from one of the   many great local family-owned solar companies  around the the country I think there's six or   seven hundred solar companies that we have that  provide quotes for our site so um these guys   you know know a lot about solar and you know  most of them are great companies that are   will give you a great service and and you'll enjoy  dealing with them so all the best for now goodbye

Channel: SolarReviews

Views: 22,058

Keywords: solar panel efficiency, what is the efficiency of solar panels, solar efficiency, average efficiency of solar panels, solar panel efficiency 2021, what does solar panel efficiency mean, solar power efficiency, solar panel efficiency explained, solar panel efficiency calculation, solar power efficiency 2021, what is solar panel efficiency, solar energy efficiency, solar energy efficiency 2021, does solar panel efficiency matter, what effects solar panel efficiency

Id: fFICdZ9I2wg

Length: 7min 31sec (451 seconds)

Published: Tue May 25 2021