The Cost of Sunshine

solar power looks amazing you take a piece of silicon put a little stuff on it connect some wires to it and free electricity comes out whenever the Sun shines well it's it really free in all things about energy economics comes into play if I can make my electricity cheaper one way versus another an average I'm gonna make it the cheaper way so let's look at the economics and to do that the first thing we should ask is how good are these things at capturing the sunlight the first solar cell I told you about it wasn't very good just rubbing some phosphorus on a piece of silicon not gonna give you very high efficiency efficiency is defined as the amount of energy from the Sun in vs. the amount of energy from the electricity out very logical number let me show you a graph of efficiency over time so we've got dates on the bottom and this goes all the way out to to the latest data from when we were filming this in late 2015 and on the side is the efficiency and you can see the very very best cells are over 40 percent 44% efficient that's amazing of a hundred photons coming in or one hundred units of energy coming in forty four of those units of energy returned to electricity now these world record cells have multiple layers multiple junctions and they cost a lot if you're building a space shuttle or an International Space Station that's what you want if you want to just get inexpensive solar PV on your roof that's not what you want we can look here in the mid levels there are single crystal silicon cells and we're in the 20s a percent that's pretty good and then you have a whole bunch of new technologies places that don't have to start with an actual single crystal ingot of silicon but can make this in modern film deposition techniques and there's a variety of them there's some very exciting that are having a very rapid rise this is awesome because these promise the ability to do it cheaper and to do it on a more mass-produce scale in the end this doesn't tell you dollars this just tells you how much area you need to get a certain amount of wattage still though if you could make a sell for the same price at a high efficiency versus a low efficiency clearly you're going to be able to buy it for less money the real key here beyond efficiency when you look at economics is the concept of dollars per peak watt all the efficiency is taken into this graph because I don't care how big the cell was I'm selling it to you per watt well not exactly per watt per peak what if I have the brightest possible sunshine on the planet shining on it at noon with no clouds this is how many watts I could get out and this is a remarkable graph because we've gone from 25 years ago at six dollars to today to under $1 for Pequot tremendous variation of this for a long time before this in the 80s it was stuck at this number and then it really looked like it was going to be stuck at 3 dollars and then more innovations in manufacturing have pushed this dramatically lower especially with the rise of Chinese massive solar PV investment into the factories that make it out of single crystal silicon still though this is price per peak watt and we don't buy electricity that way we pay dollars or some type of currency per kilowatt hour or per Joule right we pay per the energy produced not the energy it could hypothetically produce on a bright sunny day how do I convert these let's do a little math okay dollars per peak watt and we can multiply in the end let's just start out by saying I could buy those cells for $1 per Pequot there's one other thing I have to ask how long is this cell going to last am I gonna put it on my roof and next month it'll be broken it'll be garbage it'll have worn out sort of like a battery in which case it's not a very good investment or will it last on my roof forever well forevers a long time to figure out how long it really lasts you probably should ask the manufacturer how long are they going to guarantee this how long is my warranty how long then if it breaks because of a manufacturer's fault you'll give me a new panel and these days this is for about 20 years we're gonna need that data now there could be natural disasters hailstorm your house could burn down right that'll break it a lot sooner but that would make a lot of things a lot sooner so let's take this dollar for Pequot that'll last for 20 years and let's try to convert it in the end into the way we buy electricity in the US dollars per kilowatt hour a watt second is a Joule so this is some number of joules how do we get from here to there first thing we have to do is we need to convert this Pequot one peak walk to an average watt a plain old normal hey can I make electricity out of this and this number right here depends on your location if you live in a sunny desert this number might be 0.4 if I live here in Illinois its 0.2 only 1/5 of the time is the sunlight super bright and shining straight down well actually you all know the Sun is gonna be totally gone at night and then it's gonna rise and it'll be some peak and we'll be gone but if I average this over my whole 24 hours whereas maybe this is the number that should come across here at 1:00 and I average this all whole thing together right I get 1/5 of that 0.2 so counting day and night variation and counting how many clouds come into the city on an annual basis I can get this number from my location I'll do the one for here in champaign-urbana okay that's great I've gotten rid of pequots now I got plain old watts I want kilowatts well that one's pretty easy right so there's 1,000 watts per kilowatt okay got kilowatts on the bottom watts cancel but this time I need here this hours and how do I utilize the fact this is gonna last for 20 years well we've got time on the bottom in years so we just have to know that one year is 8760 hours years will cancel out what I'm left with is dollars per kilowatt hour if I multiply these numbers together including the 20 down here this comes out to be two point eight five cents per kilowatt hour little under three cents per kilowatt hour if my solar cell cost $1 per Pequot seems very very good almost too good to believe this is about the price that centralized coal power station can make electricity so why hasn't the whole world switch to solar well got a couple other considerations to think about one is that I'm really only making all this electricity during the daytime so if I want to switch to a complete solar system I have to store that energy I make to be available to use at other times a day like at night when you want to have lights and you still want to have your electronics working storage is expensive but still being able to run everything if it really only costs this much during the daytime would still be a tremendous boon well let's look at a couple other factors so one of those other factors is that location number remember I said that here in Illinois it's about point two here down in Arizona that number is about 0.4 in some places where you really wouldn't think of putting solar power like the Portland area where it's rains a lot that number would be more like point one this graph shows where you get the sunshine and therefore where it makes much more economic sense to put in a PV system you can take that data the amount of sunshine and you can also take into account the price of electricity from alternate sources and this is really a fascinating graph because each of these lines like this represents the price at a solar panel at which it makes economic sense for that location something here in Honolulu Hawaii makes enormous amounts of sense because one their normal price of electricity I mean Hawaii is an island state it's a long way away from any fossil fuel you need to truck and ship there and then refine it that's a lot of money so their price of electricity is ver kilowatt hour is very high from conventional sources their amount of total solar insulation the amount of sunlight they get is extremely high absolutely makes sense to have solar panels in Hawaii we can go across here UCLA is very very sunny and the electricity is still pretty expensive Phoenix yes sunny all the time but you know their fossil fuel costs are also pretty low then you get into maybe the less likely areas I mentioned Portland Fargo North Dakota not a lot of Sun but very cheap fossil fuels notice that this graph has a suppressed zero zero is where they down here so it's not twice as expensive from here to here but if you then think about this graph and you think about what we just calculated as the price per Pequod's it looks like it makes sense to do solar power everywhere but what I gave you before was the price per peak want at the manufacturer not the price of installed capacity and the economic numbers really need to take into account the actual amount of money you spent to get those panels in operation this is an average price of installed solar power and while it only goes to 2013 I'll tell you the current numbers notice that this is up in the six to seven dollars per peak watch why are there three lines on here well the different lines are depending on how many solar panels you're putting in all at once clearly if you're putting in a much much bigger system you're gonna have a lower price per installed watt but even in 2013 here these prices were close to $2 yet our installation prices are still six and if I continue these lines down to 2015 it's still costing five dollars even for the largest system to install new solar capacity so let's go back a slide we're at the five dollar per watt install line this one la San Francisco Las Vegas Hawaii makes sense economically Fargo Seattle Salt Lake Denver don't at $5 per installed capacity so even though you can buy this stuff for under a dollar for Pequod's for the panel's you can't install it in the United States for less than five what's up with that well the thing is that the solar panel has to go on something so you've got to build the thing it goes on and you might say hey I already have a roof on my house just slap them up there well you can't quite slap them up there because your roof might not have been designed to have heavy solar panels on top of it and you have to get the wires and the electricity you make is direct current but the stuff you use is AC so there's a device called an inverter that you have to buy as well there are certainly some real costs but there's also some costs that definitely could be trimmed let's look at this graph this is a graph of the installed capacity price in Germany versus the US and you notice for many times this was very very similar than somewhere around the middle of the 2000s there's fantastic divergence and again this is a 2011 graph these numbers have continued in this trend has continued as well that the price to install it in Germany maybe is no longer half but it's definitely significantly less than the price to install in the US well this always floored me our labor costs don't seem to be dramatically different our standards of living don't seem to be dramatically different or both developed countries so I looked into this a bit more one of the biggest problems of why it cost so much in the United States to install solar panels even when you buy them cheap is regulation that regulation is born from lack of standardization in Germany you have much more uniform building code installation code and everyone's roof looks pretty much the same in the u.s. we have an enormous wide variety of building types of local municipalities local counties local states that provide different degrees of regulation and different degrees of paperwork that has to be filled out now I'm not saying paperwork's bad clearly you don't want people doing things that become an unsafe hazard to themselves or their community and I'm not exactly sure the right way to solve this but I definitely want to point out the issue because when you do have these levels of different types of installation that need to be done because everyone's roof is custom and different types of of regulations to be taking an account of in every different municipality city or state well then you're gonna need to actually pay the people who do it more the typical solar installing company has a lot of college graduates in the u.s. in Germany it's a trade and you can do the labor much cheaper you can do the installations much faster because each installation looks exactly alike the last insulation that company did I do hope over time that our install and cost will decrease but even if the solar panels are free there is still a cost because of you have to buy some structural stuff you've got to actually put it up and you actually have to convert the DC still though with prices of panels going down the economic availability of solar is certainly going to increase that's what you need to know about solar economics [Music]

Channel: Illinois EnergyProf

Views: 136,445

Rating: 4.9267821 out of 5

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Id: VKeiMWXUkCI

Length: 18min 5sec (1085 seconds)

Published: Mon May 13 2019