The Solar Economy

talk about solar power and the solar economy. It was a subject that I researched to do a video episode Forward Thinking that that published previously, and we kind of wanted to to take the opportunity to go into a little more detail about solar power because we've touched on it in some previous episodes, but we haven't really dedicated a full episode to solar power. We we we've talked about related stuff though, so we're going to really concentrate

on it um. One of the reasons this is even coming up is that recently, relatively recently, Bill and Melinda Gates released their annual letter. And this is a letter that they publish publicly. It's like an open letters, pictures of their cats and say what all their grandkids are doing, like a Christmas letter, I hope you are well. This

year the Gates family saw something. No, it's not like that, it's it's really more about they like to tackle specific issues and address what they think needs to happen in order to solve problems around the world. And often these are really really big issues, things like access to clean water would be an example example. But and and this year, one of the topics that they covered was what was the importance of of getting our carbon emissions lower, like

to zero exactly if possible. The letters said, hey, look, according to all studies, carbon emissions are something we absolutely have to get control over. And if we don't uh this, this climate change is going to continue to escalate. Even if we were to get to zero right now, we would still see some escalation because it's not like it's an immediate uh fix. But if we don't do it, we're in real trouble. So we've got to find a

way to get to carbon zero. Yeah, they even or well a Bill specifically even took some time out of his very busy schedule to talk to our colleagues, Josh and Chuck of stuff you shouldn't know that episode, I believe published a couple a couple of weeks ago, late late February. UM, so if you guys don't already listen to stuff you should know, then go check out that episode. Yeah yeah, so I actually got to sit down and

interview him, which is pretty incredible. And as I mentioned, we've talked about solar power it kind of tangentially in several episodes on We published a podcast called is the power Wall a wonder uh? And that is related to solar power. The power wall being a type of rechargeable battery that one's marketed by Tesla and UH. It's designed to to store electricity when so that you can use

it when you when the surge prices are lowest. So for places like Hawaii and California, makes a lot of sense because you could rely upon solar panel energy throughout the day when the expense for electricity is high. You could rely on the battery at night, assuming you had enough charged up. But if you uh were using it in the daytime and you didn't have enough just from the solar panels themselves, you could use the battery and

then just use the grid when prices are lowest. Because the cost of electricity fluctuates pretty widely, and especially in California and Hawaii. Uh. Here in Georgie, it's not as big a deal. We talked about that in that episode, about how it all really depends upon where you live whether it makes economic sense. But we also chatted about solar power in an episode called can Artificial Photosynthesis Save

the Planet? That was also in May of two thousand fifteen video episode I believe, Yeah, I think that might have even been sort of what Bill Gates was touching on when he was talking about the stability of using sunlight to generate fuel. Artificial photosynthesis is one of the ways we could do that, either by creating a means of separating hydrogen from ox oxygen and water and that way we get pure hydrogen for a hydrogen based fuel, or even using artificial photosynthesis in a process to create

uh well, was essentially rubbing alcohol to use as a fuel. Um, yeah, tasty rubbing alcohol. Don't drink rubbing alcohol. No, it's not a bodily fuel. No. Yeah, he's just just used for for actual engines, not you. Uh. And then we also looked at the solar Impulse aircraft. We talked about flying

solar in April two thousand fourteen. That, of course is the uh the aircraft making its way around the world using solar power as its only means of generating electricity, you might add, slowly making its way around the world. It is a it is it is a gradual process. Um. But now are really going to tackle it? And in order to really talk about solar power, one of the most important things you have to address are the challenges

of solar power. Yeah, you might, without knowing anything about the subject, just assume, well, yeah, I mean, sunlight's free. Why don't we just why doesn't everybody have solar panels on everything? Put it on them? Coated with him? Right now? Yeah, I mean, why why why don't we just instantly convert to this? Seems like a no brainer. Put them on your house, put them on your cat. Just just go for it, right, A solar powered could he get? Actually,

that's kind of true. They like to find that little space. But they're also powered by the warmth of your laptop and also just by sheer hate. I guess what cats really thrive off of the inside themselves? They don't. They don't like it if you hate them. If only we could power our grid with hate, that would be excellent energy surplus for days. All right, So let's talk about some of the challenges are are related to solar power,

because why don't you put solar panels on everything? Yeah, we we we have to say this so that we can actually make a uh, you know, an informed decision further down the line about whether or not it makes sense in our individual cases. So one of the big issues for a very long time and still to some extent today is just the cost. It's they're expensive, right, So the sunlight is free, but the device you used

to harvest the sunlight is not. Right. And it's not just the cost of materials, although that's a large part of it. For one thing, solar panels usually have a fair share of rare earth minerals as part of the process of generating these solar panels, and right now we get those from China. There are there present in other parts of the world, but China uh minds them at an incredibly low rate because well, an incredibly low cost.

A high rate on the low cost, and the low cost is because they do so uh with extreme disregard for the safety and comfort of all of the people involved and also nearby, yes, very well. Put yeah, um, and apparently that ends up being uh. I mean, it's an issue in certain parts of the world where people have brought that up and said, we really seriously have to uh examine this, especially as we start to see more and more of those materials used in the technology

we rely upon day after day. But it's still pretty much the status quo. Sure, sure, yeah, and and researchers are to be clear making headway into finding alternate materials or or making less stuff work more efficiently, right right.

So so there's that, But beyond the cost of the materials, there's also the cost of installation, which can be expensive depending upon where you are and who you know, what sort of contractor you get to do it, And it's not something that the general you know, do it yourself, is necessarily going to be comfortable with. I'm sure there are people who installed their own solar panels and they're

perfectly confident and competent at doing such. I would be terrified that I would mess things up, and so I would end up hiring somebody who knows what they're doing. Uh. I would not rely upon my own abilities. So there's that. There's also the cost of maintenance, typically solar panels tend to the quote you usually here is that they have

an expected lifespan of about twenty years. So even if you are maintaining them properly and making sure that they're not suffering due to exposure to the elements and other things,

after twenty years, you're gonna have to replace them. So ultimately, when you start looking at all of these elements, you also have to think about, all right, how much money would I spend in that twenty years span, let's say, on electricity if I were to rely solely upon the power grid, assuming that the prices UH throughout that twenty year period remain relatively stable. And you figure that up and you say, all right, here's how much I would

spend in that twenty year period. Okay, how much would it cost me to get enough solar panels to provide the electricity I need for my house? Uh, knowing that in twenty years I would have to replace them, And if that amount is lower than the amount you would spend on electricity, otherwise you could say, all right, at least on this level, economically, solar panels would make sense. But of course, for a lot of people it's not just a cost saving feature. There are reasons to adopt

solar panels. Yeah, there there's the you know, the very strong argument of I want a more environmentally friendly approach to generating electricity. I want to be independent of the power grid. If something were to happen to the power grid. I want my house to still be capable of of generating electricity when the zombies are out on the porch. I want to be able to watch the NFL, right, or The Walking Dead and then at that point is

just a documentary series. Right, So that would be, uh, some of the examples that I think people would cite for their reasons beyond just the economic factor. Right. I think a lot of people who are early adopters of solar panels did so because they saw it as a more green option and also this idea of independence from from a larger system that if it were to go down for whatever reason, they would no longer be vulnerable to that same problem. So we've got that to keep

in mind as well. Now cost is just one of those challenges, right. Uh. We we also have the problem of efficiency now with solar panels. When we're talking about efficiency, you're not necessarily talking about all right, how much electricity does a solar panel generate. It's really about how much of the solar energy hitting that panel actually gets converted into electricity. That's what we talk about with efficiency. So there's a basic amount of solar radiation energy that's falling

on the Earth at any given time. Now you have some external reasons for that. Some would be like, uh, you know, weather like cloud cover and things like that. But then also you have internal reasons to the solar panels themselves that they can't get of that energy turned into electricity. Yeah, I mean, even under ideal conditions, a solar panel cannot convert all of the energy that's hitting it into electricity. And that's really what we're getting at here.

And like you, any solar panel, no matter how efficient, is obviously going to generate less electricity. On a day where there's you know, partly cloudy skies, it's going to have you know, it'll be less effective. It will be not effective at all at night. Simple simple thing there. But even with the most efficient solar panels possible, even theoretically possible, you can't convert all of the solar energy into electricity. In fact, the theoretical limit is uh, eight

six percent efficiency. Now, six percent efficiency is incredibly high, especially compared to what we see with solar panels right now. Oh yeah, and especially out of the lab. That's that's basically not not a possibility, right. Uh. When I say theoretical, I really do mean theoretical, as in, it is not a possible thing to do in reality. Why not, because you would require an infinite number of layers of solar panels in order to make this happen. Well, let's just

get working on them. How close we are too infinite? I think we're eleven off. It's not like that uh so soo of these theoretical solar panels, the energy hitting them would be lost and not be converted. But again, you can never build it in the first place. It's it's something that the math works out that is physically the the best you could ever expect under unrealistically ideal circumstances.

And that's just because of the of the mere process of converting uh photons into usable energy, like some of that gets lost. Yeah, and the fact that that you can't have a uh perfectly non reflective solar panel, so some of that light's going to bounce off with with an infinitely large surface area. Yeah, it's just strangely enough, whenever the word infinite comes up, it really gets beyond our capacity to make it. Okay, well, so we can't get up to eighty six percent efficiency, how what percent

efficiency can we get today? So average consumer panels tend to hover between eleven and fifteen percent efficiency, significantly lower than in other words, so because of that. Now, again this doesn't necessarily this doesn't relate directly to uh, the amount of electricity produced. This is again how much of

the Sun's energy gets converted into electricity. But that does mean that in order for you to generate enough electricity for your home, you may need lots of surface area to generate that electricity, because each individual solar panel is only going to be eleven to fifteen percent efficient under good circumstances like you know, direct sunlight as opposed to again a cloudy day or something along those lines. Um, a typical solar panel will produce around two d wats

of electric city. Keep in mind that solar panels are made up of lots and lots of solar cells. So you have tons of solar cells that are in an array together that make up a solar panel. Uh. So one solar panel would produce about twos of electricity, So to produce five kilowatt hours of electricity, you would need twenty five of these panels. Uh. And that of course

assumes that you are getting good solar exposure in that area. Obviously, if you live in a place where there are a lot of tall trees that cast shadows throughout part of the day, that's going to affect the amount of electricity you can generate through solar panels. So we might suggest if that's the case, that's probably not where you should put your solar panels, right, But if you don't have the choice, I mean, like it's the roof of your

house is sometimes shaded. Uh, you know, you might have to just you may have to come to the conclusion of solar panels just aren't a reliable option. I've got a solution to our world carbon problems. We can just cut down all the trees on the planet so they would never block any of the solar panels. Okay, So I'm going to move on without acknowledging that. Now. Obviously, another challenge we've alluded to it is that you're dependent upon when the sun is out in order to generate electricity.

These panels do not generate electricity unless they're solar energy hitting the panels, So anytime it doesn't, it doesn't hang out in the panel. There's not there's not like a lag time where electricity is still coming up. So if it's nighttime or if there's a sufficient cloud cover that there's not enough solar energy hitting the panels, you're not

generating electricity at that point. And electricity is a use it, store it, or lose it kind of thing, right, So this is true with any type of electricity generation, like your big coal power plants. You only you only want to generate as much electricity as there is demand, because you can't do anything with the excess and unless you put it into batteries, which we don't, right, So are our current power grid structure is based solely upon demand.

When the demand increases, production increases. When the demand goes down, production goes down. Otherwise you'd be wasting resources generating electricity that no one is using. So same thing is true with solar panels. If you don't use it immediately, then you have to have a way to store it or

else you're you're just losing. Now, this is where one of the previous topics we've talked about in this subject area came in when we did the podcast about the power wall, the Tesla power Wall, which is this proposed product that would be a home storage system for your own energy independence. Right, So this would be an important part of anyone's strategy if they wanted to switch to solar power. Uh, you're not necessarily the power wall, but

some system like it, right, the power wall. I think what the power wall managed to really do, which was really important, is it started to usher in a more affordable class of rechargeable batteries for home use, for for that kind of thing. Because batteries are also made with some rare elements that are are not rare elements rather, I mean that's not that they're rare in the ground, they're just difficult to get ahold of um and uh and and yeah. That makes them very expensive and can

be very carbon footprint heavy to uh to produce. Yeah. Now, with Tesla creating their Gigga factory where they're producing tons of batteries, literally tons of batteries when it's finished, Uh, that could mean that we'll see these prices go down even more because of just the economy of scale, where you're able to ramp up manufacturing, increase efficiency in the

manufacturing process, and past the savings on to you. But the cool thing here is that if you look at the history of solar energy for the home, batteries were some of the most expensive elements in those in those conversion kits. So some people might have said, while I'll use solar panels, but I'm just going to use the solar panels to provide electricity during daylight hours. At night, I'll rely on the power grid, or on cloudy days, I'll rely on the power grid because I can't afford

to install the battery system that will allow me true independence. Yeah, and and this. You know, batteries can certainly help, but the sheer sun factor can make it really not worthwhile to install solar panels in certain geographic areas, not even if your personal house doesn't it has too much tree cover or something like that. But you know, it's the kind of thing that works really great if you live in like l a or the desert, like the kind of place where if someone sees a rain drop that

like Instagram and immediately um. But but it works less well if you live in like Seattle or London or something. I think if you're in a subterranean cavern, yes, yes, it works less well for gallum or then perhaps Yeah the Morlocks. Yeah, there's a whole there's a whole population that we're not serving here, but there are the Morlocks. Are the Warlocks really concerned with with with their carbon footprint? They are? But the Morlocks use geothermal energy. Good on you, Morlocks.

So at any rate, boy, I gotta just keep on top of this cat. Uh. So anyway, let's say that you are at home and you're considering switching over to solar power. How do you know if it's actually a a an intelligent choice for you to make. Let's I mean,

environmental concerns are definitely a big part of it. And if you have enough money where you are comfortable investing in something that may or may not pay off in the long run, depending upon your own situation, I applaud you for moving off of a system that relies heavily on fossil fuels. But not everyone has that luxury, right, Not everyone has enough money where they can arbitrally make

that decision. They might have enough where they can say if in twenty years I will have saved money over that course of time, then I can afford to do this. That's a different story. Sure, sure, it's It's like when we were in the early stages of electric electric and hybrid cars in this country, where it was a it was an environmental choice that you were making, not a not a personal savings choice. Definitely an early adopter person with a lot of a lot of capital to be

able to spend on that sort of thing, big green heart. Yeah, yeah, which again I mean that those are the people that we depend upon in order to bring these technologies to a point where the rest of us can afford them. So questions you have to answer, does your home get enough solar exposure not just with the the shadows like the tall trees or whatever, or or how much cloud

cover do you get on average per year? But you know, the further away you are from the equator, the more time your home is going to have exposure to non sunlight hours. Right, So like if you're really way up there in Alaska, there's gonna be some stretches of time where you're not going to get very much sunlight at all. And during that time, of year, you will not be able to rely solely upon solar power to generate the

electricity you need. Uh So, fortunately you don't have to spend much energy on air conditioning that you would think so. But the one time I visited Alaska, they were having a record breaking heat wave and everyone was going crazy because no one could sleep. So, boy, they were some I mean, I don't know how you Alaskans are normally, but you were a little ornery when I visited at

any rate. Uh So, other questions you should ask, does does your area offer tax incentives or rebates for switching to solar because a lot of places do have these incentives in place, and if you can take advantage of that, that removes some of that upfront cost for the purchase and installation of solar panel systems. So that's an important question to ask. Also, how much does electricity cost in your area? Yeah, you mentioned this cost different things in

different places. So in Georgia, again, it's one of those things where if you switch to solar power, it may be more of an altruistic approach because generally speaking, our electricity rates are pretty low in the state compared to

other places in the United States. Uh. So, then you can gure out how many years will it take for you to pay off your solar power panels based upon the savings you make and electricity use, and as long as that number is less than what it would take for you before you have to replace them, it may be a good choice. And if this sounds like it's all a lot of math and difficult number looking up that you might not have, you know, at access to that kind of of data. There are companies that are

trying to our projects, that are trying to make it easier. Yeah, And one of the ones that I think is super cool is actually a spinoff company that started as a project at m I T and it's called map Dwell. So map Dwell what they want to do is create solar powered communities where you actually have neighborhoods that rely on solar power and that can support one another. So in other words, you have your own kind of mini solar powered power grid that's neighborhood based as opposed to

UH city based or whatever. So they've started developing a tool called solar System that is designed to help people figure out if solar power would make sense for their personal home or in some case like a building owner whether or not it makes sense to put solar panels on the top of the building. And they add a really interesting way of going about this. First they sent out aircraft equipped with lidar, which is essentially a laser

version of radar. And the basically what does is it it fires down a laser and looks for the reflection to bounce back as a sensor that that collects that data and by measuring those minute changes, it can create the topography for an area. Can it can accurately map the topography, And so they get those measurements back for all the tops of buildings in an urban area, and that starts the basis of the three D model they create.

After that, they end up combining that with data from other sources like geographical sources and weather sources to determine how much sun a particular rooftop would get in an average here. So they go with that and then they start plotting dots on the rooftops showing where what areas

of the rooftops get the most sun exposure. So that way, if you were to invest in solar panels, it would show you where you should concentrate those solar panels, not just you know, don't just put them on your roof. This is exactly where on your roofs you should put them. It's pretty cool idea. Uh. And then the dots are color coded to let you know how suitable that area

is for solar panels. By the by the way, all these dots when they're combined, it just looks like gradations of color, but essentially yellow, very bright yellow indicates this is primo landscape for solar panels. And then it starts to go from yellow to orange to brown. When you get to brown, it's like, this is probably not a good place to put your solar panels because you're not

gonna get enough solar exposure for it to be worthwhile. Now, if you want to take a look at, uh, installing solar panels on your own home, assuming that apped Well has actually mapped out your home. They've only got eight cities in the US mapped out as of the recording of this podcast, but they're hoping to have all major urban areas in the United States mapped out before the

end of twenty six UM. If you wanted to check out your own home, you could either highlight areas of the map where you want your solar panels to go on your actual on the roof of your house, or you could use an automated function which would then plot what the algorithm has determined are the the best spots for your solar panels. Yeah, and and it will also look into other regional data for you, like like whether or not there are any tax breaks that you can

take into consideration. Yeah, all those little factors that I mentioned earlier, mapp Dwell has decided to include that information so that you can see how much expense you would be burdened with upfront, how how long it would take you to pay off the panel investment um, and other information like that. So, in other words, they collected all those little bits and pieces we talked about earlier for you on your behalf. So it makes it much easier for you to see if it makes financial sense for

you to switch. If you're like well, according to this, in seven years, these solar panels are going to pay for themselves. And that's just assuming that the prices price for electricity remains constant during that time period. I'm comfortable making an investment. I'm going to stay in this house at least seven more years. Or maybe you're thinking, I'm gonna sell this house before that, but this is going to add to the value of my home. Either way,

that could guide your decision going down this path. But if it says something like eighteen years, you're like, well, then I get essentially two years of use of this, where I am I've paid everything off essentially before I have to do it again. That might not make sense for you, and you may choose not to do it, but so useful tools so you can quickly assess the

suitability of your your rooftop for solar panels. And if you could create these communities, then you again would have like at least many power grids, so if if you need to, you might be generating more electricity than what you require for your home, so you could actually uh use that electricity to help some of your neighbors in case they have greater requirements at that time. So, since you've all made the investment for the solar panels in the first place, it's not like anyone is losing money

on this. Although I guess you could even create an economy based on this if you really wanted to, I think that would require a lot more thought to go into it with meters and everything to figure out, all right, who generated the electricity I used to dry my clothes this morning. I owe you a coke. But it is it is the possibility of a solar economy. That's this idea of we actually can harness the Sun's power, not just for our own electricity needs, but actually to make money,

um through these the smaller community based solar networks. Although you can already do that in some to some extent in some areas by selling any excess electricity back to the power grid. Um. That that's not true everywhere, but in some places that is allowed. So that's another possibility. All right, that's really cool. But let's say that we want to think bigger than this, bigger than someone's own

personal property. Uh, and using solar panels there, What if we wanted to create a solar farm that could generate enough electricity to supply a thousand houses are more with electricity? And of course we all we already do have solar farms out there, but they're not as efficient as we would like them to be. For one thing, they are they're still reliant upon the sun being out. So even if you put them out in the desert where they're going to get great solar exposure through the entire year.

Once it's nighttime, you're not generating any more electricity from your traditional solar farm because you have to have that sunlight to hit the pan als to generate the electricity. But what if you harnessed electricity from the sun in a different way, using heat rather than the sunlight as the basis for the electricity generation. And that's the idea of the solar tower. So I've heard this explained. Is solar thermal or thermal solar? Yeah, yeah, thermal being heat.

It's exactly the way this works. I specifically concentrated on a US company called Solar Reserve because they've built a solar tower as a as a sort of proof of concept to show how this thing would work. But basically, the way it works is that you can you can generate electricity day or night because you're storing heat and

using that heat to do work. In this case, the work is the same you would see with a lot of other types of solar or rather electricity generators, which is you take our good friend h two oh, you turn it into steam. That steam under pressure moves the turbine the turbine generates electricity. Uh. Now normally we use like coal fired plants, oil based plants, uh, nuclear reactions. Yeah, these are all different ways that we use to heat water up to a really high temperature, so it creates

steam and then turns turbines. So this is a similar thing, except instead of using fossil fuels reusing or nuclear fuel, we're using solar radiation. I guess technically we're using nuclear fuel. It's just nuclear fuel. That's the Sun. So it's really through the radiation of its energy that we're we're harnessing this because as we all know, the sun is a mass incandescent gas. Yeah, gigantic nuclear furnace. UM. So the

solar reserve. The way that the way they've designed theirs is they've got a tower that's in the middle of kind of a field of mirrors, essentially, and their tower is six ft tall, which is about and at the very top of it they have what they all the receiver. This is a series of panels. They use fourteen panels um and in groups of seven, and each panel consists

of sixty six thin wall straight tubes. So essentially you can think of it as as these areas where it can trap heat and and conduct the heat from the outside to the inside of the tower. And they're coated with special material to be as uh uh to to raise the absorptivity so that you make them they absorbed so much of that heat they're very little of it gets lost. So all those mirrors are pointing light up

to the top of the tower. These panels are designed to absorb heat at high efficiency and transfer that heat to the inside. And on the inside you have pipes, and inside the pipes are is liquid salt. So you've got liquid salts circulating through the pipes, and the pipes kind of go through a heat ext change and it's not that different from the sort of stuff you would see in like a refrigerator um or or an air conditioner. So it's imagine this pipe making kind of a a

criss cross pattern across seven of those fourteen panels. They have two different pathways, one for each group of seven. And as the pipes pass along these panels, on the inside, they're absorbing the heat that's coming from the sun and that's starting to turn the liquid salts molten, so super high temperature here really pretty steamy stuff. We're talking that they keep it. Like the low level for the molten salts is five fifty degrees fahrenheit, which is two degree celsius.

The high level is a thousand fifty degrees fahrenheit or five sixty six degrees celsius. Yeah, that's warm, and it according to them, like the way once it's heated to the right temperature, they put it in a storage tank. According to them, they only lose about a degree of fahrenheit of temperature per day in that search. Yeah, you just leave it there, and that's why they can generate electricity. Chemistry. I love it. It's pretty really excited about the melting

point of salt. So fascinating. Well, and it's it's it's really interesting because again you can generate electricity day or night because you're not relying upon the sunlight. You're relying upon that heat that's been stored and use that those molten salts. You can pass it through another heat exchange which then passes the heat from the salts into water. Keeping mind the salts and water don't make contact with

each other. It's essentially that you have another series of pipes that go through a huge tank of water converts that water into steam, steam turns a turbine, the steam goes through a condenser, turns back into water, and the salts that had been used to heat that water then go into a separate tank to be pumped back up

to the tower to be reheated on the next day. Yeah, most of the time, the actual substance that you're making warm is it's not the substance that touches the water literally, right, Uh see see above recal plants, Like, you're not dropping hot coals into waters, and you're not not dropping hot nuclear rods directly into water on purpose anyway. Yes, that has happened accidentally. It's considered bad when that happens. So

we're talking about a pretty big operation. Even for the solar Reserve proof of concept, they have ten thousand mirrors covering a fifteen hundred acre field, so you need a lot of surface area for this um and uh, you know, when you're talking about the liquid salts there, they say that five thousand, eight hundred gallons of liquid salts passed through the receiver circuits every minute, So lots of power

going on there. The nice thing is they can use their own electricity to power the pumps right, They don't have to pull power from somewhere else in order to do that. So once it's primed and ready to go, you've got a self sufficient system. Now, according to Solar Serve, each plant would have a an expected lifespan of thirty years.

So again you have to look at the amount of electricity it will generate in that thirty year span and determine whether or not that makes financial sense to support that kind of system as opposed to again relying on more traditional methods of generating electricity. UH. And as for how much electricity you can generate, well, depending upon the size of the plant, it can generate between fifty and

two hundred megawatts of electricity. One megawatt is enough to power uh one thousand homes more or less, so between fifty thousand to two hundred thousand homes could be powered by one of these types of solar towers. Now, when you think about the average city size, obviously you're going to need more than just one of the size in order to power it. But it's a good way to offset some of the electricity needs for a community. Um,

it's really a city. And so UH they say that they've got one point eight billion dollars worth of contracts active worldwide right now, and they hope to continue to expand in the future, so much so that they retweeted me yeah, because they saw that the that I did the video about them, and so they said, hey, there's actually I didn't retweet, they mentioned me and say, hey, there's a great forward thinking video that you should watch

because they totally talk about us. But I think it is a really cool idea and an interesting way to work around that limitation of your only generating electricity when the sun is out. Yeah. And and furthermore, just upsetting those those materials that can get that can that can get so expensive in multiple ways for solar panels, yes,

uh so uh. And then they're very careful to explain that the way they generate electricity is fundamentally different from a solar panels approach, but that they both ultimately rely on the sun for the source of energy. It's just they go about generating electricity in very different ways. Before we move on, though, I do want to correct my prior lyric statement because I believe they might be giants. Has has changed the song now to a miasma of

incandescent plasma. That is correct. They did go back to to UH because so many people were writing in to say, you know, your song is really gas not so accurate. And to be fair, that song was a cover that came from an educational album because I owned the vinyl album that came from. And Schoolhouse Rock is not schoolhouse Rock but the original, the original, the original version. The guy who sings it sounds like this. The song is a mass of incandescent guess a gigantic nuclear furness. Are

you gonna keep singing? No? But that's that's he hits those ers real hard. This is what's so charming about it. Anyway. UH. Let's talk a little bit about the future solar panels. So we've already mentioned about the the peak level of efficiency that's theoretically possible and that will never hit that right where even when we see the ideal solar panels being used in UH in labs right now, with perfect conditions, you don't get significantly higher than what we're seeing UH.

In the field. I mean, you hear about forty. Sometimes you'll hear even as high as fifty. But that's like real pie in the sky conditions, like in a laboratory controlled with like such expensive equipment. And then yeah, and and perfect solar exposure, Like there's essentially every single part of the panel is being exposed to the perfect light. Yeah, so it's it's something that would never happen in any practical sense. But that doesn't mean that we're stuck with

the status quo forever. I mean, efficiency might be a very limiting factor and only very slowly increase over time, But there are other ways that we can see solar panels changing in the future. And a big part of that is the expense of solar panels. Oh yeah, and so many researchers are working on so many different aspects of this problem. A few things that have been in

the news recently. M I T announced to prove of concept material that's so thin and so light that you can put a panel of it on top of a soap bubble and it will work without bursting the bubble. And I mean, of course, this is not what We're not trying to put all of our new solar panels on soap bubbles. That wouldn't really be the best choice, I don't think, for multiple reasons. It could be a really energetic foam party. Though, why don't we keep talking

about foam parties on the show. It's been a it's been a while, okay, but uh, but yeah, so one of the problems of solar panels is that the weight of them restricts how you can install them and where you can install them. And traditional cells that use glass, uh produced some like fifteen watts of power per kilogram of weight, and these cells output more like more like six watts per gram, which is like a four hundred times improvement. That's not shabby. UM, They're they're they're working

though on making the manufacturing process scalable. Right now it's you know, enormously expensive because they just invented it. The process that is really interesting to UM. All the layers of the cell can be grown simultaneously in a single vacuum chamber. By growing, I mean deposited through fun physics

that I don't understand extremely well. But but but yeah, so if they work at the scaling thing, the material could be used in places where we've where we've had trouble installing solar panels, like on on weather balloons and Internet balloons in the case of like Google Loon project and stuff like that. UM, or even like personal items like clothing or bags. I bet that would be a much better solar panel system than that back pack I used to have. Oh yeah, yeah, I have a solar

panel embedded in it. I remember when I got that one. It was really heavy because it was not one of these types of solar cells. And for another, it was not terribly practical because you would read that in order to recharge your device, you would need to have the backpack placed in direct sunlight for twelve hours. How how long are days here in Georgia's well, even on a twelve hour long day, I can't imagine ever being like, well, hang on, I gotta go move my backpack again. Attached

the backpack to the cat. The cat will auto find the best sunlight. Yeah, I did that, but the cat wasn't able to move very much. Should have unloaded the backpack. First lessons for the future, Yeah yeah. There's other research UM some some out of Washington State University and the University of Tennessee, which we're collaborating with the U s

S National Renewable Energy Laboratory. UM are are working on a manufacturing process to improve one type of solar cells called cadmium teleide cells, and in comparison to silicon cells, they perform a lot better in a lot of real world scenarios, like like if you've got low light and high humidity in an area, but but they've been less efficient overall. Um that that scent I believe refers to silicon cells, not to not to other types of cells, which in silicon are the gold standard for the best

possible efficiency right now. Um other types of cells just had like a poor life expectancy in general. But this new process improves the conductivity and the carrier lifetime of cadmium teleide materials and and could eventually challenge silicon cells

like hold on the commercial market. That would be a great uh thing to something that could have that big of a potential impact, and especially with elements that are a little bit less difficult to deal with than silicon, that that are less expensive to mine and less polluting to the environment to to purify um. Speaking of which, advances in recycling are another another concept that people are

working with. There's research out of the Technical University of Denmark that's improving the process of breaking down old solar cells to reclaim all of these expensive materials, which will hopefully, like a prevent those materials from damaging the environment and landfills and be help offset the cost of obtaining more

of them. The process involves burning old cells instead of using chemical baths, and the heat energy given off could even be cycled back into the processing plant to help power itself, so you get some thermal energy from just

the process of recycling these solar cells. That's a great idea because, like we said, with the average lifespan being around twenty years, knowing that you're going to have to replace these at some point because that efficiency we talked about over the lifetime of the solar cell that's going to decline as well, is just going to become less efficient over time. Just as all all systems must obey entropy,

eventually things breakdown. So having a system of recycling to help offset what we would need to create a new batch of solar cells as well as making very clever use of that excess heat. I like that idea a lot. I hope that we see that. First of all, I hope we see that it's truly successful, and secondly, I hope that we can see it adopted by by more nations.

In the future. Now, do you think we're ever going to reach a time when all of our energy needs could be met by solar No, not directly right now, because well, there are a couple of different things to consider. I mean, one of them is the abundance of solar energy,

which truly is quite abundant. I mean, we were able somehow to harvest all of the solar energy that fell on the surface of the Earth, I think that would be more than enough to do all the stuff we need to do, But that would also be a kardachief of one SI stations. We are nowhere near that yet, right, Yeah, so we for pretty obvious reasons, we can't do that. Yeah, lots of lots of very good reasons, Like we can't cover the entire surface of the planet in solar panels

or mirrors. We can't cut the entire surface of the Sun in solar panels or mirrors. Yeah, if we did that, we'd go we'd be jumping ahead to yeah, which would be awesome. But yeah, we cannot build our our dicen sphere yet. So um, yeah, it's it. I don't think we're going to see a time where solar energy will provide our electricity needs. But I certainly think it could heavily offset our needs, and that with other renewable sources

we could perhaps make up the difference. So everything from geothermal to hydro power, to wind power, uh, that sort of stuff. I think Jor on a bicycle, yes, never let him off that bike. I think. I think with the combination of these it could be possible for us

to meet of all of our electricity needs. The question is does it make First of all, does it make enough of an environmental impact to warrant that change, because as we pointed out, a lot of these technologies require us to do other work that emits that you know, has pretty significant carbon emissions. It's just they're on the there on a different side of the uh, the energy equation than where you would think of on a something like liquid fuel. Right, the burning of liquid fuel creates

carbon emissions. Obviously sunlight doesn't create carbon emissions, but the production of the technology that allows you to harness the sunlight does. So you have to look at that. You have to look at the economic side of it, obviously, because it's very hard, I think, to lead to lay down the argument, hey, stop using fossil fuels which are cheap and plentiful to you right now, and start using this technology which is relatively expensive to you right now,

because we don't want you ruining the planet. It's hard to say that, especially to nations that are are just catching up to where a lot of other countries were fifty years ago. You know, it's very difficult to make that argument in a way that doesn't come across as

purely hypocritical. Um. But I think it's really nice that the tools we mentioned with mapped well, and there are other sources out there as well, can let people make their own personal decisions as to whether or not it makes sense to at least look into solar panels as a way to offset their own electricity needs, possibly meet all of their needs. Uh. I would love the idea. I mean, I love the idea of of doing that at my house. UM. I don't know that I could do it. I'd have to look at the h o

A agreement. But I would love the thought of being able to do that at my house, again, partially as a way of being independent of a larger power it should things go terribly wrong for whatever reason, or if another transformer just blows because I had one of those. Happened over the weekend. Yeah, just exploded over you were you at home by yourself with no power? I was not by myself, I know, that was before before my wife left on her trip. I was, but she was

asleep and did not wake up. But yeah, I was. I was actually on my computer and then I heard a distant popping noise and then all the power went out. So it was not a transformer that was close to my house. But still that sort of thing does happen, and it would be nice to be independent of all that. At any rate, this was kind of It was kind of fun to to really dive into this topic since we hadn't really spent a huge amount of time on

it directly before. So, guys, if you have any questions about solar power, or you have any other topics that you would like us to tackle in the future. You want to know what the future of whatever is right us unless no our email addresses f W thinking at how Stuff Works dot com, or you can drop us a line on Twitter or Facebook. We are fter you thinking on Twitter search f you thinking on Facebook, We'll pop right up. You can leave us a message there

and we will talk to you again. Really. For more on this topic in the future of technology, I'll visit forward thinking dot Com, brought to you by Toyota. Let's Go Places,