Solar technology for producing energy is a rapidly growing industry that harnesses the sun’s limitless power. This video and transcript share an innovation in new technology that is transforming the solar industry.

“Every 24 hours, enough sunlight touches the Earth to provide energy for the entire planet for 24 years.”

– Martha Maeda

“We have this handy fusion reactor in the sky called the sun; you don’t have to do anything, it just works. It shows up every day.”

– Elon Musk

In this video we’ll explore the world’s fastest-improving new solar technology and provide an exclusive peak inside the lab of a team working on this breakthrough material right now while you’re watching this video a giant fusion reactor 93 million miles away is irradiating the earth with about as much energy as all of the human civilization uses in a year.

Right now, while you’re watching this video, a  giant fusion reactor 93 million miles away is  irradiating the earth with about as much energy  as all of human civilization uses in a year. So why aren’t we harnessing this abundant, renewable energy source to meet  all of humanity’s energy needs?

It’s not an issue of physical impossibility,  “If you wanted to power the entire U.S. with solar panels, it would take a fairly  small corner of Nevada or Texas or Utah. You only need about 100 miles by 100 miles of  solar panels to power the entire United States” Currently, only 2% of global electricity  comes from solar power. And 90% of that, comes from crystalline silicon-based solar  panels, the dominant material technology.

While abundant, silicon has  downsides related to efficiency, manufacturing complexity, and pollution that  prevent it from being an absolute no brainer. Now what if I told you about  a material that was lighter, more efficient, and simpler  to produce at a lower cost?

An inexpensive solution that can  make a photovoltaic cell so thin, that just half a cup of liquid would be enough  to power a house? A solar panel so lightweight, that it can be balanced atop a soap bubble. Well, that folks, is known as the holy  grail of solar, They’re called Perovskites, and they might just revolutionize how  humans generate energy from sunlight .

We headed to silicon valley to meet  Joel Jean, the CEO of Swift Solar, one of the leading teams working to bring  Perovskite solar technology to light. It’s a new kind of thin film technology. So you’ve  probably heard of that for a long time, different kinds of thin films have come and gone over the  years. What we do here is a new kind of material. It’s called perovskites, a new semiconductor  material that absorbs light really effectively, also transports charge. So it just turns out  to be very efficient material for solar cells.

Solar cell technologies can be classified into  two categories, wafer-based or thin-film cells. Wafer-based cells are fabricated  on semiconducting wafers, and are usually protected by a material  like glass. These are the crystalline silicon cells you’ll typically find  on bulky roof mounted solar panels. Thin-film cells are made by depositing thin layers  of semiconducting films onto a glass, plastic, or metal substrate, and use 10 to 1000 times  less material than crystalline silicon cells.

These thin-film cells are light and flexible, but have lower average efficiencies. You can make thin film cells from  amorphous silicon, or more complex materials like Cadmium Telluride, but  scientists have been on the hunt for better thin-film solar technologies  that can see more widespread use. These materials are known as “emerging thin films” Currently, Perovskites are the leading contender.

What could you do with a  solar panel with 100 times the power-to-weight performance  of conventional silicon panels? A solar material so abundant, it  could be painted on skyscrapers. Flexible, lightweight, highly  efficient cells could open up a wide range of applications where traditional  silicon cells are too heavy and rigid. But before we cover your Tesla  model S plaid in perovskite solar, what exactly is this revolutionary crystal? The Perovskite crystal structure was  first discovered as the naturally occurring mineral calcium titanium oxide.

But the Perovskites used in solar cells  don’t need to be mined from the earth. A perovskite is any material with a crystal  structure following the formula ABX3. Where ‘A’ and ‘B’ are two positively  charged ions, often of different sizes, and X is a negatively charged ion. Scientists realized that they could create a  diverse range of man made perovskite crystals, following this same arrangement,  that have very useful properties.

So we use basic, you know, metal halide salts,  so things like lead iodide or some some organic salts as well. And we combine them  to make these inorganic organic, hybrid perovskites. So if you can form  them in solution, you can form them out of, in vacuum out of vapor phase. And they condense  into forming these perovskite crystals.

And the thin films, they’re like  multi-crystalline, which means that there’s a bunch of little crystal domains, they  turn out just to be really good semiconductors.

So just how efficient are perovskite solar cells? The most efficient modern silicon solar panels  you’d find on a home only work at best around 20% efficiency, but the theoretical conversion  efficiency of single junction solar technologies is about 33%, called the Shockley-Queisser limit. That’s the fundamental limit  for a single solar cell singles material based solar cell. Perovskites  are the exact same thing. Silicon, perovskites, cadmium telluride, CIGS, all  of these technologies have the same limit. But perovskite solar cells can be made  in a form factor that’s capable of much higher efficiency limits, pushing the  boundaries of possibility for solar power.

To understand why perovskites hold an  advantage over traditional silicon solar cells, let’s first do a basic refresh of how photovoltaic  cells convert sunlight to electricity. The top and bottom parts of a  solar cell contain semiconductor materials with different electrical properties.

In a traditional silicon cell for example,  silicon is used for both layers, but each layer is modified or “doped” with tiny amounts of different  elements to create different electrical charges.

The portion that contains a higher concentration  of free negatively-charged electrons is called the n-type region, and the side that  contains more positively charged holes, or missing electrons, is  known as the p-type region.

The boundary between these two layers is known  as the p-n junction. When an n-type and a p-type material are put in contact, free electrons from  the n-type material and free holes from the p-type material move across the boundary and cancel  each other out. The electrons fill in the holes.

This uncovers the fixed positive and negative  charges of the dopant ions, which creates a built-in electric field that stops more electrons  and holes from moving across the boundary. This electric field corresponds to a built-in voltage  and acts like a one-way valve for charge carriers.

The fundamental unit of light is  the photon, which represents the smallest packet of electromagnetic  radiation of a given wavelength.

When a photon from sunlight hits  a solar cell and gets absorbed, it creates an extra free electron and hole,  which are separated by the electric field and pulled to opposite sides of the  cell. This creates a photocurrent. If electrodes are attached  to both sides of the cell, forming an electrical circuit, an electric  current will flow as long as the sun is shining.

The magic of perovskite crystals  lies in their customizability. Single junction solar cells can only  absorb a portion of the solar spectrum depending on what semiconductor material they use. The lowest energy of light that can be absorbed  in a semiconductor is called its band gap.

A semiconductor will not absorb photons  of energy less than the band gap; and the useful energy that can be extracted from  a photon is no more than the band gap energy. This means much of the energy in sunlight goes to  waste when it hits a single junction solar cell, but because the band gap of perovskites can be  easily changed, you can stack perovskite layers on top of each other that are chemically tuned  to absorb different parts of the solar spectrum.

This results in a solar cell with multiple  p-n junctions that can produce electricity from a broader range of light wavelengths  or extract more energy from each photon, improving the cell’s efficiency. So when you stack two solar cells on top  of each other, that’s called a tandem, or a multi junction solar  cell. And when you do that, that actually pushes that efficiency limit  up from 30% to over 40, about 45 and 46%

Theoretically, an infinite  number of junctions would have a limiting efficiency of 86.8%  under highly concentrated sunlight. and it goes higher with more layers, but  it also becomes more expensive and you get diminishing returns. So generally, we talked  about doing two layers or making a tandem, and that that’s kind of the the  real selling point of perovskites.

So perovskite tandems convert more of the  sun’s energy into electricity, rather than wasting it as excess heat. So what are the exact  efficiency percentages we’re talking about here? we shouldn’t expect solar  cells above 40% efficiency, this kind of solar cell for a long, long time.  I think in theory, it could get there. But realistically I think in the 30’s is is  doable, which is still a substantial jump from, you know, what you see out  there on the market today It’s not just performance that’s improved. The nature of Perovskites allow for  manufacturing advantages too.

So you only need less than 1% of this  material that you need for a silicon cell  to absorb all the sunlight. So in theory, you  can save money, you can basically make this stuff a lot cheaper. The cool thing about the  perovskites is that they turn out even though it’s made of this kind of not perfect material,  you can actually make a very, very efficient solar cell. It’s formed at low temperatures. Silicon,  usually you have to crystallize that something like 1400 degrees Celsius, with perovskites, you  can form it at less than 100 degrees Celsius.

So that means that you can actually use  smaller equipment, and you can kind of use more standard chemical processes. And you can  form the solar cells on things like plastics, so things that would melt under  high temperatures you can actually use to make solar cells on. So you can make  something really lightweight and flexible as well. Perovskite Thin films can be made by synthesizing  a solar ink of sorts, and gently heating it until  the perovskites crystallize, just like salt  crystals emerging from evaporating sea water. Now let’s go deeper into the lab,  to take a rare and exclusive sneak peak behind the scenes to see how  Perovskite solar cells are made.

Yeah, so this guy is called a thermal evaporator.  So it’s, it’s one of many kinds of deposition tools that we use to, to put down thin films.  So when you look at a perovskite solar cell, it’s like any other thin film device like an  organic LED, or a cadmium telluride solar cell, it’s got a lot of thin film semiconductor  layers. And one of the ways you deposit some of those layers, is using techniques like thermal  evaporation, where you heat up a source material, maybe it’s silver, or maybe it’s a precursor  for one of your semiconductors. And you melt it, you evaporate it and then you have a cold  surface that you condense on. And that cold surface is actually just at room temperature.  It’s a plastic sheet or a glass sheet,  or even a silicon wafer that  you’re trying to deposit a film on.

The substrate sits at the very top of the  chamber. It’s under high vacuum and you again evaporate this material and it condenses  and forms this uniform thin film and you do that many many times with different kinds of  techniques. And that gets you your solar cell. You can also make perovskite cells  with spin-coating, screen printing, electrodeposition or even printing the material  on a sheet just like an inkjet printer. Here is the end result, a small  rectangular perovskite solar cell.

So this is the side that’s facing the sun,  correct, and this is the back of the cell? Yeah, the side facing the sun is actually you’re  looking through the glass. And on the other side of that glass, there’s a perovskite layer, kind of  sandwiched between the contacts. So the contacts are, what pull the charge out of the perovskite.  So there’s a transparent conductor on that on the close the side closest to us. Then there’s  the perovskite. And then on the other side, if you look at it from you know, from the  backside, there’s these silver electrodes.

It can be any different kinds of metals. But that  side doesn’t have to be transparent because you  actually want the light to reflect back  into the semiconductor not go through.

These solar cells are just lab samples  designed to test different perovskite formulas. And you can see that these different pads,  each of these squares is a solar cell. So we have six different solar cells on one  substrate for for r&d purposes, for testing. Swift solar is trying to create a perovskite solar cell with the perfect mix of longevity and  efficiency ready for commercialization.

So how do you test the cells if it’s a  cloudy day? The sun can be quite unreliable, even in California.

We actually use this, this machine right here. So  this is a it’s a, it’s called a solar simulator. So it’s actually just a fake sun. It’s it’s an LED  array that basically has all the colors basically, it has a lot of different colors  of LEDs something like 20 Different LED colors in an array with optics to make it  really uniform. So the idea is here we don’t want  to have to take our solar cells outdoors and test  you know if it’s raining we can’t test our cells. what are these here. Are these the  circuit boards that the solar panels, that measure the voltage and the  solar panel sit on top of them?

Yeah, measure the voltage and current. So this  is you can kind of see this, it’s the same shape and it’s got a bunch of pads on there. And each of  those like are basically leads to pull out current or measure. yeah, to measure voltage, so or apply  voltage. So you can see we can do 20 of these at  once. And it basically automatically moves around  to test the cells, each of them individually.

Perovskites have improved greatly since scientists  first began testing them, and are now beginning to surpass mono and poly crystalline  silicon cells in conversion efficiency. As perovskites start coming into commercial  usage, where are we most likely to see them first? All the traditional solar applications. On  your rooftop, out in the field somewhere,  in the desert, on commercial rooftops, on  residential rooftops, like those are all fair game down the line. Perovskites aren’t ready for that  kind of, you know, primetime yet, the stability is still challenged, like you’re getting them to last  for 25 years, we can’t No one can say that yet, confidently, we don’t have the field data to  prove that. 

So there’s a lot of engineering work and science to be done to get to that point.  But there’s a lot of applications where you don’t  need 25 year life, right, like a car maybe only  needs 10 or 15 years. There’s things like high altitude drones, right, which are going to be  fully powered by solar, you know, they’re flying the stratosphere at 65,000 feet beaming down  internet. So that kind of thing is needs very, very lightweight solar needs very efficient solar,  it doesn’t need to a 25 year life, you maybe only need a couple years, five years. So that kind of  thing you can imagine being powered by perovskites very soon, same with solar wristwatches or  small IoT Internet of Things, devices. A lot of these kinds of mobile applications where you  can imagine perovskites kind of coming into the market and then eventually improving towards the  rooftop, towards the utility scale applications.

So what exactly are the challenges  that are preventing perovskites from dominating the solar energy  landscape, and changing everything? we’ve spent a lot of time in this lab actually  working on the challenges of developing this technology to a point where it’s ready for, for  production and for scale up. There’s things like stability, which is probably the core problem  for perovskites is, how do you make these cells last effectively, for years in the field, under  high temperatures, a car roof might get up to 80 degrees Celsius, right or more on a hot day.  So you need to be able to like survive those temperatures for years at a time. And I think we  tried to do we do a lot of tests to and iteration on the materials on the device stack, the stack  of materials we use on the design of the device  itself on the packaging, to make sure that  we can survive those kinds of temperatures, high humidities, the different kinds  of environments you face outdoors.The relative fragility of the perovskite material  requires protection to shield this semiconductor layer from environmental stresses and degradation.

The international standards for terrestrial solar panels require harsh testing that  simulates 25 years of being outside.  In these tests panels are heated up and  even battered with simulated hailstones.

The problem with perovskites is that they’re  still relatively new. We can subject them to these  harsh simulated tests that give us a pretty good  idea of their longevity, but we just don’t have  the real world data yet like we do for silicon  panels, which have been in use for decades now. While perovskites are still in the research &  development phase of the technology life cycle, there are many teams all over the world working on improving their efficiency and stability  to bring them into commercial adoption.

The raw materials for perovskites  are abundant around the world, and the solar cells can be made using  relatively simple manufacturing processes. This means that Perovskites can rapidly scale when  they’re ready for mass market commercialization. It’s estimated that Perovskite panels  could cost up to 15 times less per watt than modern commercial silicon solar panels.

In addition, engineered perovskite materials  absorb all parts of the solar spectrum  efficiently to produce the highest possible  power output and Ultra-thin films open the  door to new product formats with unprecedented  power-to-weight ratios and high flexibility.

A future with cheap, abundant solar power  could open the door for a variety of use  cases where current photovoltaic  technology does not yet make sense.

How about these electric yachts I’ve filmed for  previous Electric Future videos. Their range could be radically improved with higher efficiency,  lightweight, integrated perovskite solar panels. We could see integrated Solar panels  on trucks, buses and cars and any other applications where sunlight is not yet considered  energy-dense enough to provide meaningful power.

Imagine buildings covered in transparent photovoltaic glass windows  that generate electricity. It’s difficult to predict the future of solar.  While perovskites are promising, serious  researchers avoid playing favorites. Instead,  they view all technologies objectively based on  increased efficiency, reduced materials usage,  and reduced manufacturing complexity and cost. Solar photovoltaics are the fastest-growing  energy technology in the world today and a leading andidate for terawatt-scale, carbon-free  electricity generation in our lifetime.

If you’d like to better understand some of  the concepts we presented in this video,  it’s important to first learn  the fundamentals of solar energy. Brilliant does a great job of taking  complicated science and breaking it  down into bite sized pieces with fun and  challenging interactive explorations. Master concepts, grasp the fundamental principles, and develop your intuition so you can truly  understand these breakthrough technologies. I’ve taken brilliant courses on  electricity & magnetism and solar  energy, and was impressed with how well they  structure their lessons with clever analogies,  examples, and quizzes to test your knowledge. Brilliant offers a wide range of other  content in topics from mathematical  fundamentals to quantitative finance, from scientific thinking to special relativity,  from programming with python to machine learning. Go to brilliant dot org slash Electric  Future and sign up for free. And also, the first 200 people that go to that link will  get 20% off the annual Premium subscription. We showcase cutting edge sustainable  technology, if you enjoyed this video…please give it a like and subscribe  to our channel. You may be interested  in watching one of these videos next. Thanks  for watching, and let the volts be with you.

Bliss
Author: Bliss

Dedicated to making a positive difference for people, animals, and this beautiful planet!

0
Would love your thoughts, please comment.x
()
x

Your Wellness Specialist Certification Course & Bliss Planet Digital Magazine For Free

Everything is Free on Bliss Planet thanks to our public charity status and the support of our generous sponsors.❤️

Get your online Wellness Specialist Certification Course and the latest digital editions of Bliss Planet. 

 

 

 

Vegan Health Wellness Earth Love

You have Successfully Subscribed!

Pin It on Pinterest

Share This