Are perovskite cells a game-changer for solar energy?

Summary

This video explores the potential of perovskite solar cells to revolutionize solar energy. Unlike traditional silicon-based cells, perovskites are easier to produce, more efficient, and can be printed onto various surfaces. While silicon cells only capture 20-25% of sunlight, perovskite-silicon tandem cells can convert nearly 30%, offering a significant boost in energy efficiency. However, challenges like stability and degradation remain before they can be commercialized. Companies like Oxford PV aim to launch perovskite solar cells by 2024, but questions about long-term reliability and cost persist.

Takeaways

• 🌞 Perovskite solar cells could revolutionize solar energy with higher efficiency compared to traditional silicon cells.
• ⚡ Perovskites can be synthesized easily and don’t require the intensive mining and high temperatures needed for silicon.
• 🏡 Perovskite solar cells are versatile, able to be applied on thin films for small devices or on roofs for larger installations.
• 🧪 The crystal structure of perovskite, ABX3, is customizable with various materials, making it easier to process than silicon.
• 🔄 Perovskite can be processed at near room temperature, making it less energy-intensive compared to silicon solar cells.
• 🚀 Tandem solar cells, combining perovskite and silicon, can convert more sunlight into electricity, with efficiencies nearing 30%.
• 🔍 Stability is a major challenge for perovskite cells, as external factors like moisture and UV light can degrade their performance.
• 🔧 Encapsulation is key to protecting perovskite cells from degradation, but solutions are still in development for commercial use.
• 🏭 Companies like Oxford PV are working to commercialize tandem solar cells with projected market releases as early as 2024.
• 💡 Despite technical challenges, tandem solar cells could generate 25% more energy than current silicon solar parks, pushing solar energy advancements forward.

Q & A

What makes perovskite solar cells more efficient than standard silicon cells?

Perovskite solar cells can capture more sunlight due to their ability to absorb visible wavelengths, while silicon cells primarily capture infrared light. This results in more overall sunlight being converted into energy, especially in tandem cells.

Why is perovskite considered a superior material for solar cells compared to silicon?

Perovskite is easier to process, requiring lower energy and simpler production techniques compared to the energy-intensive process of mining and purifying silicon. It can also be made at room temperature and is more abundant in base materials.

What are tandem solar cells, and why are they promising?

Tandem solar cells combine perovskite and silicon layers to maximize light absorption. The perovskite layer absorbs visible light, while the silicon layer absorbs infrared light, leading to higher efficiency, with some cells achieving almost 30% efficiency.

What is the main challenge with perovskite solar cells before they can be commercialized?

The main challenge is the stability of perovskite structures, which degrade easily due to exposure to moisture, heat, oxygen, and UV light. This degradation limits their lifespan, making them less commercially viable until resolved.

What methods are being used to improve the stability of perovskite solar cells?

Researchers and companies are working on encapsulation techniques to protect perovskite structures from environmental factors like moisture and UV light, which are critical steps in extending the lifespan of these solar cells.

How does the process of creating perovskite solar cells differ from silicon solar cells?

Perovskite solar cells can be created using methods like spin coating or evaporating the material onto surfaces, which are faster and less energy-intensive compared to the complex and high-temperature processes required to manufacture silicon cells.

Why haven't tandem solar cells been commercialized yet despite their high efficiency?

Tandem solar cells haven't been commercialized because their stability issues haven't been fully resolved, and further research and real-world testing are required to ensure they can maintain efficiency over long periods.

What potential do tandem solar cells have in the solar energy market?

Tandem solar cells could significantly boost solar energy production by increasing efficiency by about 25% compared to standard silicon solar parks. If commercialized, they could lead to more efficient solar parks with higher energy output.

What does the cost comparison between silicon and perovskite solar cells reveal about the future of solar technology?

For perovskite solar cells to compete with silicon, they must be cheaper on a per-watt basis. Currently, silicon solar cells cost about 12.7 US cents per watt, and this is expected to drop further. Perovskite cells will need to meet or beat this cost.

Which companies are leading the efforts to bring tandem solar cells to the market?

Oxford PV and Qcells are two companies actively working on tandem solar cells. Oxford PV claims to have solved the degradation issue and plans to ship commercial modules by 2024, with utility-scale solar parks expected by 2026 or 2027.

Outlines

00:00

🔋 Revolutionizing Solar Energy with Perovskite

The video introduces a groundbreaking solar technology centered on a material called perovskite, which is more efficient and easier to produce than traditional silicon-based solar cells. Perovskite cells offer versatility, from small devices to large solar panels. Unlike silicon, which requires mining and high temperatures for processing, perovskite cells can be synthesized easily. The video explores perovskite's crystal structure and its potential to dramatically improve solar energy efficiency, explaining why new materials are needed due to silicon's inefficiency and resource demands.

05:01

☀️ Tandem Solar Cells and Their Efficiency Boost

Tandem solar cells, combining perovskite and silicon layers, can convert nearly 30% of sunlight into electricity. The video explains how these cells work by splitting the light spectrum, with perovskite capturing visible light and silicon converting infrared light. This allows for more efficient use of sunlight, resulting in 50% more energy production compared to single-junction cells. However, challenges remain before these cells reach commercial production, such as stability issues and degradation from exposure to moisture, heat, and light.

10:02

⚙️ Addressing the Stability and Cost Challenges of Tandem Cells

The video discusses the hurdles in bringing tandem cells to market, focusing on their tendency to degrade and lose efficiency over time, much faster than silicon cells. Encapsulation methods to protect perovskite structures are being explored. Companies like Qcells and Oxford PV are developing commercial-size tandem cells, aiming for 26% efficiency over a 30-year lifespan. Despite promising lab results, real-world testing is limited, and concerns about long-term stability and commercialization remain.

📈 Market Potential and the Race to Commercialize Perovskite Solar Cells

The final part of the video highlights the competitive landscape for perovskite solar cells. Oxford PV claims to have solved the degradation issue and plans to release commercial modules in 2024, with utility-scale deployment expected by 2026-2027. If successful, these cells could generate 25% more energy than current silicon solar parks. However, cost and stability remain crucial factors for widespread adoption. The video ends by encouraging viewers to stay updated as this evolving technology could soon reshape the solar energy market.

Keywords

💡Perovskite

Perovskite refers to a type of crystal structure that is promising for solar energy due to its ease of synthesis and high efficiency. In the video, perovskite is highlighted as a potential game-changer in solar cell technology because it is more efficient and easier to process than silicon, which is traditionally used in solar cells. Its versatility in absorbing sunlight and ease of production make it a key focus of modern solar energy research.

💡Silicon Solar Cells

Silicon solar cells are the traditional technology used in commercial solar energy systems, converting sunlight into electricity. The video explains that silicon cells are inefficient, converting only 20-25% of sunlight into energy, and are energy-intensive to produce, requiring mining and high-temperature purification. This contrasts with perovskite cells, which are easier to make and potentially more efficient.

💡Tandem Solar Cells

Tandem solar cells are a combination of two types of cells—perovskite and silicon—designed to maximize the absorption of different wavelengths of light. The video highlights that tandem cells use visible light for perovskite and infrared light for silicon, allowing for higher overall efficiency (around 30%). These cells are seen as a step forward in improving solar energy capture.

💡Spin Coating

Spin coating is a method used in the lab to create perovskite solar cells by spinning a substrate at high speeds to evenly distribute materials and form a thin film. The video describes how researchers use this process to deposit a perovskite solution and crystallize it, although it is impractical for large-scale commercial production. This technique demonstrates the experimental nature of perovskite cell manufacturing.

💡Degradation

Degradation refers to the breakdown of perovskite solar cells over time due to factors like moisture, heat, and UV exposure, leading to reduced efficiency. In the video, researchers mention that while tandem solar cells show promise, they degrade much faster than traditional silicon cells, losing efficiency within months. Addressing degradation is a key challenge for bringing perovskite-based solar cells to market.

💡ABX3 Crystal Structure

ABX3 is the chemical formula for perovskite’s crystal structure, where 'A' is often an organic compound (like methylammonium), 'B' is a metal (like lead), and 'X' is a halide (like iodide). The video uses this structure to explain the simplicity and versatility of creating perovskite cells. This structure allows for various material combinations, making perovskites easy to synthesize compared to silicon.

💡Efficiency

Efficiency, in the context of solar cells, refers to the percentage of sunlight that can be converted into electrical energy. The video emphasizes that perovskite and tandem solar cells can achieve much higher efficiency than silicon cells. Perovskite cells have been shown to reach nearly 30% efficiency in the lab, a significant improvement over traditional silicon cells.

💡Encapsulation

Encapsulation is the process of sealing solar cells to protect them from external factors like moisture, heat, and oxygen that could cause degradation. The video explains that encapsulation is essential for stabilizing perovskite solar cells and improving their commercial viability. Without proper encapsulation, the cells degrade quickly and lose efficiency.

💡Sun Simulator

A sun simulator is a device that mimics sunlight to test the efficiency of solar cells in controlled conditions. The video shows researchers using a sun simulator to measure how much sunlight tandem solar cells can convert into electricity. This tool is crucial in research to provide accurate data on how well the cells perform under sunlight.

💡Cost per Watt

Cost per watt is a metric used to measure the economic efficiency of solar energy technologies. In the video, the cost per watt for traditional silicon solar cells is discussed as a benchmark that perovskite cells need to beat for widespread adoption. Currently, silicon cells cost 12.7 US cents per watt, and this needs to be reduced for perovskite or tandem cells to be competitive in the market.

Highlights

This tiny solar cell, made from perovskite, is more efficient than standard silicon solar cells and can be easily synthesized without the need for mining.

Perovskite solar cells can be used on various surfaces, from powering small devices to being installed on roofs, highlighting their versatility.

Traditional silicon solar cells convert only 20-25% of sunlight into energy, whereas perovskite cells promise much higher efficiency rates.

Silicon production requires energy-intensive processes with temperatures over 1,000 degrees Celsius, whereas perovskite cells can be processed close to room temperature.

Steve Albrecht, a leading researcher at Helmholtz-Zentrum, has set world records for perovskite solar cell efficiency, demonstrating their potential.

Perovskite cells have a crystal structure (ABX3) that allows for various combinations of elements, making it easier to produce them using abundant materials.

The spin coating method is used in labs to create perovskite films, although there are other methods like printing and evaporation for mass production.

Tandem solar cells, which combine perovskite and silicon layers, are currently the most promising in terms of increasing solar cell efficiency.

A sun simulator at Helmholtz-Zentrum helps measure tandem cells' efficiency, which has reached almost 30% in tests, a significant improvement over single junction cells.

Tandem cells are efficient because they utilize both visible and infrared light, increasing the overall sunlight converted into electrical energy by 50%.

The stability of perovskite structures is a major challenge, as they degrade easily when exposed to moisture, heat, oxygen, or UV light.

Researchers are experimenting with encapsulation techniques to protect perovskite solar cells from degradation and improve their long-term efficiency.

Companies like Qcells and Oxford PV are working on improving perovskite cell stability and efficiency, but verified data is still limited.

Although some perovskite tandem cells have shown promising lab results, real-world outdoor tests are still lacking, making it difficult to determine their long-term viability.

Market experts like Jenny Chase believe that for perovskite cells to succeed, they need to be cheaper than silicon cells on a cost-per-watt basis, which is currently challenging.

Oxford PV claims to have solved the degradation issue and plans to release commercial modules in 2024, with large-scale solar parks expected by 2026-2027.

Transcripts

This tiny solar cell might be about

to revolutionize solar energy as we know it.

It's way more efficient

than a standard silicon solar cell...

it can be easily synthesized —

so it doesn't need to be mined like silicon.

And it can work on thin film to

power your smart home speaker,

but it can also go on your roof.

Say hi to this crystal structure called perovskite.

It promises improvements to solar cells

that are almost too good to be true.

But WHY would we even need new solar cells?

Well for starters...

...the regular solar cells you know

are made with silicon.

And they are actually quite inefficient

at converting sunlight into energy.

Only about 20 to 25% of sunlight

can be captured on a commercial size.

But that silicon needs to be mined.

And purified in energy intensive processes

that require more than 1,000 degrees Celsius of heat.

If you want to know more on this,

we have a full video on that here.

But a new material called perovskite

might actually be able to solve all of this.

To understand why they are so superior

to your standard silicon cell,

I went here:

the Helmholtz-Zentrum in Berlin.

They've been researching perovskites

as sun absorbing materials

for about a decade.

And this is the guy in charge of the research:

Steve Albrecht.

He's even set world records

for the most efficient perovskite solar cells.

"So on a very basic level:

What does perovskite look like?"

"The term perovskite is a very generic term

for a specific crystal structure, right.

You can see that over there.

So the crystal structure has the ABX3 formula

and like, each component is a certain

either element or a molecule.

One of the most common combinations

in this structure is methylammonium

as the A on the corners,

the metal lead for B in the center

and the chloride or iodide as the X

which form around the metal.

But there is quite a vast range of materials

that can be used and combined.

And it's quite wild how easily

these can be put together.

"Oh, this is a lab environment!"

But before we do that: security first

as we are going to work with toxic lead

with one of Steve Albrecht's colleagues.

"You look a bit like a veterinarian."

"Yes, these are veterinary gloves"

Ok, time to get in our base materials.

Matthew mixes methylammonium chloride

and lead iodide to later create

our ABX3 crystal structure.

By the way,

everything happens in these boxes

so that no water or oxygen

comes in contact with our precious perovskite.

"What is now the advantage of these materials

compared to silicon?"

"I believe that one of the main advantages

of perovskite over silicon as a material

is the ease of processing.

So, silicon is something that is relatively

energy intensive to fabricate,

but this is something that can be done at

close to room temperature.

It doesn't require much energy,

so it's easy to do.

Everything is relatively abundant

and so it shouldn't be a bottleneck for production."

So, these base materials are more abundant

than silicon and are easier to process.

Now we have the base materials,

but how do we make

a sun absorbing perovskite out of it?

"So, I deposit the solution of perovskite

and then it spins up quite fast,

so something like 4,000 revolutions per minute.

And then I drop on this anti-solvent solution

and that drives the crystallization

of the perovskite film."

The method that Matthew is using here

is called spin coating.

But perovskite solar cells

can also be directly printed onto surfaces,

using similar processes

to those used for printing newspapers.

Another method

is evaporating perovskites onto surfaces.

Spin coating usually takes place

in a lab environment

and it can be tedious.

Matthew accidentally dropped the glass.

Not a big problem in a lab environment,

but for commercial production

this is not viable.

Matthew gives it a second try

and this time everything works.

After the spin coating

it goes onto a heating plate

and the darkening shows us

that the crystals are being formed.

It works the same way as when

salt water evaporates

and you start to see the salt.

"There are cells like this one here

which are only made out of perovskite,

but in many cases

there's a silicon layer beneath them.

These cells are called tandem cells

and look like this.

Right now,

they are the most promising candidates

when it comes to increasing

the efficiency of solar cells.

But at some point,

it might be possible to abandon silicon completely.

To test their tandem cells efficiency,

the researchers at the Helmholtz-Zentrum

use a sun simulator.

It determines exactly how much sunlight

is converted into electricity.

"What kind of efficiency did we just measure?"

"Here we measured almost 30%.

Quite a nice achievement."

"Why does a tandem solar cell reach

that much more efficiency

than single junction solar cells?"

"Tandem solar cells make much more use

of the incoming light.

So we have our solar spectrum

and the solar cells,

they share the spectrum.

The perovskite solar cell in this case

makes use of the visible wavelengths.

So everything that we can see by eye

is then converted into perovskite solar cell

into electrical energy whereas the infrared light

passes through the perovskite cell

and is then converted into silicon solar cell

which is quite efficient

in converting infrared light.

So, they share the spectrum

and each cell is very efficient in their region."

It doesn't sound like that much,

but Eike tells me this way,

roughly 50% more sunlight can be converted

into electrical energy.

So more overall sunlight can be absorbed.

But you can't buy any of these tandem solar cells yet,

because before they go into serial production

there is a lot of stuff that needs to be fixed.

A major issue

is the stability of perovskite structures

used in tandem solar cells.

Perovskite structures are easily put together

at low temperatures as we saw earlier,

but they also come apart easily.

Even the charges

that travel through the perovskite in a solar cell

can create defects

and destroy the perovskite structures.

Also, external factors like moisture, heat, oxygen

and UV light can break it down further

and quickly decrease its record-breaking efficiency.

This whole process is called degradation

which researchers and companies are trying to fight

with different forms of encapsulation.

It seals off the solar modules

from external influences

and is an essential step for commercialization.

Qcells which is part of a European academia

and industry partnership,

plans to develop commercial-size modules

with an efficiency of 26%

over a lifetime of 30 years.

Oxford PV,

a company founded by Oxford University graduates,

has reached an efficiency of 28.6% and supposedly

solved the degradation issue already.

But both companies

haven't published verifiable data yet.

There also isn't even a lot of research

on real world outdoor tests.

"These are a lot of solar cells

that you test here. Wow!"

This is Carolin Ulbrich.

She oversees

the degradation tests of tandem solar cells

at the Helmholtz-Zentrum.

"At what kind of stabilities

are we currently looking at here?"

"Sometimes they fail after a few days,

but sometimes they last for years."

Ulbrich's team measured a loss of 20% in efficiency

in just half a year.

Other researchers, in Saudi Arabia for example,

came up with similar results.

For comparison,

it takes silicon solar cells roughly 20 years

to reach that level of degradation —

a number that tandem solar cells

would need to match.

"Some companies say they already fixed this issue

and are ready to go to market next year.

Do you believe that's possible?"

"We do sometimes hear rumors

also at conferences,

but they normally don't show the data.

It's all very secret.

I assume that they will in the next years

produce samples

and that is very important to do because then

you can test them on your own sites, in PV-fields,

and before you commercialize them,

before you sell them to customers,

you can test inside whether it's really true

because it's really hard to say about

these samples that we have out here —

after one year -

that they're going to last for 25 years."

And until now,

we've only talked about

the technical side of things.

But tandem solars have another thing coming:

"If perovskite is going to go anywhere,

it will need to be cheaper

than ordinary crystalized silicon

on a per watt basis."

This is Jenny Chase.

She has analyzed

the solar market for 18 years and founded

the solar analysis team at Bloomberg NEF.

"They've got to beat them on the cost per watt,

which is currently 12.7 US cents per watt,

and it'll be 12 by next year."

According to the

International Renewable Energy Agency,

since 2010, costs for electricity from solar

have declined by 89% globally.

It's now more expensive

to install silicon panels

than it is to make them.

Meaning the limiting factors for solar

aren't the manufacturing costs,

but grid connection,

land permits or labor for installation.

"It really comes down to the company

that solves the cost and the stability factor

and manages to get these into

stable volume production

will make a lot of money.

If nobody does,

then solar will still get built."

One company, that claims

it has solved the degradation issue,

is Oxford PV.

It says that, together with partners,

it can ship out modules in the middle of 2024

and that we'll have utility scale solar parks

with tandem cells in 2026 or 2027.

Looking at today's efficiency numbers,

solar parks like that

would generate 25% more energy

than comparable silicon solar parks.

Solar tandem cells have a great potential,

but there are still a lot of things

that need to fall into place for them to work.

And I'm really really curious

if they are actually going to be

on the market next year already.

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