#24 Perovskite
#24 Perovskite
A cheaper, more efficient and sustainable material for solar cells
Read time: 3 minutes
In this week’s issue you will learn about a semiconductor material that is revolutionizing the solar PV industry: Perovskite
“Perovskite-based technology holds transformational potential for rapid terawatt-scale solar deployment” - US National Renewable Energy laboratory
Top Perovskite News 🗞️
Project PEPPERONI: This R&D project includes several countries and companies and funding above 15 million euros to promote perovskite development in the EU.
New efficiency record: A group of researchers has achieved a 32.5% efficiency for a silicon-perovskite tandem solar cell. The record for traditional silicon PV cells is 26.81%.
Perovskite startup prize: The US Department of Energy launched a $3 million prize competition to promote the creation of viable perovskite solar businesses.
Let’s dive in 🧠
Solar panels are critical in our path to net zero and even though they’ve become significantly cheaper, their efficiency hasn’t improved much.
That’s going to change with perovskites.
Perovskites are a special type of semiconductors.
They exist in nature as a mineral made from calcium, titanium and oxygen (CaTiO3).
Since their discovery in the early 19th century we have developed many materials around perovskites but…
Why are they so important for future solar PV cells?
For that let’s understand how PV panels work. Typical solar cells essentially have 2 oppositely charged semiconductor layers stuck together forming a neutral zone. Ideally incoming photons of sunlight knock electrons out of the neutral zone and then the electrodes in the cell capture that as usable electricity.
Nowadays that semicondutor material is silicon in over 95% of the panels worldwide.
The efficiency of the solar cell drops a lot if there are defects in the material so the cells have to be heated at extremely high temperatures to get rid of the defects. This is a very energy intensive and expensive process.
So what do perovskites bring to the table?
Manufacturing advantages: They aren’t supply limited, like silicon. Production is more straightforward and requires 20 times less material. Thus leading to a smaller carbon footprint and a cost 16 to 40 times lower per square foot. Their structure is also more tolerant to defects than silicon. That eliminates the cost and high energy required to produce silicon cells.
Higher efficiency (the amount of sunlight converted into electricity): Silicon-based solar panel efficiency is between 21% and 22%. The maximum silicon solar cells can reach is between 30% and 32%. This is known as the Shockley-Queisser limit. Perovskites can go beyond that (to around 40%).
Flexibility: They absorb a wider range of wavelengths of light than silicon, which means more of the sunlight hitting the panel can be converted into electricity. Also, since they can be manufactured really thin, unlike the silicon layer, they can be used on all sorts of non-uniform surfaces that are currently economically unviable.
Okay, so if the market is expected to grow at a 34% CAGR between 2020-2027 and the material’s efficiency has increased from 4% to 25% in a decade…
Why isn’t it in every solar cell?
Cons
Durability: Perovskites are quite fragile. They still struggle to stand up to the 25 year warranty of a silicon cell. Oxygen, moisture and heat really damage them.
Manufacturing: So far perovskite solar cells or solar cells that combine perovskite and silicon layers have mostly been produced in labs. Producing them at scale is still a challenge.
Toxicity: Some of the materials used to protect the fragile perovskite layers are toxic (like lead), but other non-toxic materials are starting to be used.
Top Perovskite Companies 💰
Saule Technologies🇵🇱: One of the leaders in the market. They have a flexible perovskite photovoltaic glass. In 2021 they launched the world’s first industrial production line of perovskite solar panels in Poland.
Oxford PV🇬🇧: They are planning the commercial launch of a perovskite-on-silicon tandem cell this year, predicting a conversion efficiency of 27% and a plan to scale up production to 10GW by 2030.
Greatcell Energy🇦🇺: They make perovskite-silicon cells that work great even with artificial light or when it’s cloudy. They claim their PV cells have the lowest energy payback period.
Many other leaders in silicon-solar PV cells manufacturing are also going into perovskites like Jinko Solar, QCells, or Voltec Solar.
❗Extreme knowledge area❗
Niche perovskite website: All the detailed info you could need about perovskites, there’s even a handbook about the topic!
A couple videos: One about all the details to understand how perovskite cells work and their market. One about how silicon PV cells work.
That’s it for today, 1 climate tech topic in under 5 minutes.
Next week… Electric buses! 🤯
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