“Solar modules can now reach 39.5% efficiency!”
You might have heard some exciting news in the form of enthusiastic headlines boosting new, ultra-efficient solar cells. We are excited for all solar innovations. It is true that scientists created a new type of solar cell that can reach higher efficiencies than traditional solar cells, but there’s a lot more to it!
As one of the best solar companies in Virginia, we aim to make solar accessible to you— even its innovations.
When we heard the news that a manufacturer created a perovskite-silicon tandem solar cell that achieved 33.84%, we thought, Great! Can’t wait to install these super-efficient panels on some roofs!
Current solar panels only have a power conversion efficiency (PCE) of 22.8%— max! PCE is the amount of solar energy that can be converted into electricity. The first solar cell ever invented only had a PCE of 1%. But that was back in the late 1800s. We’ve come a long way since then, so higher PCE must be the future!
If a modern panel produces 400 Watts over 1 hr of peak daylight, then a new innovative panel (with 33% PCE) could produce 600 watts!
That means you could achieve the same results with fewer solar panels. For example, a modern 9.9 KW solar system needs roughly 27 solar panels. That’s based on the success story of the Harrisons. Read their whole customer testimonial to learn how they achieve energy independence.
In the future, the same 9.9 KW system could be achieved with only 17 panels. So less material costs for you, making solar much more accessible.
That all sounds great, but these experimental panels have hurdles to overcome before they become commercially available.
So, let’s step through this exciting innovation and learn how it works. Let’s examine the obstacles perovskite-silicon cells have to overcome. And even if these new solar panels never reach your roof, they might still have an impact on your future.
First, how do solar panels work?
Think back to high school chemistry. Every atom has a nucleus surrounded by electrons organized by energy levels called shells. The outermost electrons are in the valence shell or band. If those valence electrons gain energy, say from sunlight, then they can jump to the conduction band. Electrons in the conduction band can move freely through the material, creating electricity.
The energy needed to jump an electron from the valence shell to the conduction band is called the bandgap. Conductors like copper have no bandgap, so the valance shell and conduction band are one and the same. Insulators like rubber have a high bandgap, preventing the flow of electrons.
Solar cells are made of semiconductor materials with a Goldilocks bandgap. If you have solar panels on your roof right now, they are probably comprised of monocrystalline silicon solar cells. These silicon crystals have a bandgap that corresponds with visible light. So, through simple exposure to sunlight, these silicon crystals can generate an electrical current.
How are perovskites an improvement?
The word perovskite comes from a mineral that naturally forms cubic crystal structures. If you’ve ever seen a rock with metal-looking cubes jetting out of it, like at a natural history museum, then you’ve probably seen perovskite.
Solar manufacturers can create a semiconductor material that follows this special crystalline structure. Manufacturers can “fine-tune” the perovskite’s bandgap in the creation process. In essence, you can tune a perovskite cell to absorb sunlight that is outside of the silicon cells’ bandgap. Thus converting more light into electricity.
You know how light is made up of photons? Well, these photons carry different amounts of energy depending on where they fall on the electromagnetic spectrum. This energy is measured in units called electronvolts (eV). Silicon solar cells have a bandgap equivalent to around 1.2 eV. However, perovskite solar cells’ bandgap can be adjusted to anywhere between 1.3 to 2.3 eV.
So, you can use a perovskite cell in tandem with another perovskite cell or a silicon cell to capture multiple wavelengths. Imagine if a soccer team had two goalies working together to block more goals than one could possibly achieve alone.
The perovskite-silicon tandem solar cell mentioned earlier uses both a new perovskite solar cell and a traditional silicon to achieve higher efficiency.
A recent PV article states that JinkoSolar, a Chinese solar manufacturer, achieved 33.84% PCE from this experimental solar cell.
China is not the only country experimenting with perovskite-silicon tandem solar cells. Saudi Arabia’s King Abdullah University of Science and Technology (KAUST), achieved a PCE of 33.7% with their perovskite-silicon tandem in 2023. The United States Department of Energy invested $20 million across several diverse perovskite research initiatives.
The Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) in Germany believes perovskite-silicon tandem solar cells could potentially reach a maximum PCE of 39.5%!
If everyone wants high-efficiency perovskite-silicon cells, why won’t we see them on the market anytime soon?
Perovskite-silicon cells are very new, and we don’t know how their performance will degrade over the course of decades. The industry has over 50 years of experience with traditional silicon solar panels; we understand how they perform and degrade. Manufacturers can confidently give 25-year-long performance warranties. To learn more about solar panel degradation and how to keep your system running for decades, check out our blog: Solar Panel Maintenance 101.
JinkoSolar has launched a solar plant using perovskite-silicon cells, but its primary purpose is to study their life-long performance. Who knows, they could degrade faster, slower, or at pace with traditional panels.
Secondly, perovskite cells require lead. As we discussed in The Future of Residential Solar: Emerging Technologies and Trends, lead poses a serious safety concern. On the one hand, the amount of lead required is pretty minimal. On the other hand, what if a perovskite breaks, exposing you or solar workers to lead? Manufacturers are trying to combat this safety concern with sturdier outer shells, but only time will tell.
Finally, perovskite-silicon cells are just not economical to manufacture. Right now, US manufacturers could produce perovskite-silicon cells at around $0.35/W. However, traditional monocrystalline silicon cells can be produced anywhere from $0.20/W to $0.30/W. The difference isn’t too bad, so perovskite-silicon cells could become cost-effective and competitive in the near future.
As Jacob J. Cordell, a researcher from the US Department of Energy’s National Renewable Energy Laboratory (NREL), explains, “If the tandem modules’ costs are high right now, it doesn’t mean it will be the case in two years. A larger perovskite industry may contribute to changing this picture.”
So, these panels might not be the future of residential solar, but they might be the future of utility-scale solar projects.
The vast majority of internet traffic, including this very web page, passes through a data center— probably multiple data centers. These are massive industrial buildings hosting a gigawatt’s worth of servers.
They are not very common in the Chesapeake or Virginia Beach area. But if you ever head up to northern Virginia, the area outside of DC is known as data center alley. Loudoun County is the world’s largest concentration of data centers. But potentially not for long.
2020 sharply increased the demand for data centers, and that demand has only exploded with widespread AI applications like ChatGPT. Data centers already require vast amounts of electricity, not just to run their servers but to cool and protect them. An AI-enabled server rack can require three times the power of a non-AI rack.
Why bring up Data Centers? Because solar has and will continue to influence them.
For example, energy storage technology. We discussed the innovations of lithium-ion batteries in Battery or No Battery: a Buyer’s Guide to Energy Storage Options. Those advancements empower data centers with a clean, ready-to-use power backup in case of outages. This is a major competitive advantage because even a brief power outage can cost the data centers millions of dollars.
Data centers are popping up all over the country right now. Their massive power demands are straining an already aging infrastructure and stressing out the surrounding communities with higher energy bills. But there is a push from both the industry and the public for better sustainability.
Data centers could become the first adopters of high-efficiency perovskite-silicon cells. Having these lead-laden solar panels centralized to utility-scale projects means we can be protected from lead contamination. Data centers already impose high-security precautions. So, they can operate and maintain perovskite-silicon cells with greater safety than any individual house. Data centers can also afford the greater investment of current perovskite-silicon solar modules.
Solar is the Future. Your Future!
Perovskite-silicon tandem solar cells definitely have a place in the future.
But what about right now? What about you?
There’s no need to wait for futuristic solar panels; you can enjoy the cutting-edge of solar technology right now!
They say the best time to plant a tree was 20 years ago. The second best is today. So, achieve energy independence. Stop paying for last century’s fossil fuels. Pave the way for a brighter future.
Contact us, your friendly neighborhood Solar Company in Virginia Beach, today. Schedule a free site assessment to start planning your energy freedom.
