Solar panel efficiency ‘research race’ ongoing as technology dashes toward records

The solar panel industry is fighting physics’ stubborn hold on the secrets of photons exciting electrons – and the results of this atomic level focus are showing up for regular people.

A trio of solar efficiency records have been brought forward recently: Hanergy’s thin film unit developed a 25% solar panel, Trina Solar broke 25% with an IBC solar cell, and a lab in Europe has set an amazing record of a 26% solar cell using a standard, simple ‘p-type’ technology.

Solar cell efficiency increases mean a lower cost for the electricity being produced because you can use much of the same hardware, and labor, to install a larger amount of energy. A few years ago, one person could easily carry a 250-280W solar panel, and today that same worker is carrying 290-325W solar panels. 16% more energy being moved with the exact same physical motions.

A key point you’ll see is that, much like the sport of professional boxing, there are many ‘record solar cell efficiencies’ because there are many product types. As such, if you get a little confused about which solar panel is the best…well, it’s a great debate in the industry among the experts – and only time will show us the winner(s).

The map below (full sized file here – pdf) gives you a taste of the many different product types and their respective efficiencies.

There are exotic solutions with crazy efficiencies – perovskite with its promise at 26.4% and, of course, multijunction products used only in space or the most demanding projects that go up to and above 45% efficiencies.

NREL Best Research Cell Efficiencies

It’s thought that a super high-efficiency bifacial, glass on glass solar panel (something like being developed here) was what drove the record 1.79¢/kWh bid for solar power in Saudi Arabia. It’s also mentioned that the newness of the technology might be one of the reasons the bid was discarded. Sometimes you can be too cutting edge for your own good.

What’s also cool is that as we continue covering solar panels here, we’re getting to see aesthetically pleasing, high-efficiency, products being pushed into the residential market resulting from these research initiatives. Solaria and SunPower are making use of shingle cells, Solertech Universal pushing heterojunction, LG using N-type cells and ‘ribbons’ or backside busbars, and JA Solar pushing monoPERC – all the while we’re gaining longer panel lifetime as our manufacturers better their techniques.

Jinko vs LONGi

In the fall of 2017 – from companies that are making huge amounts of solar panels today – we saw a trio of record-breaking efficiencies for ‘p-type monoPERC’ solar cells. Coming in tight succession from Jinko Solar, then LONGi, and then followed up by Jinko Solar again! I would bet that JinkoSolar made their announcement, and LONGi, knowing they had a record in the lab, jumped to respond the very next day. There’s obviously a lot of value to be had in saying your research is leading the world.

‘Lab Sized’ POLO solar cells

26.1% POLO

Much like I was excited to see the Jinko Solar and LONGi announcements, since they’re real world companies making real products in large volumes, I am most excited reading about the 26.1% efficient solar cell coming out of The Institute for Solar Energy Research Hamelin (ISFH) and The Leibniz Universität Hannover.

The key point:

“Our result demonstrates that neither n-type silicon nor boron-diffusions, nor amorphous silicon are a must for ultra-high efficiencies. There are also other attractive pathways to highest efficiencies with silicon at potentially low cost!”, states Prof. Rolf Brendel, director of ISFH.

This product is close to what is widely manufactured in the world – meaning it’s closest to you and I, and having a wide scale effect. Researchers suggested it was a relatively simple change – one machine with a different laser – to solar panel manufacturing lines that would make it possible to add these efficiency benefits. Of course, these machines don’t exist yet because these solar cells are ‘lab sized’ not ‘large area’, and it’s going to take time for this knowledge to move to manufacturing lines, however – per the researchers, it shouldn’t be a large leap. And that’s exciting.

‘IBC’ vs ‘Standard’ solar cell

25.05% IBC

Trina Solar has set a new record of 25.04% total-area efficiency for a large-area n-type mono-crystalline silicon Interdigitated Back Contact (IBC) solar cell.

But wait – IBC solar cells are what SunPower has made its name on, and they have been above 25% for a while. Here is where you get to see the subtle nuances of solar cell hardware creating a new record class for sexy headlines. SunPower’s solar cell size is smaller than Trina, and SunPower is actually moving to this solar cell size themselves per this conversation on Twitter with Mark Osborne (the person I get most of my upstream solar manufacturer knowledge from), thus the large-area denotation. Plus, this could very well be an ‘in China’ record per Mark, we’ll find out after the Chinese New Year (happy New Year, China!).

A key point made by Mark is that a company like Trina moving into this cell type, and doing it in an industry standard size, will lead to tool standardization and mass market adoption – dropping costs. This solar cell – SunPower’s specialty – has been the driver of the most powerful solar panels available to regular people (not NASA) on the planet. And if Trina Solar, the second largest solar panel manufacturer on that very same planet, is the company to bring this technology to the masses, we all win.

Hanergy ‘Thin Film’ solar cell

25.1% solar PANEL (not solar cell)

Hanergy, via Alta Devices’ R&D, has announced a thin-film Gallium-Arsenic (GaAs), flexible solar panel with an efficiency of 25.1%. The product is directed toward specific markets that can make use of the thin, light flexible aspects of the product – space and military applications at the top of the line, and also drones and automobile windows. The company that makes the solar cell in this panel also has a dual junction solar cell that peaks at 29% (PDF)!! The challenge with this product is scale/price as of right now – but holy heck – a 25% efficient, sorta normal solar panel is in the world.

Electrek’s Take

Scientific research has a real affect on your and my life, and this field of research driving clean energy production is going to save billions of human lives. Advances in medicine and food production have allowed humanity to absolutely dominate the surface of this rock. Cleaning our energy will allow us some serious time to figure out how to integrate, feed, educate and manage the next 7.3 billion of us.

Considering residential solar? Understand Solar will connect you with local contractors, Tweet Me an I’ll give you some feedback or allow me to give you a professional residential consultation that will save you money.

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