Opinion

Beyond PERC Will Likely Have To Wait

LONGi, the world's largest mono wafer manufacturer, is a driving force to push solar wafer technology from multi to mono. It is also very active in the field of PERC solar cells, where it is one of only two companies - together with JinkoSolar - that have exceeded the 23% efficiency level for that technology.

Michael Schmela

When talking with solar experts about PERC these days one could get the impression there is little to exchange. PERC is now the new standard for monocrystalline cell technology, which is quickly expanding its shares and is expected to leave its less efficient family member multi soon behind, in particular after the world largest and long-time exclusive multi wafer manufacturer GCL recently announced that it will soon strongly invest in mono wafer production capacities.

Instead of talking PERC, both equipment manufacturers and cell manufacturers like to share their views about alternative or next generation technologies. Understandable, one wants to sell equipment and exploit new business fields, the other wants to find the next cell technology to differentiate from the competition.

But PERC has just arrived, is now establishing itself, and doesn't look like it's going away anytime soon.

First of all, PERC just reached less than 20% market share in 2017, and might, if all goes well and our optimistic estimates are correct, reach around 45% this year. This leaves still quite some room to grow.

Moreover: With so many cell manufacturers now active in PERC production, there's real momentum in R&D.It has been amazing to see how quick efficiency records have been falling recently. In the last 12 months, since we published the 2017 edition of our PERC report, the efficiency record was broken 
6 (!) times. And it's not only about the frequency, but even more about the high level of the recent records.

The ISFH/SolarWorld roadmap towards a 24% PERC cell was considered by many experts an unrealistic target. However, in Oct. 2017, LONGi announced a new PERC world record, which exceeded for the first time the 23% level. The company said this 23.6% commercial size cell was based on pure PERC technology. The current world record, announced by JinkoSolar in May 2018, is already knocking at the 24% door. However, JinkoSolar said that its record cell is based on a PERC platform though it uses also passivated contacts, which is considered another very promising future crystalline cell technology.

That's why it looks like the next big thing after standard PERC is what we call PERC+. Using selective emitters, everything the advanced module tool-box has on offer (half cells, multi busbars, bifacial) or the combination with passivated contacts. All this shows quite some further potential for PERC to turn the world records into solutions that can be mass manufactured as well, and thus supporting its successful march.

There is also a lot of potential for other crystalline technologies that are similar to PERC, like PERT or PERL. For both, there is already mass production experience. N-type even offers higher efficiency potential and better bifaciality than PERC. All that would also speak for heterojunction technology (HJT), although the production process is much different. (For details on these alternative technologies, check chapter 8 in our 2018 PERC+ Report). However, the window for many of these PERC alternatives is closing quickly.

Because once a train is rolling at full steam – and that's the status of PERC today –, it's very difficult to stop it. The more stakeholders are involved with a technology, the better are usually the R&D results, the faster you see progress in development, while a gigantic mass production machine leads
to economies scale, resulting in significant cost reduction.

So even if solar experts prefer to discuss potential fancy alternatives, it is very likely that they will have to talk about and work on the new standard cell technology for quite a while, no matter if it is called PERC or PERC+. The Beyond PERC scenario will have to wait.

You can download our new TaiyangNews PERC 2018 report for free here.