(If you've missed the earlier Solar Fred in China posts, see Part 1, Part 2, and Part 3 here.)

After a hotel breakfast, a tour bus picks us up and drives through Changzhou's broad avenues, crowded with more cars and trucks going to the many factories in this city of 2 million residents. Trina is certainly not the only employer here, and informs us later at a post-tour press conference that it has 13,000 people working on its 4-block campus.  (Globally, they have 17,000 employees.)

We know we’re approaching Trina by the row of street lamps powered by solar PV panels. As the bus enters the campus grounds, we can see the frames of new buildings under construction. Trina is part of China's new construction trend, expanding their manufacturing, as well as their R&D buildings.

Stepping out of the air conditioned bus, we’re quickly led out of the May heat and humidity into an air conditioned showroom. The large room contains some PV models, photo-displays of Trina’s history and landmarks, as well as a wall of interactive touch screens that were part of last year’s World Expo 2010 in Shanghai.

After a quick snapshot of the showroom's ingots (pictured), we are told to put away our cameras.

A freight elevator brings us down from the showroom to the factory floor level.  Throughout the tour, we are able to see through a large glass window that shows each processing machine and the workers that man them, but we never actually get to go on the floor or see anything up close. A guide explains what each machine and worker does. Some workers notice us looking at them through the glass, but mainly remain focused on their tasks.

I wish I could have been able to take photos, as it not only would have helped to describe to you what we saw, but it would also give you the sense of how complicated manufacturing solar PV can be, from slicing the ingots, to producing cells, and assembling the panels that we all take for granted.

To sum up what we saw in a blog post without visual aids would be boring. Honest. There’s so much to tell and so many technical details. On second thought, even if I did have photos, only the geekiest of solar PV engineers might read all the way through. However, if you want a sum-up of the entire module making process, here’s a link to Trina’s web site.

Otherwise, here are the highlights that impressed me and my memory most, in general terms:

  • There’s a lot of validating and grading going on through the various stages. Some validations are performed by machines and others by humans, who are checking for tiny telltale flaws in the wafers or cells.
  • One of the machines we see is responsible for reducing reflections, so that cells capture more light and add to cell efficiencies. The proprietary process uses plasma enhanced chemical vapors to enhance the absorption of sunlight. It makes the cells only a little more efficient, but every bit counts, and that’s kind of the point of many of the processes we see.
  • Soldering cells together is done by some humans or automatically by machines. Trina is in the process of testing which method is most effective. Humans have an advantage of being able to act as an extra QC check, but the machines are faster. Are they more accurate and more cost effective than humans? Trina says this is to be determined in the future.
  • I sometimes feel like we’re in a high tech library. In addition to checking for flaws, workers do a lot of categorizing and stacking of cells into little slotted containers. Trina says they are trained to spot these flaws, and I wonder what features they are looking for when they see so many wafers and cells, every day, over and over again. 
  • Everyone is wearing masks and protective clothing. There are a lot of proprietary chemical processes and acid baths that wash the wafers. Of course, dust, human hair, etc on PV cells is a no-no, so the clothing serves two purposes.

In about 45 minutes and several elevator rides, we’ve seen the entire process, from slicing ingots to a completed solar module. We move on to Trina’s testing facility.

There are neat crisscrossed stacks of marked PV panels waiting to be tested. Again, we cannot take photographs, but the battery of test stations include all of the standard tests that comply with pretty much every certification agency in the world—plus some extra tests. There are temperature tests, hot spot tests, weight load tests, a simulated collision test for hurricane debris, an x-ray test, and many, many more testing stations.

If my notes are correct, about 1 in every 100 modules go through testing, in addition to some R&D testing. Any QC problems found can be traced back to the machine or even to the shift worker(s) who made the flawed wafer, cell, or panel.

There is a press conference afterword with a power point presentation and a Q&A with Trina’s CEO, but I will save that experience for the next post.

***

The tour is over and obviously I'm impressed, but is that really surprising? Trina is already a well-respected name in the solar industry. It’s on a short list of solar companies that are repeatedly listed as “bankable” 

Even if my headline had suggested that I was underwhelmed by the tour, I would hope that you would trust the bankers and their army of technical analysts more than Solar Fred having a an hour factory tour. Please.

So what's the point here? Like all press junkets, this is not a technical quality verification tour, but a public relations tour, and I must say that it was effective. It’s one thing to touch the final product, but when you see, first hand, all of the details and machinery that go into producing the panels… it does give one confidence that you’re selling and installing a quality product. The subsequent Trina CEO press conference we have—details in a future post—also adds to that confidence.

Now, does this tour convince me that solar PV is not just a $/watt commodity and that Trina’s factory tour is a great example for why it’s not? I’ll have more thoughts on that in a future post. Until then, as always, UnThink Solar.

Tor Valenza a.k.a. “Solar Fred” advises solar companies on marketing, communications, and public relations. Contact him through UnThink Solar or follow him on Twitter @SolarFred. (Please note that Trina is NOT a client, but did pay the expenses for me and about 30 other reporters to visit their factory.)