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Casting a Harsh Light On Chinese Solar Panels
New submitter Eugriped3z writes with an article in the New York Times that "indicates that manufacturing defect rates for solar panels manufactured in China vary widely, anywhere from 5-22%. Secrecy in the terms of settlements negotiated by attorneys representing multi-million dollar installations perpetuate the problem by masking the identity of unscrupulous or incompetent actors. Meanwhile, Reuters reports that unit labor costs in Mexico are now lower than in China."
I have a harsh light for their ability to read a PO. We ordered a thousand amorphous panels for a toy and we asked for 4mA in full sunlight except they shipped .4mA panels. They added a decimal to our spec and that was it. And it cost just enough so it's not worth pursuing further, just start over.
Mostly random stuff.
Well, that's the problem with a race to the bottom: sooner or later you do, in fact, hit bottom. This reminds me of how things played out in the desktop PC market a decade ago: really cheap components caused a lot of problems for a lot of name-brand manufacturers. Bad electrolytic caps on the motherboard were particularly pernicious.
The good news is that, eventually, this will probably get sorted out. Producers and installers with brands and reputations (not to mention business contracts) to defend will eventually get fed up with dealing with shitty suppliers, who will either clean up their act, go out of business, or retreat to the purgatory of "known to be poor quality", where there's still plenty of business to be had (see again the desktop PC market), but not much money to be made.
I would never have figured Mexican labor would become cheaper than that found in China. Sure, there's an education gap between Chinese and Mexican labor, but Mexico has been successful at producing exports in a variety of industries. Significant to what I'm seeing in that comparison is that while the "build it wherever labor is cheap" attitude has certainly been prevalent, I have to wonder if rising fuel costs will begin to whittle away at that? Several years ago, a man who ran a raw cotton storage facility told me that the cotton was grown here in Texas, shipped to China, manufactured into completed products, and shipped back to the United States. How much longer can transportation to and from across the Pacific be cost effective compared to other options?
Shipping costs are a major issue when a product has a low value-to-weight ratio. Almost all drywall used in the US is manufactured domestically, because these are massive, heavy sheets and only sell for $10-$20 each at retail. Shipping them across the Pacific would be cost prohibitive. (We did import some drywall from China during the 2004-2007 housing boom, and it was a disaster – much of it leaked hydrogen sulfide gas, corroding pipes and wiring in the affected houses.) Likewise, plywood is mostly made in the Western Hemisphere; it's sometimes imported from Latin America, but Chinese plywood is less common. You can get quality US-made plywood at Home Depot and it's not really that much more expensive than the foreign stuff. Again, this is because shipping costs dominate with a heavy and relatively cheap product like plywood.
Solar panels are big and bulky, so manufacturing them in China and shipping them to the US will become a worse and worse idea as prices drop.
Firstly, solar cells traditionally lose a large percentage of their performance after the first couple of years of use. If the small assemblies are experiencing a 50% power loss after 2 years, then achieving 50% after 7 years on a high-quality large assembly is reasonable. I'm not really sure why people are expecting solar cells to last 25 years.
Secondly, a roof is a rough place to put a solar cell. It is continuously exposed to sun (ironically), which breaks down many plastic coatings. Additionally, the optical surfaces are affected by abrasion from snow, rain, and wind-borne debris. This abrasion rapidly breaks down optical surfaces, which are needed for solar cells. Roofers are very familiar with the abrasion problem - each and every 25 year shingle does not last 25 years. Additionally, popular shingles are made from tar, felt and rock, as opposed to high-tech plastics, for valid mechanical and photo-chemical reasons. Mechanically and photo-chemically, an array of small plastic optical things will degrade significantly over 25 years. Even high-quality optical materials, like glass windows, degrade in roof-top applications over 25 years.
I'm not really sure why people expect solar cells to last 25 years in uncontrolled and exposed applications. Seven years is a tough specification. Two years is realistic, and that sounds like what some of these systems are actually actually achieving.