[vectorjohn]

What is it that makes solar panels cost what they do, ultimately? Not materials, right? Those are all basically sand and other not so special things. Labor? Isn't it mostly automated? Upkeep of the factories? Input energy?

Maybe it's just all those things together. But it sure seems like if we wanted to it wouldn't be that hard to ramp up production and drive costs down a couple fold. Not that I know how.

[pjc50]

Ah, the good old "I know nothing about this but assume it must be easy"!

It's materials processing. They're only "basically sand" in the sense that glass or microchips are. The key step is purification of silicon, which is like distillation in the liquid/solid phase. It's very energy-intensive. This then gives you a solid cylinder of pure silicon.

To make cells, you slice this like a ham. Except it's extremely hard, so you need a diamond saw: http://www.asahidia.co.jp/eng/wp-content/uploads/2015/05/B51... and, like sawing wood, the material from the cut ("kerf") is wasted.

A surprising amount of recent cost reductions have been due to making the cells thinner and making the cut as thin and clean as possible.

They are then run through some annoyingly toxic chemical processes, given an antireflective coating, have silver wiring attached, and packaged into a glass or polycarbonate fronted housing.

[rsfern]

And the alternative technologies -- e.g. vapor deposition processes for thin film photovoltaics -- aren't exactly cheap either.

[philipkglass]

sand : solar farm :: iron ore : lawnmower

That said, if you increase production scale you can expect module costs to fall significantly. That's what Chinese manufacturers have actually done:

http://pubs.rsc.org/en/Content/ArticleLanding/2013/EE/c3ee40...

A lot of talk about solar trade has highlighted "unfair" competition from cheap, low-quality Chinese modules. But China also has companies making high-quality modules (LONGi, Jinko Solar, Yingli, and Trina Solar were identified as top performers in DNV GL's 2017 PV Module Reliability Scorecard, along with longer-established Japanese, Korean, European, and American manufacturers) and still making them cheaper than European/American/Japanese producers. The greatest difference is scale.

Recently-bankrupt American solar manufacturer Suniva is trying to get the US International Trade Commission to impose a minimum $0.78/watt price on imported solar modules:

https://www.eenews.net/stories/1060057180

https://www.pv-tech.org/news/breaking-suniva-asks-trump-for-...

Suniva made good modules. But it was manufacturing only 200 megawatts of modules per year. And its modules were not more efficient or durable than good imports. The large, high-quality South Korean manufacturer Hanwha Q CELLS is guiding 5500-5700 megawatts of shipments this year. The large, high-quality Chinese manufacturer Jinko Solar is guiding 8500-9000 megawatts this year. American solar manufacturers can't turn a profit so they don't scale up. And they don't scale up so they can't turn a profit. Jinko Solar and Hanwha can stay in the black at price levels that will bankrupt small producers lacking the same economies of scale.

[cpsempek]

Not that I know either, but the quality control process is possibly a source of much cost of production. Every part must pass a series of tests during and after production before deemed ready for sale. Every failure of a test costs time and money. These yield rates are either low with low cost manufacturing, or, high with high manufacturing costs. This could be part of it.

[MengerSponge]

My understanding is that the cost is dominated by panel interconnects and power inverters and whatnot, not by the silicon itself.