Commercialization of concentrated photovoltaics

Question

How are multi junction solar cells are fabricated and encapsulated?

Answer

The question implies that such CPV systems are not industrialized (commercialized?). That is actually false - multiple companies have commercial product of CPV systems (e.g. Soitec, Suncore, etc). It's just that compare with flat panels (Si, CdTe, CIGS... etc), the market share of installed CPV has been very low. (GreenTechMedia reported that CPV has a 0.25 percent global market share of the 40 gigawatts of PV being installed in 2014.)

CPV systems cannot compete with flat panel systems on cost (either $/W or LCOE), for several reasons:

• The 40%+ efficiency you quoted are the efficiency of the solar cell itself, but the CPV system is more than just the solar cell. Once you factor in the system-level losses (secondary optics, tracking systems, etc), the system-level efficiency is on the order of ~25%, give or take. (Source: Current Status of Concentrator Photovoltaic (CPV) Technology (2016))
• CPV only works under direct sunlight. The diffuse component (~10% of total insolation if I recall correctly) is not captured at all. If there is a cloud blocking the sun, your system level efficiency will drop very close to 0%. This limits their geographical reach.
• High-concentration CPV requires two-axis tracking system which requires frequent maintenance. This is exasperated by the fact that a lot of CPV are deployed in desert areas, where there aren't many clouds but there are sand and dust covering the mirrors and clogging the cogs, etc.

FYI, the NREL/Fraunhofer joint report on Current Status of Concentrator Photovoltaic (CPV) Technology (2016) has a lot of good information if you are interested in learning more. This table captures the pros and cons of CPV pretty succinctly.

(Original answered on quora: What is blocking concentrated solar cells (50-100x factor, 40% efficiency) from being industrialized?)