It's a concentrator cell, so it's designed to be used with reflectors or lenses to increase the sunlight capture area.
A rough rule of thumb is that you get 1kW/m^2 of raw sunlight, so to get reasonable powers (in the MW+ range) out of a solar installation without needing an enormous solar cell budget, you need cheap concentrators of some sort.
Concentrator cells make a number of tradeoffs in order to make their performance as high as possible (and keep from melting, etc.). I would guess around 22% efficient in one-sun AM1.0; that's about what other concentrator cells in this upper tier do.
If it's slightly cloudy, I could see efficiencies dropping to the single digits, as each of these cells is actually four different cells all wired in series, each sensitive to different wavelengths of light. If the blue drops out, the corresponding cell on the top of the stack acts as a resistor (and it can even burn out, being so thin).
Solar cell efficiency records (particularly for concentrator applications) are like discovering new transuranic elements- extremely useful and interesting at first, then significantly diminishing returns.
To answer your question directly, I am not using an API and I am not scraping anything, I'm just framing Google's pages in a way that I found useful and productive.
