On a recent flight from Los Angeles to Phoenix, I glanced out the window as the aircraft slowly descended over the open desert west of the city. The landscape shifted abruptly from endless scrubland to an expanse of mirrored rectangles stretching to the horizon. I took several pictures, and my phone’s GPS later confirmed what I was seeing: the Mesquite Solar Complex in Arlington, Arizona—one of the largest photovoltaic installations in the United States. From above, the site resembles an enormous geometric tapestry. On the ground, it…