As solar panels baked in the sunlight on his warehouse rooftop, Eric Simon smiled from behind his sunglasses. The bar graph on his phone app edged higher to show the new solar system generating enough power to run the huge building beneath his feet. The stream of sunlight knocked electrons free from atoms in the dark blue silicon, creating a flow of nearly 2 megawatts of electricity, enough to operate the family-run Michael Lewis Company facility in southwest suburban McCook.