Ahnood's handiwork relies on an array of solar cells that surround and sit beneath the phone's display. Currently, the system averages 11 percent efficiency in its energy capture, with a peak efficiency of 18 percent. Naturally, there are gains to be made. Of the light generated from OLEDs, Ahnood approximates that only 36 percent is actually projected outward. Critically speaking, this also suggests that similar power savings could be achieved with dimmer, more efficient displays, but we'll let that slide. As it stands, Ahnood's system is able to generate approximately five milliwatts of additional power, given a screen size of 3.7-inches. It's hardly sustainable, but if the creation lets us squeeze in a few more text messages on Friday night, we'll take it.