The U.S. Patent and Trademark Office this month granted Apple a patent for a laptop with a unique display unit that not only serves as a solar power supply, but also an external screen and secondary means of touch. This may have set the stage for future solar powered iPhone or iPad devices. Here are the specifics of the patent.
Electronic devices may have housings. A housing may contain a display on its front face and a rear plate such as a plate formed from glass on its rear face. A peripheral housing member may surround the display and rear plate. An antenna may be formed in the peripheral housing member. The rear plate may be formed from laminated layers including a light guide layer. Device hinges may include hinge structures that are integral to the peripheral housing member. A logo may be formed by coating the rear plate with a patterned masking layer. Display structures for the display and the rear plate may be mounted to opposing sides of a shelf portion of the peripheral housing member. The rear plate may be formed from electrochromic glass and may cover photovoltaic cells and touch sensors. Driver boards may be mounted within a clutch barrel perpendicular to the display.
See the patent here