updated 11:02 pm EDT, Fri September 13, 2013
Could indicate an interest in solar power or super-thin conducive materials
Apple has posted a job listing on its website for a "thin films" engineer with experience in the solar industry to join the company's Mobile Devices group and "assist in the development and refinement of thin films technologies applicable to electronics systems." While many outlets have assumed that the listing may hint at the company's use of solar power in future products, it is also possible that Apple seeks to apply the thin-film technology used in solar panels to be applied in other areas, including display and touch technologies.
The iPhone maker has also demonstrated a previous interest in solar arrays, often employing them for its data centers as part of a larger, multi-pronged strategy to both reduce energy use and increase its reliance on "renewable" sources. The company has also patented technologies related to solar power for consumer electronics, including a solar-powered touch sensor. It is even possible that Apple or some other company has come up with a breakthrough on solar array size that would make it practical to use solar panels in electronics to reduce the load on the traditional battery, allowing for longer usage time.
The biggest issue with solar power remains the cost versus benefits on smaller-scale uses. A number of companies have come up with solar accessories and foldable and portable solar panels that can be used to charge a device like an iPhone or even an iPad, but most of these products have practicality issues in addition to cost: a portable solar charger recently reviewed by MacNN required more than 10 hours in bright sunlight to produce enough battery power to fully charge an iPad, and costs $100 (plus $40 for the battery so that the iPad doesn't need to be plugged in continuously). To be fair, prices on solar chargers have fallen dramatically over the past decade.
Precluding any major breakthroughs, a solar panel on any existing Mac product would not produce enough power to charge the devices, but could generate enough to lessen the drain on the main battery for certain functions, augmenting battery life. For example, a panel on an iPad (or incorporated into its screen) might create enough power to run the now-integrated Wi-Fi/3G-LTE/Bluetooth radios in the device in brightly-lit areas. Others have speculated that even a small solar panel incorporated into a large watch display might be enough to keep the device from discharging too quickly, supplementing the battery to ensure a full day's battery life.
Thin film technology has played an increasingly important role in Apple's technology, enhancing the iPhone, iPod touch and iPad as well as reducing weight and bulk. The job description calls for engineers with experience "in either semiconductor processing or solar industries," suggesting that the hire may not be strictly related to solar power. "A knowledge of thin-films in the context of RF shielding is highly desirable," another section reads, hinting that Apple is expanding its exploration of what thin-films can be made to do or incorporate within their structures.