Apple appears to be addressing iDevice battery drain with a truly energy-efficient option: a portable solar panel charger.

The U.S. Patent and Trademark Office today published a patent application(Opens in a new window) from Cupertino for a power management system that uses the sun’s rays to juice up a Mac or iOS device.

According to the filing, the technology would include a system micro controller (SMC) and a charger. Once plugged in, power would flow to the system from either an AC-to-DC adapter (your typical wall-based charger), or directly through a solar panel’s output before being measured and converted to the necessary voltage.

The PTO granted Apple a similar patent in February. It covered “integrated touch sensor and solar panel configurations,” allowing for touch-based activities and charging at the same time.

Apple picked up another solar-powered patent in early 2011, tipping a voltage converter with an input that could be coupled with a solar power source and an output attached to an electronic load like a portable electronic device. The company said such a system would maintain the solar-power source at a pre-determined range.

Technology covered in patent applications or awards don’t always end up in a company’s products. Apple did not immediately respond to PCMag’s request for comment about its newest patent.

Two years ago, reports surfaced that the company was building a solar farm near its data center in North Carolina to help power the 500,000 square-foot facility. Earlier this year, Cupertino reported 100 percent renewable energy for all of its data centers and various corporate facilities around the world.