Solar energy can act as an anti-aging ingredient for almost any product. It is able to rejuvenate some of our oldest, seemingly outdated gadgets, and give them fresh appeal for the techie and the environmentally conscious consumer alike.

For example, the transistor radio of yesteryear seems as old as dirt when compared to iPods, online radio and MP3-playing sunglasses. But a mixture of solar power and smart design has revived this nearly diseased device. Here are three solar-powered models that are bringing the radio back to the fore.

The American Red Cross FR-150 Microlink

It is a portable, solar-powered AM/FM Weather band radio that’s good for leisure or, if necessary, emergency scenarios. The multi-feature device — which also acts as a built-in flashlight and cell phone charger — is charged via a small photovoltaic cell and/or by a hand crank. The FR-150 also lets users tune in to FCC and EAS public alert systems, and grants access to weather forecasts and other emergency services via the Weather band receiver. It’s an ideal all-in-one solution for any emergency kit or outdoor expedition.

The Flexio

The Flexio pushes the limits of clean-energy design in the field of personal electronics. In creating this flexible solar radio, designers have done away with the boxed look of a conventional tuner. The Flexio is the size and shape of a woman’s wallet and, depending on your tastes, can be just as fashionable. Both the speaker and solar cell are flexible, which allows the radio to be folded and stashed almost anywhere.

What’s the catch? The Flexio is a fixed FM radio — meaning that AM is not an option — and there is no tuner. You have to buy each station individually. If you have three favorite stations, you’ll have to pick one or buy three Flexios. Also, Flexio does not work when it is out of the broadcasting area. Its designers say, however, that the device could in the foreseeable future receive internet radio via WiFi or WiMax.

The Freeplay Summit Shortwave Solar Radio

If you’re into the conventional radio look, this one’s worth looking into. Freeplay’s Summit Shortwave Solar Radio is a full-featured AM/FM digital radio with built-in rechargeable batteries. Like the FR-150 above, the Summit can be rebooted by the sun or by winding a crank that’s affixed to its side. This solar radio has an alarm clock for weekdays, a snooze setting for weekends and 30 digital presets. It’s nothing fancy. But it does the job of an old-fashioned radio without old-fashioned consumption.