Kyocera's solar smartphone concept is a hot idea (pictures)

BARCELONA -- At MWC this year, Kyocera showed off some of its early prototype and concept devices, some of which help users survive emergency and extreme situations, while others have innovative power sources.

One such idea was a phone with a 0.6mm-thick solar film embedded in the back of the handset's display, so you can charge your device when the sun is shining.

The solar capability is meant as a supplemental charging method, instead of a primary one.

Due to its current inefficiencies, however -- the model requires 2 hours of charging to give you an extra 5 minutes of talk time -- Kyocera won't be ready to release a working solar-charging handset until it can boost its performance.

Another idea the company envisioned was a line of durable handsets that you can customize according to your needs. All phones will have a rugged "core" platform, that can then have different degrees of ruggedness.

One option is slightly rugged, thin, and still consumer friendly.

Others include a very rugged model that can survive cold temperatures and has an extra antenna. Another is this extremely rugged phone, with dual speakers and bumpers that protect the corners.