A single solar cell on an electronic ink advertising panels being developed by Neoluxiim, a Korean company, will charge themselves by using soar power obtained from commercial-grade indoor lighting. The single cell panel could power the the advertising display for up to eighteen months of continuous use. The display itself would include a small processor and support rotating display images and text.

A solar powered electronic paper 
advertising display (Source: Neoluxiim)

These new panels are self-contained units with everything needed to power, program, and run the display included within the unit itself. The units are more compact than those requiring battery power or electrical plugs. The units will also be more portable and can be used in many more locations than those requiring external power.

[Source: The Future of Things]