NightTec by Unilock is a luminescent concrete paver that draws on solar power during the day and is self illuminating at night. NighTec is inconspicuous during daylight hours but offers additional lighting to hazardous areas during the night.
On the interior of the block luminescent materials 'charges themselves' through 'night lighting crystals' fused in the concrete. No external power or batteries are required. http://www.unilock.com/