What are you using it for?
It's a high-weight hallmark NXT node (raspnxt.hopto.org).
The panel has an output of 3-4W in direct sunlight. That'd be more than enough to run the cubie at full load with full core clock. However, below the panel (in the badass cardboard case I made ) is a 2Ah LiPoly that acts as a buffer. I also use external power from a USB hub now that it's winter, but in summer this should be capable of running autonomously with some more tweaks and lower clocks.