[ YOU HEAR BUDDY, THAT'S A SCOFF FROM SNORLAX. WHATEVER. ]

Saur's a plant, so I guess it's energy made from the sun she's taken in? The bigger version of that is called a solar beam, so... [ Makes sense right?? ]

She doesn't need to be in the sun to use it, just be healthy and moving around. But does it work better if she's in the sun - she can charge up much faster, and her hits are stronger too.