You guys are right, far too much guessing. Sometimes it is best to just quit! I always rate logical puzzles with 5 stars, this doesn't get a rate at all from me. Sorry author Fiona, Not my cup of tea :(
The 5 small bolts are little "stair" formations made out of 6 boxes each. They all go from the upper right to lower left, as stated by Joe. The bolts start at: r2/c22 (part of the "3") r3/c6 r11/c5 and c19 r14/c23
Along with Teesea's hint with the bigger bolt, it should now be possible to solve it.
SPOILER: All lightnings go from upper right to lower left. (It remains little ambiguous, however "guessable"...)
Thanks to Teesea and Joe Tramp for the hints! On the last part of the puzzle, make sure the top-left mini-lightning doesn't touch the cloud.
r2/c22 (part of the "3")
r3/c6
r11/c5 and c19
r14/c23
Along with Teesea's hint with the bigger bolt, it should now be possible to solve it.