Prominent headline: 'Power Cuts Cut!' (6)
I believe the answer is:
splash
'prominent headline' is the definition.
(I've seen this before)
'power cuts cut' is the wordplay.
'power' becomes 'p' (symbol in physics).
'cuts' indicates putting letters inside (some letters cut their way into other letters).
'cut' becomes 'slash' (slashing is a kind of cutting).
'p' going within 'slash' is 'SPLASH'.
(Other definitions for splash that I've seen before include "Accidentally get liquid on" , "Scatter water about" , "Throw liquid about" , "Excitement" , "Bright patch of colour; cause water to fly" .)