Energy type (5)
'energy type' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for solar that I've seen before include "Particular star's" , "Of the sun, as ray or panel" , "room" , "Sun-powered" , "Concerning the sun" .)
(Other definitions for electricity that I've seen before include "Source of light and power" , "Current supplier" , "Energy associated with charged particles" , "Domestic energy supply" , "One form of energy" .)