Fossil-fuel alternative (5)
I believe the answer is:
solar
(Other definitions for solar that I've seen before include "Of the sun, as ray or panel" , "Sort of power" , "Concerning the sun" , "Particular star's" , "Powered by the sun" .)
I believe the answer is:
solar
(Other definitions for solar that I've seen before include "Of the sun, as ray or panel" , "Sort of power" , "Concerning the sun" , "Particular star's" , "Powered by the sun" .)