The most common and most likely answer to this crossword clue is the 9 letter word WINDPOWER
I've seen this crossword clue in The Daily Telegraph
W
I
N
D
P
O
W
E
R
Buddy explains!
The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does WINDPOWER mean?
WINDPOWER noun- Power harnessed or generated from the wind