The most common and most likely answer to this crossword clue is the 8 letter word ECOLODGE
I've seen this crossword clue in The Guardian
E
C
O
L
O
D
G
E
Buddy explains!
The straight part
We know that "green hotel" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case green hotel = ecolodge.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 ECOLODGE mean?
ECOLODGE noun- A building designed to house ecotourists, typically built and supported by local labour and with respect for the environment.