Energy company records temperature to inspire one environmentalist (9)
I believe the answer is:
ecologist
'environmentalist' is the definition.
(I've seen this before)
'energy company records temperature to inspire one' is the wordplay.
'energy' becomes 'e' (physics symbol as in E=mci).
'company' becomes 'co' (abbreviation).
'records' indicates a 'sounds like' (homophone) clue (I've seen 'recorded' mean this (as it might sound on a recording)).
'temperature' becomes 'low temperature' (low temperature is a kind of temperature).
'to inspire one' becomes 'gist' (I can't explain this - if you can you should give a lot more credence to this answer).
'low' is a homophone of 'lo'.
'e'+'co'+'lo'+'gist'='ECOLOGIST'
Can you help me to learn more?
(Other definitions for ecologist that I've seen before include "See scientist" , "One concerned with the environment" , "Company's possessions" , "One studying the relation between organisms and their environment" , "Studier of organisms and the environment" .)