Green supporter, conserving energy, showing bit of backbone? (8)
I believe the answer is:
vertebra
'bit of backbone?' is the definition.
('vertebra' is part of 'backbone')
'green supporter conserving energy' is the wordplay.
'green' becomes 'vert' (I've seen this before**).
'supporter' becomes 'bra' (I've seen this before).
'conserving' indicates putting letters inside.
'energy' becomes 'e' (physics symbol as in E=mce).
'vert'+'bra'='vertbra'
'vertbra' placed around 'e' is 'VERTEBRA'.
'showing' acts as a link.
(Other definitions for vertebra that I've seen before include "bit of backbone" , "One of the small bones of the backbone" , "Part of the spine" , "Segment of the spinal column" , "Joint" .)