Such panels have power (5)
I believe the answer is:
solar
'power' is the definition.
(solar power is a kind of power)
'such panels' is the wordplay.
'such' becomes 'so'.
'panels' becomes 'lar' (I can't explain this - if you can you should give a lot more credence to this answer).
'so'+'lar'='SOLAR'
'have' is the link.
Can you help me to learn more?
(Other definitions for solar that I've seen before include "of heavenly body" , "Pertaining to the sun" , "Coming from the sun" , "Particular star's" , "sunny?" .)