Stately homes on mains supply with extreme outages (8)
I believe the answer is:
mansions
'extreme outages' is the definition.
I can't tell whether this definition defines the answer.
'stately homes on mains supply' is the wordplay.
'stately homes' becomes 'ons' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'on' says to put letters next to each other.
'supply' indicates anagramming the letters (supply of letters to make).
'mains' anagrammed gives 'mansi'.
'ons' put after 'mansi' is 'MANSIONS'.
'with' is the link.
Can you help me to learn more?
(Other definitions for mansions that I've seen before include "Stately homes, chateaux" , "Imposing houses" .)