More than 6,000 homes have been left without power in the Chichester area.
The power cut started at 9.50am today (Tuesday, March 27) because a fault in an underground cable.
The areas affected are Goodwood, Maudlin, Tangmere, Westerton and Westhampnett.
A spokeswoman for Southern Electric said power should be restored by this evening.
“We have arranged for generators to restore the supply,” she said.
“They are expected to be restored by about 7pm to 8pm.”
She said work would continue to fix the cable.
She added: “Southern Electric would like to apologise to all customers involved.”