About 400 households found themselves without electricity due to a faulty transformer at a substation.
The transformer at the Fairfax Drive substation, in Westcliff, failed at 11.32pm on Sunday and electricity was not restored until an hour later.
While EDF Energy Network engineers worked on the problem, firefighters were on standby.
Paul Copeland, sub officer at Southend Fire Station, said: "We stayed until the electricity board had sorted it out. There wasn't a lot of damage.
"It had just given up the ghost and there was quite a bit of smoke. Quite a few homes were in the dark as well as a factory block."
A spokeswoman for EDF Energy Network apologised for the power cut.
She said: "EDF Energy Networks engineers worked to restore power as quickly as possible and all customers went back on supply at 12.30am today.
"We apologise for any inconvenience this may have caused."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article