The plant has been closed since Saturday night when it ran out of fuel, said Ahmed Abu Al-Amreen, an official in the energy ministry.
Parts of the strip have been without power for 20 hours a day, the United Nations said, up from 12 hours previously.
The Palestinian Authority in Ramallah has gradually removed a tax exemption on fuel since January, demanding Hamas pay taxes on imports to besieged Gaza.
Relations between Islamist movement Hamas and the PA, which is dominated by bitter rivals Fatah, are fraught.
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The rest of Gaza's energy needs are imported from Israel and Egypt.
The power station was closed down in July 2015 in similar circumstances.
It was damaged by shelling more than once during the 2014 war between Israel and Palestinian militants in Gaza.
Some 1.8 million people live in Gaza, which has been under an Israeli blockade since 2006.