The spate of blackouts has affected the Eastney area of the city, Scottish and Southern Electricity Networks (SSEN) has reported.
The outage was first reported at 8.30pm and is expected to last until 11.30pm.
It comes just days after a power cut hit nearby homes in Southsea over the weekend.
In a statement on the latest incident, SSEN said: ‘We’re really sorry for the loss of supply. We currently have a fault affecting the areas listed.
‘If you need more information, please call us on 105 or send us a message on Facebook or Twitter and quote reference JJ8917.’