Lawyers for Binyam Mohamed face the incredible prospect of a six-month jail sentence in America after writing a letter to President Obama detailing their client's allegations of torture by U.S. agents.

The NSW Government has called an urgent meeting with an energy company after a second major power outage hit Sydney's CBD in less than a week, with an angry premier declaring ``it's not good enough''.

Power company EnergyAustralia has apologised for the second major disruption to Sydney's power supply this week, which affected about 50,000 homes and businesses.

Properties in the northern part of the city, along with parts of eastern and inner city suburbs, were blacked out at 10.28am on Saturday.