Increased consumption, more customers and the sale of its headquarters in Dickson for $17.5 million in September last year led to a successful year for the gas and electricity provider, which is 50 per cent owned by Actew Corporation. AGL Energy owns half of the company's retail business and Jemena Networks owns half of ActewAGL's energy distribution business.

Actew is wholly owned by the ACT Government, and according to its annual report it received $80 million of ActewAGL's $117.5 million returns to its joint venture partners, up $11 million from 2007-08.

ActewAGL chairman John Mackay said in his company's annual report, ''We were able to achieve this because of continued efforts at cost control, coupled with growth in customer numbers.''

ActewAGL also declared record revenue of $788.4 million, up from $717.1 million the previous year, thanks to price rises for electricity and gas, the sale of ActewAGL House, higher consumption as a result of Canberra's population growth, cooler winter temperatures and increased consumption by its commercial customers.

ActewAGL will be moving to its new leased headquarters at the former Greater Union cinema site, on the corner of Mort and Bunda streets, in June next year.

The report also said ActewAGL planned a record capital works program, including $400 million for its energy networks over the next five years and helping Actew implement $600 million worth of projects in the same period.

Among the capital works is construction of a $24 million substation in the East Lake precinct.

According to an application notice for the substation, a development application will be lodged with the ACT Planning and Land Authority later this year and the station is expected to be operational by late 2012.

The application notice said an upgrade of the existing network in Canberra's south - consisting of Telopea Park zone substation, Causeway switching station and Fyshwick zone substation - was needed urgently because the existing network would run out of capacity within two years.

''Based on information of the known current and future development in the short term and long term, it is anticipated that the demand in south Canberra will exceed the present zone substations' capacity by 2011,'' the application notice said.

In particular, major developments in the Canberra Airport precinct, the Australian Federal Police facility at Majura and retail outlets in Fyshwick would put pressure on the existing network.