Ausgrid has released a new report on its five-year capital works program detailing more than 50 major projects completed in the past two years and more than 80 major projects currently in construction.

The report titled Supply and Demand outlines where Ausgrid is investing or plans to invest to develop and renew its electricity network in Sydney, Central Coast and Hunter. Ausgrid crews have also completed more than 900,000 maintenance tasks in the past two years along with the installation of more than 1,000 street-side substations and about 700 km of 11,000-V overhead and underground cable.

Ausgrid Managing Director George Maltabarow said the maintenance and capital works programs were being driven by a need to replace existing infrastructure.

"This is one of Australia's largest infrastructure programs," Maltabarow said.  "About half of our major zone substations were built in the 1960s and 1970s when the needs of our society were much different to our technology driven world today. This infrastructure must be replaced to ensure we continue to provide a safe and reliable supply of electricity."

Maltabarow said the investment was also being driven by a need to meet increasing peak demand for power.

"Almost 60 percent of homes across our network now have at least one air conditioner," Maltabarow said. "When all these air conditioners are switched on at once there is a high demand on the electricity network. Our specialist crews are focused on providing efficient network services that operate reliably during these peak times."