Hunter residents are among more than 1000 businesses and 25,000 individuals in NSW who have registered as Earth Hour supporters this year.

Globally, more than a billion people in a 1000 cities are expected to participate.

Under the Hunter Earth Hour banner of "Step It Up" individuals and organisations are asked to turn off all non-essential power in addition to lighting.

Newcastle Lord Mayor John Tate said he was confident the region could build on the achievements of the past two years.

"Last year we turned all the lights off but we realised afterwards that we could have turned a lot more off," he said.

"I think this year is going to be much more effective because people are more conscious of it."

Among the most active participants in the lead-up to Earth Hour were the region's school students.

Dozens of Hunter schools have held trial Earth Hours over the past week in an effort to better understand how their school uses electricity.

"Kids between the ages of 8 and 15 are particularly environmentally aware; they want to do things because these things are not doom and gloom to kids, it's about making a difference," Merewether's Holy Family Primary School principal Mark Twohill said.

"It would surprise me if almost every family in this school doesn't turn off for Earth Hour because their kids will give them such a hard time if they don't."

The region's growing commitment to environmentally sustainable living is reflected in the thousands of individuals who have installed energy-efficient lighting and shower heads in their homes over the past two years.

Together Today, a Hunter-based environmental education coalition, is urging residents to adopt the principles of Earth Hour throughout the year.

"Regardless of which side of the climate change fence you sit on, it makes sense to use energy and water more efficiently," Together Today executive director Chanti Richardson said.

"Long term environmental and economic benefits will only be achieved by sharing the responsibility across the community.

"We all have a role to play and by working together the challenge becomes less daunting."

The power savings achieved during Earth Hour will be reported in Monday's Herald.