?End of an era?: explosives topple giant chimneys at defunct NSW coal-fired power plant

Explosive engineers have demolished two giant chimney stacks and a boiler at a defunct coal-fired power station west of Sydney as part of efforts to transform the site.

The 175-metre chimneys at Wallerawang have loomed large for residents of Lithgow, a town on the western edge of the Blue Mountains that is home to two coal-fired plants and coalmines.

"It's a really big event up here actually," said Brett Hawkins, chief executive of Greenspot, the company that has taken over the 620-hectare Wallerawang site. "These iconic pieces of infrastructure have dominated the skyline here for decades."

Site managers set up a 500-metre exclusion zone and nearby traffic, including on the Castlereagh Highway, was halted during the morning's explosions. The chimneys and boiler facility collapsed within a matter of seconds.

The plant ceased to operate in 2014 with the loss of 220 jobs, a year after EnergyAustralia bought Wallerawang and the nearby Mt Piper power stations from the NSW government for $160m.

The energy company later sold the site to Greenspot, a private company that hopes to find new uses for Wallerawang's strong grid connections, rail links and proximity to a skilled workforce.

The success of such efforts may form a template for similar power plants elsewhere. For instance, all of NSW's five operating coal-fired power stations are due to close by 2042, with AGL's Liddell plant in the Hunter the first slated for shuttering in 2023.

"We've got our primary focus right now here," Hawkins said before the blast. "But we're certainly believers that there'll be other sites like this."

"They're kind of the fabric of communities as well," he said. "So the challenge is going to be having a whole heap of people working together to tackle the problems that are coming down the line."

Greenspot has been talking to local and state governments about potential support to help transform the site into a mixed industrial, residential and tourism development.

The area includes nearby Lake Wallace, a popular area for campers. It is also close to a site where pioneering scientist Charles Darwin spotted his first platypus during a visit in 1836, apparently contributing to his conception of evolution.

There are significant challenges to deal with. The chimneys and other buildings to be demolished amount to about 25,000 tonnes of concrete alone, that will be crushed and reused.

The two boilers - including one to be demolished early next year - both contain about 18,000 tonnes of scrap metal. All up, the site will produce at least 40,000 tonnes of scrap metal that will be removed and processed for use elsewhere, such as for railway wheels.

Greenspot's Hawkins said the company was close to filing an environment impact statement on plans to develop a giant battery on the site to make use of its strong grid connections.

"We're very close, we believe, to making a pretty significant announcement about who we're going to partner with on that battery," he said, adding the project would require capital investment of $400m.

The cooling tower, with its incredible acoustic properties due to its parabolic shape, will be retained as a possible tourist attraction or for other uses.

Hawkins said the company was confident the Glasgow climate summit this month will add momentum to the transition away from fossil fuels. Greenspot plans to release a "broad-based concept plan" for the Wallerawang site in the first half of 2022.

"We'd like to think we're doing something pretty exciting here to be honest with you," he said. "That we're actually going to make some change, you know, positive change."