This was the second implosion event at the site. The first was in December and that took down two smokestacks.

With the implosion process completed, Duke will be restoring the site, which involves filling, grading and seeding the land.

The company plans to have this finished by mid-2015 and will continue to own and steward the land in the future.

The HF Lee coal plant began operating in 1951 and has been replaced by a 920 megawatt natural gas plant on site that began serving customers in 2012.

“This demolition event is bittersweet, from a historical perspective,” Duke Energy district manager Millie Chalk said.

“It marks the end of a plant that has reliably served the region for more than 60 years, while also symbolising a ‘passing of the torch’ to the new natural gas plant.

“From the environmental perspective the transition is very positive.”

Duke’s investment in five combined-cycle and clean coal plants, including one located at the HF Lee Energy Complex totals $US9 ($A9.5) billion.

Thanks to this investment the company was able to retire seven of its 14 coal plants in the state by the end of 2013.