The old New Plymouth power station site is being sold to Contact Energy and Methanex New Zealand in a $24 million deal.
Contact Energy closed the gas and oil-fired station five years ago when asbestos was discovered at the site.
Port Taranaki plans to expand its operations on to most of the 21 hectare property, while Methanex New Zealand is buying the section of land where its two storage tanks are located.
The site is adjacent to Port Taranaki-owned land and chief executive Roy Weaver says tanks, pipelines and storage buildings will be put on it.
Most of the existing buildings are likely to be demolished, he says, though the massive chimney will remain.
Contact Energy has the option of buying back part of the site should it need it for future power generation.