Built in 2008 at a nameplate of 175 tonnes per day, the Kwinana plant will have capacity boosted to 250tpd from April 2020, with plans afoot for another expansion in 2021, to 300tpd.

EVOL LNG has seven mining customers in Western Australia, including Adaman Resources' Kirkalocka gold mine.

According to EVOL LNG manager Nick Rea, fuelling the mine's power station with LNG instead of diesel saves Adaman more than $2 million every  year and helps the company slash its greenhouse gas emissions by a quarter.

Rea said the company's expertise in small-scale LNG and its proven capability to deliver lower cost and cleaner LNG is enabling off-grid mines to move away from diesel.

"We are in advanced negotiations with several parties, and our confidence in future growth prospects has enabled us to commit to the first stage expansion, with front end engineering design underway for the second stage expansion," he said.

"We are fortunate that the Kwinana plant can be expanded with relatively minor investment in a manageable, staged process as demand grows."