Coal has begun leaving the controversial Maules Creek mine in northern NSW, and the operator expects costs at the mine will be lower than originally expected.
The first trainload of coal left for the port at Newcastle , four months after mining began, Whitehaven Coal said.
That's despite ongoing protest action against the mine's development, which included the arrest of several protesters on Monday for climbing onto a train being loaded with coal.
Rugby union Wallaby David Pocock was also charged earlier this month after chaining himself to machinery at the mine site.
The beginning of construction work of Maules Creek, north east of Boggabri was held up by legal challenges to government approvals, but since getting underway in December 2013 the project has proceeded ahead of Whitehaven's schedule, and $767 million budget.
"Railing first coal less than a year from when construction started is a fantastic outcome and I congratulate all those involved in this very successful project," Whitehaven chief executive Paul Flynn said.
The company originally expected to begin transporting coal in March 2015, and that was recently revised to January.
It has also downgraded its expected operating costs for the first full year of production at Maules Creek, which are now estimated to be $62 per tonne of coal, excluding royalties.
That is down from earlier estimates, which as recently as May were $67 per tonne.
Costs in the first five years of operation are expected to be between $63 and $64 per tonne.
Whitehaven shares have been hit hard in recent months due to falling commodity prices.
The mine will produce about 2.5 million tonnes of coal before June 30, 2015, and about six million tonnes of coal in its first full year of operation.
Mr Flynn said Maules Creek was already having a substantial positive economic impact on local towns, and will have 450 full time workers once fully operational.