And PNG's resources of clean coal have yet to be harnessed in a country where only 13% of the population has access to electricity.
The IEA says that while coal still remains the largest source of electricity and the second-largest source of primary energy, the share of coal in primary energy demand and in electricity generation slowly continues to decrease.
Global coal demand grew for a second year in 2018, but its role in the global mix continued to decline, writes Lou Caruana.
Last year's 0.7% increase was slower than the 4.5% annual growth rate seen in the period 2000 to 2010.
Global coal consumption rose 0.7%, or 40 million tonnes, with increases seen only in Asia, particularly in China, India and a few countries in south and south-east Asia.
The Asian growth in demand was primarily because of the increased demand for electricity in these countries, for which coal generally outcompetes natural gas.
In Europe and North America, the decline in coal demand continued, as coal was pushed out by environmental policies, cheaper renewables, and, in the case of the US, abundant natural gas supplies.
In China, coal consumption rose 1% last year, although the strong growth in the power sector was partially offset by a drop in the residential and industrial sectors.
Despite the rapid expansion of non-coal sources of electricity, particularly renewables, coal power generation increased 5.3% in 2018 to meet China's strong power demand growth.
In contrast, coal use in residential and industrial sectors is plummeting, replaced mainly by gas and electricity, owing in part to governmental policies to curb air pollution.