The reason for asking the question is obvious. If coal demand in one-time boom markets such as China is weakening, then a surge in demand for imported coal from India will be the perfect tonic for Australian coal exporters.

The problem is how to know, with any degree of comfort, exactly what’s happening in India – a country with a big domestic coal industry, but also a country which has repeatedly disappointed with promises to boost domestic coal production.

This time, according to the new Indian government led by gung ho Prime Minister, Narendra Modi, it will be different with the government-controlled Coal India given the job of boosting production to one billion tonnes by 2020.

If the grossly-inefficient organisation performs as it has in the past then that one billion tonne target will never be met, and certainly not by 2020 as that will require output to effectively double in five years.

What seems more likely to happen is that India will struggle to provide enough domestically-mined coal to keep pace with an ambitious coal-fired power-station building program which is seen as a key element in Modi’s modernisation plans for India.

Two numbers from a recent report into India’s thermal coal market by Australian investment bank Macquarie highlight the challenge.

Over the past five years production by Coal India has risen at a compound annual growth rate (CAGR) of 2%. Over the same time coal-fired power generation has risen at a CAGR of 9%.

You do not require a degree in mathematics to recognise that when those two CAGR growth rates are stretched over a five years period the amount of coal being produced rises by around 11%, while the amount of coal-fired electricity increases by around 60%.

Different numbers can be produced by inserting different assumed growth rates for coal and electricity, but the key to everything is whether this time Coal India will perform as promised or whether Modi’s demand for greater electricity production is satisfied by importing more coal.

Macquarie reckons there is a greater chance of Coal India, and other coal miners in the country, disappointing as they have done so often in the past which is why it used an old proverb to kick off its research report: “Fool me once, shame on you. Fool me twice, shame on me”

As with the compound interest example no-one should need an explanation of the saying because it is simply pointing out that Coal India has misled its customers before, and it is wise to assume that it will do it again – so more fool you if you’re not expecting it.

What the investment bank has done in its Indian coal research is run a series of examples based on assumptions about domestic coal supply and electricity demand to arrive at a conclusion that while India is trying hard to get its coal-act together it is more likely to disappoint again, which could be good news for international coal miners.

In fact, if Indian coal production continues to disappoint it will not be long before India overtakes China as the world’s major coal importer.

“Indian seaborne thermal coal imports have grown more strongly than those of any other country over the past decade, at a 26% CAGR,” Macquarie said.

The compound annual growth rate has been so strong that it implies a doubling in imports every three years and could mean that India will soon overtake China as the world’s largest seaborne coal importer, according to the bank.

“The reason for this surge is weak domestic coal production growth combined with strong power sector demand growth that has led to a widening supply gap,” Macquarie said.

“It has been our base case that this will continue to widen over the next five years, on the assumption that Indian production growth continues to disappoint.”

However, to test its own hypothesis given the election of the growth-focused Modi government, Macquarie gave Coal India the benefit of a few doubts to see if it could rise to the occasion and meet electricity demand from its own mines.

Macquarie’s answer to the question is no. India is unlikely to satisfy coal demand from its own resources.

“We forecast that Indian seaborne thermal coal imports will grow at 7% (CAGR) from 2014. This means that annual Indian imports will have risen by 60 million tonnes,” it said.

The bank acknowledges that it could be misreading the forecasts in its crystal ball and that India could do the job, but if that’s to happen then huge investment will be required in railway systems and other infrastructure – a task that will not be easy in a country of 1.3 billion people.