Country's per-capita consumption of electricity "is way below the global average," Mr Adani said.

The billionaire behind the controversial Carmichael coal mine in Australia is hitting back at criticism the endeavor will be both unprofitable and too dirty.

In an interview in Delhi, Gautam Adani took aim at two major faults opponents have flung at the development: that the mine's low-quality coal won't earn enough money to justify his $2 billion investment, and that the world must abandon the fuel in favor of renewable energy to avoid catastrophic climate change.

"If the project wasn't viable, we wouldn't have pursued it," said Mr Adani, whose net worth of $9.8 billion makes him country's sixth-richest person, according to the Bloomberg Billionaires Index. "Renewable energy is good for the nation, but it can't meet our baseload power needs."

Mr Adani bought the resource in Australia's Galilee Basin in 2010 as companies rushed for overseas energy supplies amid forecasts of booming demand. But as coal prices fizzled through the first half of the decade, Carmichael's output -- closer to lower-quality Indonesian coal than the high-value varieties Australia is known for -- is seen unable to fetch a price strong enough to be profitable.

"The commerciality of Adani's Carmichael mine remains challenging given the significant capital spend and low-quality thermal coal product expected from the mine," said Brent Spalding, a principal analyst at Wood Mackenzie.

Climate Warnings

Australia's Newcastle coal, a benchmark in Asia, would need to rise above $100 a metric ton, from about $78 now, for Carmichael to break even, according to Spalding.

Carmichael, which cleared final state approvals last month, will open up a new mining basin in the Australian outback amid increasingly dire warnings of the need to cut carbon emissions to avoid the ecological and economic havoc of climate change. Though coal is the most carbon-intensive fossil fuel, Gautam Adani has found a relatively friendly host country in Australia, where the economic heft of the resource industry helped re-elect a pro-coal federal government and overcome staunch opposition from environmentalists.

"We entered Australia with two overarching goals; contributing to energy security in India and creating job opportunities for the locals," said Mr , 57, who started as a diamond trader in Mumbai before setting up Adani Group in 1988. His conglomerate -- spanning ports, energy and mining -- has become one of country's key infrastructure service providers, while also venturing overseas.

Surplus Generation

Coal's use has been on the decline in Europe and the US amid cheaper alternatives and pressure to ditch the most-polluting fossil fuel. Yet it dominates power production in much of Asia, a position it's expected to sustain despite a boom in cleaner sources, such as wind and solar, as energy demand continues to grow.

Mr Adani said the board approved 10 million metric tons of annual output from Carmichael's first phase, which will head to his power plants in India, including Mundra and Godda. Adani Group is headquartered in Gujarat.

Country's per-capita consumption of electricity "is way below the global average," Mr Adani said. "India's development is linked to the availability of more power. And coal will play a big role in this as a baseload supplier."

Challenges supplying reliable power to every home have been more about distribution than whether it has enough power plants or coal. The nation already has a surplus of generation capacity, but it's money-losing, debt-saddled state utilities struggle to purchase and distribute enough power, leaving some power stations shuttered and homes in the dark.

When the company decides to raise the capacity of Carmichael -- peak annual capacity is now seen at 27 million tons, down from an original 60 million -- it will explore selling washed coal to buyers in Japan and Korea, according to Mr Adani. Construction has already begun, he said, reiterating the company's two-year timeline for first output.

"The need of the hour," Mr Adani said, "is to get started."