To anybody who's been reading the headlines on investment into clean energy production, it's clear that India has been heavily backing solar power. In recent times, the nation has unveiled a string of ambitious solar projects, including the world's first 100 percent solar-powered airport and what is slated to become the world's largest solar power station.

One of the consequences of all this ongoing investment in infrastructure is that the cost of providing solar power in India is becoming increasingly affordable – to the point where the country's energy minister, Piyush Goyal, now says that solar power is a more cost-effective option than the old fossil-fuel staple, coal.

"I think a new coal plant would give you costlier power than a solar plant," Goyal told the media at a press conference in India on Monday. "Of course there are challenges of 24/7 power. We accept all of that – but we have been able to come up with a solar-based long term vision that is not subsidy based."

That vision is part a national plan for to generate more than 100 gigawatts of solar power by 2022 – an ambitious target that's about 20 times beyond the current level solar provides in India.

But what could help make it happen is the falling price of solar power. This year, solar energy prices in the country dropped to around parity with coal for the first time ever, hitting 4.34 rupees (about 6 US cents) a kilowatt-hour (kWh), while coal tariffs range usually range in between 3–5 rupees/kWh (about 5–8 US cents).

And if the price keeps falling at a similar rate, it will soon drop significantly below coal, with some saying that by 2020, solar could be as much as 10 percent cheaper than coal power.

If that does happen, it would be a major turning point in a country where access to electricity is still not universal. Inconsistencies in the country's power grid mean many of India's cities are subject to blackouts and brownouts, and up to a quarter of the population – some 300 million people – have no access to electricity.

Cheaper electricity sourced from the expansion of solar plants across the country could help make for a better, more reliable grid, and one that's less harmful to Indians and the environment at large.

"There are reasons to push solar beyond its low price – it's a much healthier option in a country that is home to 13 of the world's 20 most polluted cities," explains Huizhong Wu at CNN Money. "The environmental benefits of solar will be even more pronounced if its rise comes at the expense of coal, which currently makes up 60 percent of India's energy production. India's coal has a high ash content, and it releases toxins and metals into the air when burned."

Let's hope this momentum behind solar keeps up in India, and that reliance on coal can be reduced as soon as possible. It's the only way to go.