India has some huge renewable energy goals. But can they be achieved?

One of the largest countries on the planet by area, India is home to more than a billion people, a vast economy and a huge military. 

The country's energy needs are similarly large scale: India's primary energy consumption hit 809.2 million tons of oil equivalent in 2018, according to BP's Statistical Review of World Energy. On this metric, the country is behind only China and the U.S.

When it comes to renewables, India has set itself some ambitious targets. Prime Minister Narendra Modi's government is targeting 175 gigawatts (GW) of renewable capacity by the year 2022 — a goal proudly displayed on the Ministry of New and Renewable Energy's website — and is aiming for 450 GW by 2030. Capacity refers to the maximum amount that installations can produce, not what they are currently generating.

To put all of the above in perspective, India's installed capacity — for all energy sources — was a little under 369 GW at the end of January 2020, according to government figures. Breaking the numbers down, renewables — listed as small hydro, wind, solar and bio-power — accounted for over 86.3 GW of this total.

At the moment, meeting the 2022 target could be a tricky proposition.

Tim Buckley, from the Institute for Energy Economics and Financial Analysis (IEEFA), told CNBC via email that "lost momentum over the last 18 months" in renewable energy investing probably meant that the 2022 target was "now out of reach."

"India has seen too much policy inconsistency and change, as well as state-centre conflicts, plus the drag of national policy objective contradictions," Buckley, who is director of Energy Finance Studies for South Asia at IEEFA, added.

One example Buckley listed was the country's goal to accelerate "low cost" renewable energy installations "whilst at the same time raising costs by the imposition of import duties in order to underpin the Make in India manufacturing strategy."

Ajay Shankar, a distinguished fellow at The Energy and Resources Institute (TERI), explained to CNBC via email that increasing India's current renewable capacity from around 86 GW to 175 GW by 2022 was "clearly challenging."

"However, India's achievements in the last decade in accelerating renewable capacity addition have been remarkable," Shankar — who was expressing his personal views — added, claiming that the country had "surprised both itself and the world."

"Starting with less than 1 GW of solar power capacity in 2010, it now has around 34 GW of solar power," Shankar said. "India has also added about 25 GW of wind power capacity in this period."

He did note, however, that a "very rapid scaling up of renewable capacity addition" would be required to achieve the 2022 goal.

India's longer term renewables target of 450 GW represents a big challenge that will dramatically alter the country's energy landscape.

It can be viewed through the prism of the "global energy transition," which refers to a move away from fossil fuels and toward renewable sources of energy.

The impact of this shift could be significant: research and consultancy group Wood Mackenzie has previously said that "close to 20% of global power needs will be met by solar or wind" by the year 2035.

"The Government of India has set a very ambitious 2030 target of 450 GW of renewable energy … or 520 GW including large scale hydro," the IEEFA's Buckley explained.

"IEEFA views this as aggressive but achievable, subject to the government delivering policy stability, transparency and consistency," Buckley added.

While sources such as solar and wind may be renewable, they do not promise a constant and predictable stream of power: the sun does not always shine and the wind does not always blow.

Given this fact, if renewables are to become a crucial part of India's energy mix, energy storage will be incredibly important.

Ajay Shankar explained to CNBC that the "key issue for India" and the rest of the world was costs related to electricity storage.

"These have been declining rapidly," he noted. "The expectation is that they continue to fall quickly. India is taking the first steps towards deploying storage technologies and getting experience of managing the system."

When costs of storage had declined sufficiently, Shankar said large scale deployment would be feasible. "The use of fossil fuels would then start declining," he said.