Warming Indian Ocean deflates wind power in India
doi:10.1038/nindia.2019.15 Published online 13 February 2019
India’s wind energy potential has been consistently declining for the past four decades due to a warmer Indian Ocean, new research reveals1.
A research group from Harvard University in the US found in 2017 that wind energy has been rapidly declining in China for the past 37 years. Following this study, the group wanted to explore the wind power potential in India.
Along with Pekin University researchers, they found that western India accounted for the largest share of wind power (36 per cent), followed by northern (26 per cent) and southern (25 per cent) India. Interestingly, upon mapping the trend in wind power for the last four decades (1980–2016), they found that the decline in wind power has also been the greatest for western India, which has seen a consistent drop by five per cent every decade.
Overall, they measured the the wind energy potential to have declined by 13 per cent from 1980 to 2016. They say this suggests that wind power systems installed during this time may have become less productive.
India is the third largest energy-consuming country in the world. The country’s energy consumption is expected to quadruple by 2040. Although the wind capacity was only six gigawatt (GW) in 2006, it has increased more than five times to 32 GW in 2017. TheIndian government has set an ambitious target of doubling it to 60 GW by 2022.
“We have pointed the regions with large negative impacts from climate change, and regions with less impact”, Gao Meng, first author of the study told Nature India. “Although similar declines are found for both China and India, the reasons or conditions are totally different. The decline in India is contributed by summer monsoon, while in China it is mostly due to the winter monsoon.”
The Indian summer monsoon is driven by pressure differences generated due to high temperature in the Indian subcontinent and low temperature over the Indian Ocean. Meng and co-researchers show that this pressure gradient between the land and the sea also determines the wind energy potential in India.
Although the land temperature has remained consistent since 1980, equatorial and southern Indian Ocean has become significantly warmer. This has led to less intense Indian summer monsoons and declining wind speeds, especially in western India.
“The science behind the warming of Indian Ocean is not very clear yet”, Meng said. Apart from the green-house gases (GHGs) generated by human activity, the climate in the Pacific Ocean could also contribute to the warming of the Indian Ocean, he said.
Meng suggests that investing in wind turbines in regions less influenced by this phenomenon would be a good idea. Another way to work around this would be to use technology that can harvest wind potential even at varied wind speeds, says T V Ramachandra, a scientist at the Centre for Ecological Sciences at Indian Institute of Science , Bangalore.
1. Gao, M. et al. Secular decrease of wind power potential in India associated with warming in the Indian Ocean. Sci. Adv. 4: eaat5256 (2018) doi: 10.1126/sciadv.aat5256