Solar power potential in India has decreased over last three decades: Study
The study was conducted by scientists from the India Meteorological Department (IMD) Pune, including B L Sudeepkumar; Ranjan Phukan; Raja Boragapu; C B Nalage; A D Thathe; and K S Hosalikar, head of climate research and services
A recent study has highlighted that with a decreased trend in solar radiations over most of the country, the solar power potential in India has decreased over the last three decades. Published in the Mausam Journal in the second week of April, the study also highlighted that there is a need for wide use of solar panels with better efficiency to meet the energy requirements from solar resources.
The study was conducted by scientists from the India Meteorological Department (IMD) Pune, including B L Sudeepkumar; Ranjan Phukan; Raja Boragapu; C B Nalage; A D Thathe; and K S Hosalikar, head of climate research and services. The scientists investigated the climatology and global radiation (GR) trends, diffuse radiation (DR), bright sunshine hours (BHS), and technical potential of solar power (solar photovoltaic potential/SPV) using in-situ data procured from the IMD between 1985 and 2019. The data revealed that GR is high over the northwest and inland areas of peninsular (extreme north and northeast) India whereas DR is high over coastal stations, including the extreme northern parts of the country. BHS is more over the northwest region that includes the north, northeast and southern peninsular India.
The country has a SPV in the range of 1800 to 3400 Wm-2 with substantial regional variations. The GR and BHS have a significant decreasing trend in most parts of the country. The technical potential of solar power has a significant decreasing trend in most of the selected stations, which is alarming. It necessitates the wide use of solar panels with better efficiency to meet the energy requirements from solar resources.
Speaking about the key findings of the study, B L Sudeepkumar said, “The country is experiencing a widespread decreasing trend in solar radiation. This can be attributed to air pollution and increased clouding. As solar radiation intensity has been decreasing and there are indications that this trend is going to continue in the upcoming years, too, it is necessary that we, especially the solar panel industry, adopts technology that is more efficient in providing higher energy from solar resources.’’
Solar energy has been recognised as an alternative to conventional energy resources. Among all the clean technologies, solar energy serves as an effective renewable energy resource to mitigate greenhouse gas emissions and reduce global warming. Further, solar energy is one of the resources capable of self-reliant energy generation, reducing foreign energy dependence. In tropical countries like India, solar energy has immense potential. The energy of about 5,000 trillion kWh per year is incident over India’s land area with most parts receiving 4 to 7 kWh m-2 per day. India has already identified its potential and become one of the forerunners in the renewable energy markets around the world. India’s Intended Nationally Determined Contributions (INDCs) target is to achieve about 40% cumulative electric power installed capacity from renewable energy resources and reduce emission intensity by 33 to 35% by 2030.
Significant observations
The study highlighted that there is a significant decrease in GR in New Delhi, Shillong, Ahmedabad, Kolkata, Nagpur, Mumbai, Pune, Vishakhapatnam, Goa, Chennai and Thiruvananthapuram. Among these stations, the maximum decrease is observed over New Delhi (0.7%) while the minimum decrease is observed over Pune (0.1%).
The trend of annual DR shows an increase in more than 80% of the stations, out of which nearly 60% exhibit a statistically significant increasing trend. The increasing trend in DR is attributed to an increase in atmospheric turbidity and cloudiness over the region.
The trend in annual BHS shows a decreasing trend over the stations except for Nagpur, where there is an increasing trend but statistically not significant. However, a significant decreasing trend (at 0.05 level) is seen over New Delhi, Shillong, Ahmedabad, Mumbai, Pune, Vishakhapatnam, Goa, Chennai and Thiruvananthapuram, which is due to an increase in atmospheric turbidity and cloudiness over the region.
In line with the trends in GR and BHS, the SPV also exhibits significant decreasing trends (at 0.05 level) in all the stations except Nagpur and Kolkata, where the decreasing trends are statistically not significant.