Solar PV Concentration In Few States Not Healthy, Hints IIT Study

A latest study undertaken by the researchers at the Indian Institute of Technology (IIT), Kharagpur, hinted that the current trend of concentration of solar power projects in certain Indian states was good for the growth of the sector.

The report, co-authored by Saikat Ghosh, Jatindra Nath Roy and Chandan Chakraborty, analyzed the merits of geographical diversification of solar PV power plants for a resilient PV-dominated electricity grid in India. The report said that around nine Indian states alone share 90.64 percent of total PV capacity in India. 

However, the IIT report said that large-scale dispersed PV generation could significantly reduce the risks associated with low PV generation and high variability in a future PV-dominated grid. 

“The novelty of this study lies in demonstrating the benefits of combining multiple PV sites in various regions to mitigate the risks of low PV generation and high variability. The variability of individual sites was found to be up to ∼3.5 times higher than the variability of combined generation,” the report said.

“It is found that even during the peak noon hour in high irradiance and major solar park sites, the PV generation can drop in the range of 0–10% of the DC rated capacity, especially during the rainy season or due to cyclones. However, it is shown that there is scope to reduce the variability, intermittency and risk of low PV generation by diversifying solar parks in geographical regions…This would ensure high reliability and resilience of the future PV-dominated grid,” the report by the researchers from IIT Kharagpur said. 

It also observed that the deployment of PV in southern parts of the country could reduce the seasonal variation in PV generation and increase PV generation hours in the context of the national grid. 

“Deploying more PV in the eastern region of the country, where PV penetration is abysmally low compared with the western part, can further increase PV generation hours, as there is a difference of ∼2 hours in the sunrise/sunset times between the eastern and western regions of India,” the report said. 

The report also batted for boosting solar projects in the northeastern Indian states and using the facilities of existing hydro transmission lines to increase the Capacity Utilization Factor (CUF).

“The north-eastern region of India has high hydroelectric potential, but hydroelectric plants are mostly used to meet peak demand during evening hours when PV power is retired and ramping needs are high, resulting in a low CUF for transmission lines. This paper discusses that by installing PV generation in the northeast, the same transmission lines can also be used to transmit solar electricity during the day, thus increasing its CUF. In addition, other benefits of PV power combined with hydroelectric power have been discussed,” the report said.

The report also batted for boosting solar PV in regions like Ladakh due to its highest capacity factory or specific yield for PV generation, mainly due to high solar resources and low temperatures. It also recommended using agro voltaic in regions in agriculture-dominated states where cheap and barren land for PV deployment is tougher to find. 

The findings are intuitively logical too, as the whole advantage of having a country with the spread of India is that solar generation can be spread out more widely and over a longer duration by siting it over all parts. Be it rooftop solar for local use of utility scale solar for grid supplies it is important that  solar spread happens more widely in the country.