Increasing share of renewables in grid electricity and its implications on grid stability

The recently released IRENA renewables statistics 2021 report highlights that the global RE capacity has reached over 2500 GW, and in year 2020, the capacity addition was of the order of 280 GW, though much of this capacity has come up from China, US, and INdia..India added about 13.8 GW of RE capacity during the same period, and much of this capacity has come up from the solar and wind installations. Of the  new capacity additions, RE contribute to over 80% of the total new capacity added in the grid. In Indian context the GOI is planning to achieve 50% of grid electricity mix from renewables by 2030.

WIth increasing share of renewables in grid, the grid stability has become a major challenge to the power system operators globally, and the situation is nothing different in India. As we add more and more RE capacity in grid, the challenges of grid flexibility become a concern, and there is a need to take immediate steps through addition of utility scale energy storage systems in the grid, which will account for additional expenses to bring system flexibility. The intermittency of solar and wind power account for complexity in power system operations. Already the day peak is shifting towards the evening and the off peak hours in the grid in night are also shifting in the day peak when it merges with the larges share of solar capacity. In order to balance the demand supply, there is also need to correct the situation through introducing the time of day tariff to larger section of consumers.

The increasing share of RE capacity in India has also led to curtailment issues and loss of generation to many developers. Many solar and wind generators are now pushing the government to account the losses due to curtailment in the upcoming PPAs. The increasing share of RE will lead to variability in the grid, which can be addressed through better interconnections between the supply centers and demand centers. There is a need to introduce the system operation costs in the tariff components of RE PPAs, which will reflect the true cost of renewables.