Energy storage is essential for the diurnal balancing of variable renewable energy (RE) generation and avoiding the build-out of new thermal capacity required primarily for meeting peak load.” – Lawrence Berkeley National Laboratory report

The Indian electricity system is undergoing a rapid transition towards clean energy sources, primarily renewables, to meet the growing energy demand and reduce carbon emissions. However, the integration of large-scale renewable energy sources such as solar and wind into the grid presents a significant challenge due to their inherent variability. This challenge has created a pressing need for energy storage systems that can store excess renewable energy during times of low demand and release it during peak demand hours.

According to a report by Lawrence Berkeley National Laboratory (LBNL), energy storage is essential for the diurnal balancing of variable renewable energy (RE) generation and avoiding the build-out of new thermal capacity required primarily for meeting peak load. The report highlights the need for about 60 GW (250 GWh) of energy storage to meet morning and evening peak loads by FY 2030. This storage capacity would help reduce the ramping stress on thermal plants and provide critical flexibility in states with high solar deployment and low hydro resources such as Rajasthan and Gujarat.

The report further shows that a shift of 60 GW of load (50 GW of agricultural load and 10 GW of heavy industrial load) to solar hours by FY 2030 would optimally balance the load curves for May and October. States like Karnataka, Gujarat, and Maharashtra have already shifted significant agricultural load to daytime, and several other states are following suit. On average, such a shift would reduce the nighttime load by 30 GW nationally.

The report also provides insights into the charging and discharging hours for batteries for an average day during four months of the year in 2030. The batteries would typically charge during the day and discharge over 6-8 hours during the morning and evening peak hours. During winter months between October and January, batteries would also charge at night due to the steep reduction in wind generation during winter.

The report emphasizes the importance of fast-responding batteries to meet the grid’s morning and evening ramp requirements in 2030. These ramps are timed with the large on-ramp of solar generation between 7 and 8 am and off-ramp around 6 pm. The optimal battery storage requirement in the intermediate years between 2020 and 2030 is shown in Table 4 of the report, which ranges from 12 GW/48 GWh in 2025 to 63 GW/252 GWh in 2030.

The LBNL report highlights the critical role of energy storage in the Indian electricity system’s transition to clean energy sources. The report’s findings underscore the need for a significant increase in energy storage capacity to meet the growing energy demand and balance the diurnal variability of renewable energy sources. The deployment of energy storage systems would also help reduce the ramping stress on thermal plants and provide critical flexibility in states with high solar deployment and low hydro resources.