Designing terawatt scale renewable electricity system: A dynamic analysis for India

Installing multi-terawatt capacities of renewable technologies, mainly wind and solar, could be a potential solution for reducing carbon emissions to reach a safe climate threshold. However, due to variabilities in solar and wind generation, energy storage will play an essential role in the decarbonization of the electrical grid. We examined the implications of adding wind and solar on a terawatt-scale in India's electricity mix and estimated the storage (energy and power capacity) requirements by balancing hourly supply and demand for a 30-year-long-period starting from 2019 until 2048. We used meteorological reanalysis data from MERRA-2 (Modern Era Retrospective-analysis for Research and Application) for hourly wind speed and solar irradiance for the simulation. The results indicated that a solar-dominated capacity mix needed small seasonal storage and required larger storage power capacity to support ‘boost’ charging during the few high sunny hours to meet the demand for many non-sunny hours. Wind-dominated generation depended on large seasonal storage – most charging occurs during monsoon months (July through September) – and discharging in autumn to early winters. The paper discusses the performance of different terawatt scale designs and concludes with their implications for India's energy transition. •Simulated storage sizing for terawatt-scale wind and solar integration in India.•Meteorological reanalysis data covering 39 years for hourly wind speed and solar data.•Storage requirements differ substantially for wind or solar dominated capacity-mix.•Storage reduces curtailment losses, but increases other losses from storage use.•Limited complementary benefits of wind and solar.