Adapting to High Solar Penetrations in India: Learning from International Experiences and Planning for Grid Stability

As India embarks on a remarkable transformation of its power system in the coming decade, the government aims to increase renewable generating capacity from 175 GW in 2022 to 450 GW in 2030. This ambitious goal has raised concerns among some state leaders who anticipate challenges such as excess variable renewable energy (VRE) generation, increased power exports to other states, displacement of coal power plants, and potential curtailment of solar and wind power to ensure system security.

Recent trends in renewables integration have brought about challenges such as increased hourly demand variability, ramping requirements due to solar impact on net demand, short-term frequency variations, and local voltage issues. Although India’s national-level inertia has experienced only a slight decline since 2014, it is essential to monitor local system strength and inertia requirements as states with high renewable energy penetration may face system inertia challenges in the future.

To maximize the value of solar and wind power, Indian states should leverage all potential sources of power system flexibility, including demand-side flexibility, power plant flexibility, storage (pumped-storage hydro and batteries), and grid flexibility. Additionally, policy, market, and regulatory solutions can be implemented in the short to medium term until 2030. The optimal mix of flexibility resources should be determined for each state, considering the regional and national context.

One significant area of focus is policy and tariff reforms that can tap into the demand response potential. As the electricity demand undergoes a transformation in India, sectors such as agriculture, buildings, and industry will play a more active role in balancing power supply and demand. The existing agricultural demand shift from high to low demand hours already provides low-cost power system flexibility in India. In the future, transitioning from involuntary agricultural demand shift to proactive agricultural demand response can be one of the most cost-effective solutions to improve power system flexibility, but it must be balanced against the potential impact on water stress in each region.

Drawing from international experiences, such as the California duck curve, this blog post discusses the implications of high solar penetration in India and possible strategies to ensure grid stability.

Implications of High Solar Penetration in India: As India increases its solar power capacity, the country’s load curve could be significantly impacted. At ultra-high PV penetrations (>50% on an annual basis), longer-term mismatches between energy supply and demand might arise, driving down PV economics. Moreover, shifting energy supplies over days, weeks, or even months might be necessary, depending on the region.

Planning with International Experiences: India can learn from international experiences, such as the California duck curve, to plan for grid stability amidst high solar penetrations. Here are some strategies to address the challenges posed by high solar penetration:

1. Energy Storage: Deploying energy storage systems, like batteries, pumped hydro, and compressed air energy storage, can help balance the grid by absorbing excess solar generation during peak hours and releasing it during periods of high demand.
2. Demand Response Programs: Implementing demand response programs encourages consumers to shift their electricity usage to off-peak hours, alleviating pressure on the grid during high-demand periods.
3. Flexible Generation Sources: Developing and deploying flexible generation sources, such as natural gas-fired power plants, can help balance the grid by rapidly ramping up or down to accommodate fluctuations in supply and demand.
4. Grid Interconnections: Expanding grid interconnections with neighboring regions can facilitate the sharing of renewable energy resources, allowing for a more diverse and stable energy mix across a broader geographic area.
5. Seasonal Storage and Solar Fuels Production: Developing advanced conventional longer-duration storage technologies and solar fuels production can address seasonal mismatches. Solar fuels production enables economy-wide decarbonization by providing transportation fuels, space and process heating, and chemical feedstocks.
6. Overbuilding and Curtailment: Ultra-low-cost PV potentially allows for overbuilding, generating greater production during peak seasonal periods while accepting cost-effective curtailment. This strategy can help address the seasonal mismatch in energy supply and demand.

Conclusion: India can draw valuable lessons from international experiences, such as the California duck curve, to ensure grid stability as solar power adoption grows. By implementing a combination of energy storage, demand response programs, flexible generation sources, grid interconnections, seasonal storage, and overbuilding strategies, India can achieve its renewable energy targets while maintaining grid stability and reliability.