Please implement the suggestions from the [chat] below and update the [draft]:

[chat]:
I have looked at the draft - it looks good. I want to talk to you briefly about System adequacy part being removed - since it has the specifics on grid-strength, and other aspects that Grid-India cares about. 
 
other than that, everything is integrated
 
Section 5 reviison looks great.
 
Vivek reviewed the adequacy section, and his response was "this is not our scope". If there are elements you still want to include they should be integrated into the other sections. 
 


[draft]:
Technical challenges surrounding IBR integration come in many forms that span a wide range of temporal and scales and involve many aspects of grid planning and operation. Here we organize the discussion of those challenges and their solutions around time scales for which actions are taken, spanning from long-term planning to short-term stability. Components of this discussion are, in practice, highly interrelated with significant overlap across challenges and solutions. This structure is largely intended to highlight clear, actionable strategies for successful IBR integration.
4.1	Flexibility
Grid flexibility refers to the ability to respond to variability in electricity production and consumption swiftly and efficiently, typically in the context of 5-min to 1-hour time scales. Inverter-based resources (IBRs) like PV and battery storage introduce new forms of variability that must be balanced across multiple timescales \cite{clade_flexibility_2021}. Sufficient flexibility has traditionally been achieved with dispatchable thermal generators that can ramp output up or down as needed to balance energy supply and demand. However, as their share of the generation mix declines, alternative sources of flexibility are required to balance the growing share of variable renewables \cite{denholm_flexibility_2016}. The effective use of IBRs for grid flexibility is an emerging industry practice. For example, power electronics can help PV provide some flexibility. Battery storage is typically even more flexible than thermal generators but must be operated within energy storage capacity constraints, cycling limits, and competing uses for ancillary services. 
The roadmap activities outlined in this section are intended to achieve several outcomes:
•	Determining the need for emerging flexibility services through expanded and new ancillary service markets. 
•	Identifying technologies and operating strategies for providing flexibility services in a high-renewable, high-IBR system. 
•	Enabling emerging IBR technologies to fully participate and provide grid flexibility. 
Activities
The following activities utilize these approaches to maintain and improve grid flexibility in a future where IBRs provide a strong contribution to overall grid energy balancing and ancillary services.
1.	Establish forward-looking requirements for system inertia and identify assets that could perform synchronous condensing. Assess the need for inertia and fast frequency response in the system. Explore options like retrofitting existing generators for synchronous condenser mode, installing new synchronous condensers, or utilizing advanced IBR controls to emulate inertia.
Example:  Conduct studies to determine minimum inertia requirements and identify potential sites for installing synchronous condensers or deploying grid-forming inverters.
2.	Assess the impact of storage technologies on net load ramping requirements. Analyze how energy storage systems can mitigate rapid changes in net load due to variable renewable generation. Develop optimized charge/discharge schedules coordinated with renewable forecasts to smooth net load profiles.
Example:  Use predictive algorithms to schedule battery charging during periods of excess generation and discharging during peak demand to reduce ramping needs.
3.	Optimize energy and ancillary service market designs to enable storage, demand response, and distributed energy resources (DERs) to better participate. Develop market mechanisms that compensate flexibility services provided by these resources, encouraging their deployment and utilization.
Example:  Introduce time-of-use tariffs and dynamic pricing to incentivize consumers to adjust their consumption patterns, leveraging demand response as a flexibility resource.
By proactively assessing flexibility needs, harnessing the capabilities of battery storage and other IBRs, and reforming operational practices and market structures, India can efficiently integrate high IBR shares. This will require close coordination between system operators, power markets, aggregators, and flexibility providers. Robust price signals and enabling regulatory frameworks are essential to drive investment in flexibility and reward performance \cite{enel_flexibility_2023}. With the right mix of flexible resources and mechanisms, India can reliably balance supply and demand in an IBR-dominant grid.
4.2	Stability
Grid stability relates to its ability to maintain steady voltage and frequency within acceptable ranges and return to a steady-state condition within these ranges after a disturbance without cascading failures \cite{kundur_definition_1994}. With rising shares of IBRs, maintaining stability becomes more challenging due to reduced system inertia, potential oscillatory behavior, and unexpected tripping during disturbances \cite{flynn_stability_2017, nerc_ibr_2020}.
The roadmap activities outlined in this section are intended to achieve several outcomes:
•	Facilitating the development and deployment of detailed models and tools that assess IBR impacts on system stability, characterize emerging risks, and identify mitigation measures.
•	Strengthening IBR frequency response characteristics and ensuring IBRs provide adequate voltage control and reactive power support \cite{eriksson_synthetic_2017}.
•	Mitigating sub-synchronous oscillations and control interactions between IBRs and other grid management systems \cite{wang_ssci_2016}.
•	Enhancing ride-through performance to avoid tripping or cessation of active power during disturbances \cite{nerc_ibr_2018}
Activities
The following activities use these approaches to maintain and improve grid stability as IBR deployment accelerates.
4.	Develop and validate high-fidelity, vendor-specific IBR dynamic models. Collaborate with manufacturers to obtain detailed models of IBRs that accurately represent their dynamic behavior under various grid conditions. Use these models for small-signal and transient stability studies.
Example:  Use these models to simulate how a fleet of IBRs responds to voltage dips or frequency deviations, identifying potential stability issues.
5.	Conduct comprehensive system stability assessments across a range of scenarios. Perform studies that include different IBR penetration levels, fault conditions, and control system interactions to identify stability limits and critical IBR performance requirements.
Example:  Analyze the impact of a large-scale disturbance with high IBR penetration to determine the system's ability to maintain synchronism.
6.	Establish forward-looking frequency response requirements. Develop new grid codes or update existing ones to require IBRs to provide fast frequency response and synthetic inertia, enhancing the system's ability to withstand frequency excursions.
Example:  Implement mandatory requirements for new IBR installations to have grid-forming capabilities or provide inertia emulation functions.
7.	Deploy pilot projects that demonstrate advanced IBR capabilities. Implement demonstration projects with grid-forming inverters, advanced control schemes, and other innovative technologies to evaluate performance and refine technical specifications.
Example:  Set up a pilot microgrid using grid-forming inverters to test their ability to maintain stability in islanded mode.
8.	Update interconnection requirements, grid codes, and standards. Incorporate specifications from international standards like IEEE 2800 to ensure that IBRs meet the necessary performance criteria for stability, including fault ride-through capabilities and dynamic voltage support.
Example:  Amend national grid codes to mandate that IBRs remain connected and support the grid during disturbances instead of disconnecting.
9.	Enhance real-time situational awareness and decision support tools. Implement advanced monitoring systems like Phasor Measurement Units (PMUs) and develop operator tools to detect and mitigate emerging stability risks in real-time.
Example:  Use wide-area monitoring systems to identify oscillations or instabilities early and enable operators to take preventive actions.
By implementing these stability measures, India can operate the grid reliably even with very high shares of IBRs. Close collaboration between grid operators, planners, IBR developers, and manufacturers to analyze, demonstrate, and deploy advanced capabilities will be critical to maintaining a stable grid through the clean energy transition.
4.3	Resilience
Resilience refers to the grid's ability to withstand and recover from major disruptions such as extreme weather events, cyberattacks, or equipment failures \cite{NREL_resilience_2021}. While closely related to reliability, resilience focuses on mitigating the consequences of low-probability, high-impact events. The growing frequency and severity of extreme weather events poses a significant threat to India's power grid resilience, with several major blackouts triggered by such events in recent years \cite{Cyclone_Amphan_2020}.
The roadmap activities outlined in this section are intended to achieve several outcomes:
•	Enable the creation of comprehensive contingency plans considering IBR characteristics, fuel dependencies, and cyber-vulnerabilities.  
•	Establish pathways for IBRs to provide black start and restoration services that can quickly re-energize the grid post-disturbance.
•	Improve wide-area monitoring, protection, and control schemes to successfully contain cascading outages while maintaining bulk power transfer paths.
•	Facilitate the development and deployment of grid-enhancing technologies that improve IBR integration and grid resilience.
Activities
The following activities aim to leverage the growing proliferation of IBRs to build a more resilient power system:
1.	Conduct wide-area resilience studies to identify critical infrastructure. Analyze the grid to pinpoint vulnerable nodes and interdependencies. Use this information to prioritize investments and develop strategies that enhance the grid's ability to withstand and recover from disruptions.
Example:  Map out areas prone to natural disasters and assess the potential impact on grid operations, then reinforce critical transmission corridors.
2.	Design market mechanisms that incentivize resilience investments. Create regulatory frameworks that reward investments in technologies and practices that improve grid resilience, such as hardening infrastructure or deploying resilient IBR configurations.
Example:  Introduce performance-based incentives for utilities that meet specific resilience metrics or invest in grid-hardening measures.
3.	Develop technical standards and interconnection requirements for resilience. Mandate that new IBRs possess capabilities that enhance resilience, such as black start capability, ride-through during disturbances, and grid-forming functionalities.
Example:  Require that large-scale solar PV plants have the ability to support grid restoration efforts following a blackout.
4.	Implement Distributed Energy Resource Management Systems (DERMS). Utilize advanced control systems to coordinate DERs during grid disturbances, enabling them to support system restoration and operate autonomously if necessary.
Example:  Deploy DERMS to manage a fleet of rooftop solar and battery systems to provide localized power during outages.
5.	Establish cybersecurity standards for IBRs. Develop comprehensive cybersecurity protocols to protect IBRs from cyber threats, ensuring secure communication and control during both normal and abnormal grid conditions.
Example:  Implement secure authentication and encryption for remote monitoring and control of IBRs.
6.	Conduct regular resilience drills and simulations. Train operators and test systems by simulating various disruption scenarios, helping to identify weaknesses and improve response strategies in an IBR-dominant grid.
Example:  Organize emergency response exercises that simulate a major grid disturbance with high IBR penetration, involving all relevant stakeholders.
By proactively implementing these resilience strategies and solutions, India can leverage the growing shares of IBRs to build a power system that is more robust against the rising threats of hazards such as extreme weather and cyberattacks. Close coordination between policymakers, regulators, grid operators, IBR developers, and research institutions will be key to prioritizing and staging the required investments and regulatory reforms. Integrating resilience considerations into every stage of the clean energy transition is critical to delivering reliable, sustainable, and affordable power while safeguarding public safety and economic security.
4.4	System Adequacy and Planning
System adequacy means the electric system can meet the current and projected demands reliably. It is achieved through investments in assets that ensure reliable grid operation over multiple years under a wide range of uncertain future conditions. IBRs, particularly generators such as PV, introduce complexities in maintaining system adequacy due to their variable nature. To contribute to resource adequacy, IBRs must have a degree of both capacity and energy availability and assurance that can contribute to broader system-wide needs. The system as a whole needs sufficient capacity and energy availability to respond to contingency events and the protection systems in place to adequately detect and isolate faults. 
The roadmap activities outlined in this section are intended to achieve several outcomes:
•	Improve long-term grid planning tools to better characterize power system resource adequacy and the contributions of IBRs and other variable generation technologies. 
•	Modernize resource adequacy constructs to address emerging attribute risks through improved IBR modeling, accreditation, and qualification requirements.
•	Provide greater visibility into future regional system adequacy needs and capabilities through improved forecasting, planning, and reporting.
Activities
The following activities aim to improve upon existing tools and approaches to facilitate effective planning for resource adequacy under expected growth in IBR deployment.
1.	Upgrade capacity expansion and long-term planning tools to consider investments that facilitate IBR integration. This includes incorporating technologies like synchronous condensers, STATCOMs, and advanced grid-forming inverters into planning models. By doing so, planners can evaluate investments that provide necessary inertia and support grid strength, ensuring grid reliability with high IBR penetration.
Example:  Modify existing planning software to include detailed models of synchronous condensers and advanced inverters, enabling simulation of their impact on grid stability and reliability.
2.	Improve resource adequacy characterization to better assess the capacity credit of IBRs and the contingency events that should be examined. Develop methodologies for accurate estimation of capacity credits for variable renewable energy sources and storage, considering their availability during peak demand and contingency scenarios.
Example:  Implement probabilistic modeling techniques that account for the variability and uncertainty of IBR generation and develop metrics like Effective Load Carrying Capability (ELCC) for better resource adequacy assessment.
3.	Develop routines for robust grid strength assessment at multiple scales and resolutions. Utilize advanced software tools for electromagnetic transient (EMT) and phasor-domain simulations to understand the implications of planned system changes on grid strength. Create a standardized library of validated IBR models for use in these assessments.
Example:  Conduct EMT studies using detailed manufacturer-provided models of IBRs to evaluate the impact of new installations on local and system-wide grid strength.
4.	Use validated grid and IBR models to characterize grid strength and resource adequacy across a broad range of conditions. Perform extensive studies that consider various scenarios, including high renewable penetration, different load levels, and outage contingencies, to understand the limits and requirements for maintaining system adequacy.
Example:  Simulate worst-case scenarios where multiple IBRs are disconnected simultaneously due to a fault, assessing the system's ability to withstand such events.
5.	Assess IBR interactions with the grid at both current and forecasted states. Analyze how IBRs interact with the existing grid infrastructure and with each other, identifying potential issues like harmonic resonance, control interactions, and protection misoperations.
Example:  Study the potential for sub-synchronous control interactions (SSCI) between IBRs and series-compensated transmission lines.
6.	Evaluate fault detection, isolation, and protection coordination of relays at varying grid strengths and IBR proximities. Ensure that protection schemes are effective under different grid conditions, considering the lower short-circuit contributions from IBRs.
Example:  Redesign protection settings and schemes to work reliably with reduced fault currents in areas with high IBR penetration.
7.	Characterize fault responses for protection evaluation and IBR coordination. Develop a comprehensive understanding of how IBRs respond during faults to improve coordination between IBR controls and grid protection systems.
Example:  Create detailed fault ride-through profiles for different types of IBRs to inform protection strategy development.