In a recent ruling, the Central Electricity Regulatory Commission (CERC) instructed the states of Maharashtra, Gujarat, Chhattisgarh, and Madhya Pradesh to strictly adhere to the action plan aimed at enhancing the reliability and security of the electricity grid in Western India. The states must submit quarterly progress reports to the Western Regional Load Despatch Center (WRLDC) detailing the plan’s implementation.

However, the Commission refrained from imposing any penalties on the respondents — electricity distribution companies (DISCOMs) and transmission companies of the four states.

The CERC urged these states to expedite the implementation of the Automatic Demand Management System (ADMS) and enhance their demand forecasting and estimation systems to minimize deviations from the allocated schedules for electricity consumption.

It directed the states to ensure that the demand ramp does not exceed 100 MW, as per the Grid Code. The Commission emphasized the importance of regular reviews of coal stock levels in thermal power plants to guarantee a stable fuel supply for power generation.

The CERC has made it clear that if the grid frequency falls below acceptable levels, all State Load Despatch Centers (SLDCs) must be prepared to swiftly implement emergency measures to control overdrawals during low-frequency situations to safeguard the integrity of the grid.

WRLDC had filed a petition seeking appropriate orders from the Commission regarding the over-drawal from the grid by regional entities leading to insecure operation of the grid.

Background

WRLDC is responsible for the integrated operation of the electricity grid in the western region, which comprises the power systems of Maharashtra, Gujarat, Madhya Pradesh, Chhattisgarh, Goa, and union territories of Daman & Diu and Dadra Nagar Haveli.

The issues brought up in the petition stemmed from the operational difficulties encountered by the Western Region’s electricity grid between August and October 2021. Within this timeframe, the grid faced a notable decrease in frequency, dropping below the necessary levels for safe and reliable operation. This extended decline in frequency gave rise to significant apprehensions regarding the grid’s overall security and stability.

Numerous factors contributed to these challenges, which included instances of thermal generation outages, diminished hydro generation, fluctuating wind speeds, and reduced internal power generation. This situation underscored the critical importance of effective state-level planning to adequately meet the increasing post-monsoon electricity demand and comply with grid regulations and reliability standards.

Despite warnings issued by WRLDC, the overdrawal persisted. Emergency measures, such as opening radial feeders, had to be implemented to contain overdrawal and restore grid frequency to safe operating limits during this period.

A similar pattern of overdrawal and low-frequency operation continued even after October 2021. Even at a frequency below 49.90 Hz, Gujarat has over-drawn in the range of 600-1100 MW, Maharashtra by 800-1000 MW, Madhya Pradesh by 700-1100 MW, and Chhattisgarh in the range of 200-300 MW.

CERC initiated proceedings on this matter and held an initial hearing on April 21, 2022. During the hearing, CERC requested the petitioner to provide specific instances of constituents not complying with grid discipline directions. Subsequently, WRLDC submitted a supplementary affidavit on May 4, 2022, containing detailed examples of violations, providing more specific quarterly progress reports to WRLDC regarding its implementation.

The WRLDC held meetings with the SLDCs and proposed an action plan to be implemented by the SLDCs. The plan included drafting quarterly resource adequacy statements, timely implementation of demand management measures, improved renewable energy forecasting, review of ADMS, addressing supply-side issues like coal shortage, and implementing ADMS programs across all DISCOMs. It also involved the identification of radial feeders for manual tripping as emergency measures and implementing spinning reserves within the state.

The primary issue raised by the petitioner revolved around state entities drawing excessive power, which subsequently resulted in frequency-related problems.

During the mentioned period, WRLDC issued numerous violation messages and took emergency measures to contain overdrawal.

Maharashtra

Maharashtra consistently exceeded its power draw by 200-900 MW in multiple time intervals, even when the grid frequency dropped below 49.90 Hz. During August to mid-October 2021, Maharashtra had overdrawn power in the 1-7 MU range. Approximately 0.5% to 1% of its daily energy needs were met through overdrawing power from the grid, while around 4-8% of its daily energy consumption was satisfied by purchasing power from various segments of the short-term electricity market. The highest short-term purchase occurred during September 20-28, 2021, reaching up to 12-14% of daily consumption, with 2-4% sourced from the real-time market.

In its submission, the Maharashtra SLDC said it faced challenges with several thermal power units going offline in Maharashtra for various reasons. Among these, fifteen units with a combined capacity of 5,190 MW experienced disruptions due to a coal shortage. To address the overdrawal of power by Maharashtra, the Maharashtra SLDC swiftly increased hydroelectric generation.

Additionally, the Maharashtra SLDC stated that it had already implemented various measures, including automatic under-frequency load shedding, which involved reducing the frequency from 49.4 Hz to 48.80 Hz in four incremental steps, following the WRPC’s plan. The center also mentioned that it had introduced corrective actions such as enhancing renewable energy forecasting and addressing agricultural demand feeders. However, some of these initiatives encountered delays primarily due to administrative issues.

During this specific timeframe, the Maharashtra State Electricity Distribution Company (MSEDCL)  optimized its contracted hydroelectric resources despite facing annual constraints on water usage. MSEDCL procured 679.36 MUs from the market at a rate of ₹20 (~$0.0241)/kWh and had the capacity to purchase a maximum of 3600 MW. Furthermore, MSEDCL explored power exchange options with other states, scheduling a transfer of 200 MW from October 16, 2021, to November 30, 2021, and from February 16, 2022, to March 31, 2022, in partnership with Tata Power Delhi Distribution Company.

Measures were taken to address the high electricity demands during the morning and evening peak periods, including reducing three-phase power availability to agricultural consumers by two hours limiting it to eight hours during both time slots. Additionally, staggered time schedules were introduced for various agricultural groups to mitigate sudden surges or drops in demand caused by changes in agricultural loads.

To cope with these challenges, MSEDCL explored the possibility of power banking with other states and finalized a schedule to transfer 200 MW of power from October 16, 2021, to November 30, 2021, and from February 16, 2022, to March 31, 2022.

MSEDCL primarily relied on long-term PPAs to fulfill peak demand requirements. During the peak summer months of April and May 2022, it operated its hydroelectric generation facilities at maximum capacity. Despite the use of advanced forecasting by renewable energy generators for solar and wind energy, there were instances of inaccuracies in actual power generation.

Madhya Pradesh

The overdrawal of power by Madhya Pradesh consistently exceeded 400-1,200 MW, even when the grid frequency dropped below 49.90 Hz. Madhya Pradesh had overdrawn power in the 2-9 MUs range during the said period. Madhya Pradesh fulfilled 0.5% to 4% of its daily energy needs through these overdrawals from the grid. The state sold energy equivalent to 3% to 16% of its daily energy consumption, translating to 5-30 MUs in the short-term market.

Notably, short-term sales reached 20-30 MUs between September 19 and October 3, 2021, a period when Madhya Pradesh was significantly over-drawing power, coinciding with the grid operating at very low frequencies ranging from 49.5 Hz to 49.7 Hz.

The Madhya Pradesh Power Management Company (MPPMCL) and the Madhya Pradesh Power Transmission Company (MPPTCL) emphasized their unwavering commitment to maintaining grid discipline and ensuring the secure operation of the integrated grid. They underscored that no grid disruptions could be attributed to Madhya Pradesh during the period in question.

They provided an overview of the factors contributing to inadvertent overdrawal in the state, including increased agricultural pump load during dry spells, the unpredictable nature of wind generation, reduced generation from hydro projects due to low reservoir levels, coal shortages impacting power plants, and the absence of alternative options.

Madhya Pradesh experienced a slight increase in deviations during the final week of August 2021, primarily due to several units from independent power producers.

Furthermore, they pointed out that Madhya Pradesh possesses adequate hydroelectric generation capacity to meet peak and contingency demands without resorting to grid overdrawal. However, the state had to procure power from the open market due to limited alternatives.

Additionally, they highlighted ongoing developments, including implementing the energy portfolio management system by Power Finance Corporation Consultancy and the automatic demand management program and load trimming programs within the state’s transmission network, all aimed at ensuring the grid’s reliability.

Gujarat

The overdrawal by Gujarat remained in the 400–1200 MW range in several time blocks, even at a frequency below 49.90 Hz during the period from August to mid-October 2021. Gujarat had met 0.5 % to 2.5% of its daily energy consumption by overdrawing from the grid by 2-7 MUs. Gujarat had met around 20-35% of its daily energy consumption by purchasing from various segments of the short-term electricity market.

The Gujarat SLDC highlighted that since August 2021, the state has been grappling with an unprecedented power situation. This situation was characterized by various factors, including unit outages at APL (Mundra), concerns related to coal quality and shortages at state-owned power plants, significant increases in variable costs for gas plants, and the challenges posed by the intermittent nature of wind and solar power generation.

During the specified period, the Gujarat SLDC pointed out that there were more instances of underdrawing blocks than overdrawing blocks, which indicated that there was no deliberate intent to exceed the grid draw limits to meet power requirements. State utilities heavily relied on the market, obtaining 30% to 40% of their energy from the short-term open access market.

To curtail overdrawal, measures were put in place, including restrictions on agricultural feeders, and a reduction in agricultural demand occurred naturally due to widespread rainfall in September 2021. Additionally, the Gujarat SLDC enforced load relief by imposing restrictions on the Jyoti Gram Yojana, a government program that provides 24×7 three-phase power supply to rural areas, starting October 1, 2021.

The Gujarat SLDC further explained that it took proactive measures to limit unscheduled overdrawal and ensure that drawal remained within established limits. These actions included promoting internal generation within DISCOMs, collaborating with the Gujarat Urja Vikas Nigam (GUVNL) to reduce agricultural supply hours, introducing staggered scheduling for industrial activities, and improving demand and renewable energy forecasting.

Additionally, it encouraged state-generating companies to expedite the revival of thermal units, optimized internal power generation and imposed load restrictions to control overdrawal. Initiatives were also launched to explore automatic load trimming programs, develop various methods for estimating demand, and activate the automatic demand management program in state-owned DISCOMs.

The Gujarat SLDC prepared reports on demand and resource availability, evaluated special protection programs, and implemented measures such as load trimming and under-voltage load shedding to enhance grid security.

Chhattisgarh

Chhattisgarh consistently exceeded its power draw by 200-450 MW during various periods. Over this time frame, Chhattisgarh’s power overdraws ranged from 0.5-3.5 MUs. Chhattisgarh managed to meet 1% to 3% of its daily energy needs by over-drawing power from the grid. From September 19, 2021, and lasting until October 5, 2021, Chhattisgarh sold between 3% and 15% of its daily energy consumption, equivalent to 2.5-12 MUs, in the short-term market.

Notably, from September 19, 2021, to September 26, 2021, when Chhattisgarh significantly exceeded its power draw, the state’s short-term sales reached 8-12 MUs.

In its response, the Chhattisgarh SLDC explained that it actively addressed the low Available Transfer Capability (ATC) issue by implementing various programs to increase the ATC limit. The instances of simultaneous overdrawing and sales in the short-term market were attributed to unforeseen fluctuations in system demand and pre-committed sales that were not deliberate actions.

During the specified period, it calculated a maximum thermal generation outage of 39.78%, equivalent to 1130 MW out of a total capacity of 2840 MW, with the highest daily outage recorded at 27.12 MUs. The Chhattisgarh SLDC also faced forced outages of thermal units in August (9 instances), September (10 instances), and October (10 instances) of 2021. To manage the issue of overdrawal, it relied on unscheduled load shedding, which was implemented 111 times in August 2021, 16 times in September 2021, and 39 times in October 2021. Despite these challenges, the Chhattisgarh SLDC asserted that it diligently fulfilled its responsibilities without intentional violations.

Chhattisgarh SLDC stated in its reply that it actively addressed low ATC issues by implementing various programs to increase the ATC limit. The reported simultaneous overdrawing and sales in the short-term market were attributed to unexpected system demand fluctuations and pre-committed sales that were not deliberate actions. It calculated a maximum thermal generation outage of 39.78% (1130 MW out of 2840 MW capacity) during the specified period, with the highest daily outage at 27.12 MUs.

It experienced forced thermal unit outages in August (9 instances), September (10 instances), and October (10 instances) 2021. To manage overdrawal, it relied on unscheduled load shedding, which was employed 111 times in August 2021, 16 times in September 2021, and 39 times in October 2021. Despite the challenges, Chhattisgarh SLDC asserted that it diligently performed its duties without deliberate violations.

Commission’s Analysis

The Commission observed that, due to excessive power drawal by certain state entities, the grid frequency dipped below the prescribed lower limit of 49.90 Hz on numerous occasions between mid-August and mid-October 2021. During this period, the frequency remained below 49.90 Hz for a total of 117 hours, and at times, it reached exceptionally low values ranging from 49.5 to 49.7 Hz. Furthermore, the frequency remained below 49.7 Hz for a combined duration of 4.2 hours.

It noted that the overdrawal by the states takes the grid to a stressed situation that must be avoided. It is also necessary that reserves are maintained by the states on a day-to-day basis so that overdrawal is minimized in such situations and complies with the directions of RLDC, as the grid cannot be left in a vulnerable condition.

The state regulator directed the respondents to strictly adhere to the specified action plan and mandated that SLDCs provide quarterly progress reports to WRLDC regarding its implementation. Any necessary action plan modifications should be discussed and finalized in the Regional Power Committee.

CERC added that the types of messages issued by WRLDC have been reviewed and recommended that the logic for sending these messages be defined precisely in the operating procedure to ensure clarity for the states.

CERC, in this case, desisted from imposing any penalties on the respondents and encouraged the petitioner to approach the Commission if it encounters issues with action plan implementation or non-compliance with the issued directives.

Recently, CERC, in response to a petition filed by the Southern Regional Load Despatch Centre regarding critical operational challenges of the grid in South India, directed the states to provide quarterly progress reports to SRLDC on actions taken to ensure grid stability.

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