India’s power transmission system broke previous records for generation and consumption in August, according to the latest monthly data from the Grid Controller of India.

Still, grid stability improved as increasing output from coal-fired generators offset a shortage of hydropower sources affected by an erratic monsoon.

As in China, the system’s performance highlights the inconvenient truth: Coal is still the marginal fuel that keeps the lights on despite the rapid expansion of renewable energy.

Total electricity consumption for the month rose to a record 152 billion kilowatt hours (kWh), surpassing the previous record of 140 billion kWh in June and an increase of just 130 billion kWh in the same month last year.

The system set a new concurrent load supply record of 237 gigawatts (GW), up from the previous record of 223 GW in June and just 195 GW in August 2022.

Total generation from all sources increased by 21 billion kWh (+16 percent) compared to the same month in 2022. (“Operational Performance Report,” Grid India, September 25).

The majority of additional generation came from coal-fired power plants (+16 billion kWh), with smaller contributions coming from wind farms (+3 billion kWh), solar (+2 billion kWh) and gas (+2 billion kWh).

Due to erratic monsoon rains and depleted reservoirs, hydropower generation fell slightly (-1 billion kWh), meeting only 16 percent of total demand, compared to 19 percent the year before.

IMPROVED RELIABILITY

The transmission network delivered record load while avoiding the severe instability and widespread power outages that occurred in 2021 and 2022.

The frequency of the power grid is a general indicator of the reliability of the network, with an underfrequency signaling that generation is insufficient, while an overfrequency signals that there is too much being generated to meet the load on the system.

Frequency fell significantly between August 29 and September 1 – a sign that generators were unable to fully meet record peak demand.

The average frequency was just 49.94 to 49.96 cycles per second (Hertz), compared to a target of 50.00 for the entire four-day period.

On the most affected days, the frequency fell below the minimum acceptable value of 49.90 Hertz up to 25 percent of the time.

However, throughout the month the system was more stable, with fewer, shorter and less severe periods of underfrequency.

The frequency fell below the minimum acceptable threshold only 7 percent of the time, compared to 9 percent in the same month last year.

COAL-FIRED generation

The grid increased coal-fired power generation to a near-record 104 billion kWh in August.

Improved fuel availability ensured that coal-fired power plants could operate when needed – preventing the severe blackouts and blackouts that impacted the grid in October 2021 and again in April 2022.

To ensure there is enough fuel, India’s domestic mines increased coal production by nearly 65 million tonnes (+11 percent) in the first eight months of 2023 compared to the same period in 2022.

According to the Coal Ministry, the rail network transported an additional 24 million tons (+5 percent) to power generators in the same period.

India’s railways sent an average of 248 coal trains to generators daily in August 2023, up from 233 in August 2022 and 211 in August 2021.

As a result, towards the end of September 2023, power generators still had supplies equivalent to nine days of consumption. That’s a slight decrease from the same month in 2022, but significantly more than the four days in 2021 that triggered a power crisis.

In the long term, the rapid growth of renewable energy will reduce the need for coal burning on such a large scale, but coal emissions are still several years in the future.