India’s electricity supply improves in cooler pre-monsoon

India’s electricity transmission network supplied a near-record amount of power in April but the system was much more stable than the year before thanks to lower temperatures and the return of some gas-fired generation.

Total electricity supplied was almost 131 billion kilowatt-hours (kWh), the fourth-highest monthly amount on record, based on data from the Grid Controller of India’s National Load Despatch Centre.

But the total was down by more than 2.3 billion kWh (-1.8 per cent ) compared with the same month a year earlier when much of the country was sweltering in an early heatwave (“Monthly operation report”, Grid India, May 24).

On the densely populated northern plain, temperatures in New Delhi’s Palam suburb averaged 28.2 degrees Celsius (82.8 degrees Fahrenheit) compared with 33.0 Celsius in the same month a year ago, cutting peak electrical loads for refrigeration and air-conditioning.

At the same time, extra generation was provided by solar farms (+1.8 billion kWh, or +23 per cent ) and coal-fired generators (+0.3 billion kWh, or +0.2 per cent ).

These increases helped offset some of the reduced output from hydroelectric generators (-3.0 billion kWh, or -25 per cent ) and gas-fired units (-0.3 billion kWh, or -10 per cent ).

The combination of lower temperatures and increased solar generation significantly reduced stress on the transmission system, especially during the afternoon peak.

System frequency fell below the minimum acceptable threshold of 49.9 cycles per second (Hertz) only 11 per cent of the time in April 2023 compared with a record 32 per cent in April 2022.

Although gas-fired generation was down slightly compared with the previous year, it rose by more than 0.5 billion kWh compared with March, to the highest level for 12 months, as the cost of imported liquefied natural gas fell.

But despite lower average temperatures, peak demand increased by 4.2 per cent compared with the year before, reflecting underlying load growth from the growing number of appliances connected to the system.

Rapid underlying load growth will continue to make the system vulnerable in future heatwaves.

Coal security

Coal-fired power generators held stocks equivalent to 12.8 days of consumption at the end of April, up from just 8.0 days at the end of the same month in 2022, reducing the risk of generator outages as a result of fuel shortages.

Domestic coal production increased by 35 million tonnes (+10 per cent ) in the first four months of 2023 versus the same period in 2022 as the government pressed for more output to avert a repeat of the previous year’s blackouts.

The volume despatched to power producers via the railroads was up by a more modest 12 million tonnes (+5 per cent ) reflecting congestion on the network.

Combined with lower temperatures and lower generation, the increase in coal deliveries was sufficient to rebuild generator inventories to a more comfortable level and avoid previous fuel problems.

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