Power transmission in India stabilises as supply improves
India’s electricity transmission network supplied a near-record amount of power in April but the system was a lot 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 kilowatthours (kWh), the fourth-highest monthly amount on record, based on data from the Grid Controller of India’s National Load Dispatch Centre.
But the total was down more than 2.3-billion kWh (-1.8%) compared with the same month a year earlier when much of the country was sweltering in an early heat wave.
On the densely populated northern plain, temperatures in New Delhi’s Palam suburb averaged 28.2°C compared with 33°C 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%) and coal-fired generators (+0.3billion kWh, or +0.2%).
These increases helped offset some of the reduced output from hydroelectric generators (-3-billion kWh, or -25%) and gas-fired units (-0.3-billion kWh, or -10%).
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% of the time in April 2023 compared with a record 32% in April 2022.
Though gas-fired generation was down slightly compared with the previous year, it rose by more than 0.5-billion kWh compared with March’s, to the highest level for 12 months, as the cost of imported liquefied natural gas fell.
But despite lower average temperatures, peak demand increased 4.2% 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 heat waves. Coal-fired power generators held stocks equivalent to 12.8 days of consumption at end-April, up from just eight days at the end of April 2022, reducing the risk of generator outages due to fuel shortages.
Domestic coal production increased by 35-million tonnes (+10%) in the first four months of 2023 versus 2022’s matching period as the government pressed for more output to avert a repeat of the previous year’s blackouts. Volume dispatched to power producers via the railroads was up by a more modest 12-million tonnes (+5%) 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.