LONDON  - China’s electricity consumption smashed the previous record in July as a prolonged heatwave settled over major load centres, especially in the Yangtze Delta, driving an enormous increase in air-conditioning and refrigeration.

Unprecedented load was met by record output from hydro and solar, ensuring coal-fired generation fell slightly compared with the same period a year earlier, showcasing the rapid transformation of the system.

Total generation increased to a record 883 billion kilowatt-hours (kWh) in July from 846 billion kWh in the same month in 2023 and 806 billion kWh in 2022, according to the National Bureau of Statistics.

Much of the increase was down to a long period of exceptionally hot weather in eastern regions, especially province-level areas lying on the lower reaches of the Yangtze, including Shanghai, Zhejiang, Jiangsu and Anhui.

Chartbook: China electricity generation

Daily temperatures at Nanjing in the Yangtze Delta averaged 30.4 °C compared with 28.7 °C a year earlier and about 2.5 °C above the long-term seasonal norm.

Nanjing temperatures have been above normal in 42 of 50 days since the start of July, pushing airconditioning and refrigeration demand to a record.

The delta is home to 237 million people, 17% of the country’s total population, and accounts for 24% of national economic output, making it the largest load centre.

As a result, regional heatwaves can drive peak consumption across the entire national transmission network and draw in power from provinces to the west and south.

Several cities and provinces in the delta called for conservation during the heatwave to lower electricity demand.

But overall the transmission system coped because record consumption was more than matched by huge increases in hydro and solar generation in other parts of China.

RECORD HYDRO

Nationwide hydro generation increased by 45 billion kWh compared with the same month a year earlier while output from solar farms was up by 10 billion kWh with a smaller increase from wind farms of 5 billion kWh.

The result was that thermal generation, almost all from coal, declined by 25 billion kWh compared with July 2023, despite record electricity demand.

Unprecedented amounts of hydro power were transmitted from dams on the middle and upper reaches of the Yangtze eastwards to the delta.

Hydro generation surged to a record 166 billion kWh in July from 121 billion kWh in the same month a year earlier, easily passing the previous seasonal record of 146 billion in 2022 and 2020.

After the drought lasting from the middle of 2022 to the end of 2023, plentiful monsoon rains enabled generators to make full use of newly commissioned cascade dams on the Yangtze system for the first time.

Even now, enormous volumes of water are still impounded behind dams and in seasonal reservoirs for flood control, which is likely to sustain hydro generation at record seasonal levels through August and into September.

SOLAR SURGE

Electric reliability during the summer peak was also guaranteed by unprecedented deployment of solar farms and record generation from solar power.

Solar generation surged to a record 36 billion kWh in July from 26 billion kWh in the same month in 2023 and 21 billion kWh in 2022.

Solar generation has been driven by a huge increase in installed capacity, which has more than doubled since the end of 2021.

The figures do not include increasing amounts of self-generation by residential and commercial users from rooftop solar panels.

COAL DOMINANT

Extra generation from hydro and solar reduced the system’s reliance on fossil fuels during the summer peak but it remained very high.

Thermal producers still accounted for 65% of all generation in July down from 71% in 2023 and 73% a decade ago.

Thermal generation may be declining relative to other sources of electricity but it has still grown in absolute terms over the last decade because total demand has increased so fast.

Thermal generation amounted to 454 billion kWh in July, down slightly from a record 471 billion kWh in last year’s drought, but up by a third from 340 billion kWh in 2014.

EFFICIENCY DRIVE

Most of China’s best sites for run-of-river dams have been developed, limiting further gains in hydro output, though there is increasing interest in pumped storage.

The government plans further deployment of solar and wind to boost renewable generation and there are rapidly increasing amounts of small-scale rooftop solar which will cut net load on the transmission network.

Nuclear remains a small part of the system, accounting for 5% of generation in 2023, though the government has approved a big reactor building programme which will boost it significantly by the end of the decade.

However, further reductions in coal combustion depend on major improvements in efficiency among generators and users to reduce coal-firing and slow load growth to allow renewables to play an even bigger role.

John Kemp is a Reuters market analyst. The views expressed are his own. Follow his commentary on X https://twitter.com/JKempEnergy

(Editing by Louise Heavens)