(Yicai Global) June 14 – Hydroelectric power generation in China’s Sichuan and Yunnan provinces, which account for 80 percent of the country’s hydropower generation, has been badly affected by the dry and hot weather.

In April, hydropower generation in southwestern Yunnan province plunged 41.9 percent in April from the same period last year, and while that in neighboring Sichuan province plummeted 11.9 percent, according to data from the National Bureau of Statistics.

And in the first four months, Yunnan’s hydropower generation from January to April sank 11.4 percent, although that in Sichuan province increased by 6.5 percent over the period.

“During this year’s high-water season, Sichuan province was hotter than usual and there was less rainfall, challenging the overall hydropower supply,” Shen Yanbo, senior engineer at the China Meteorological Administration’s Wind and Solar Energy Center, said at an industry forum held earlier this week.

Compared with last year, the distribution of rainfall was uneven and there were periodic droughts and floods, he said. Big swings in temperature and rainfall have a great effect on hydro-electric power generation.

High temperatures will become the norm amid global warming, the distribution and timing of precipitation will become more irregular, and there could be more extreme weather patterns such as downpours and droughts, Shen said. A lot of renewable energies are highly dependent on the weather and climate and therefore the electricity sector needs to pay attention to this.

Huaneng Lancang River Hydropower in Yunnan province generated about 15.6 billion kilowatt hours of electricity during the first three months, a drop of 11.4 percent from the year before. It supplied 15.4 billion kilowatt hours to the grid, a year-over-year fall of 11.4 percent.

There was insufficient water during last year’s high-water season, which resulted in the drop in electricity production, the NBS said. Water inflows into the Lancang River were 10 percent less in the first quarter than the same period last year.

As a result, since March, Yunnan province has carried out load-shedding in some sectors and a number of electrolytic aluminum producers have been asked to reduce output.

Some 38.6 billion cubic meters of water from reservoirs have been used to replenish the upper reaches of the Yangtze River, the Changjiang Water Resources Commission of the Ministry of Water Resources said on June 10. This has raised the water levels of the middle and lower reaches by between 0.5 meters and 2.5 meters to ensure the shipping industry, natural ecology and hydropower generation in the river basin.

Editors: Shi Yi, Kim Taylor