China's electricity consumption, a key barometer of economic activity, continued stable expansion in September, official data showed on Monday.

Power usage climbed 9.9 percent from a year ago to 781.1 billion kilowatt-hours last month, according to the National Energy Administration.

Power consumption by primary industries increased by 8.6 percent year-on-year, while power consumption by secondary and tertiary sectors gained 8.7 percent and 16.9 percent, respectively.

Residential power usage saw a year-on-year increase of 6.6 percent to 103.5 billion kilowatt-hours in September, the administration said.

In the first three quarters, the country's electricity consumption rose 5.6 percent from a year earlier to 6.86 trillion kilowatt-hours.

（Picture: Veer）