China's power generation increased 11.5 percent from a year earlier to 386.1 billion kilowatt-hours in September, the National Bureau of Statistics said on Tuesday.

It is the eighth consecutive month that electricity output has expanded at a double-digit pace after sinking into single digits late last year when Beijing launched a campaign to cap energy use.

On a daily basis, September output, at 12.87 billion kWh, was lower than the previous three months when summer heat drove monthly generation above 13 billion kWh.

The Statistics Bureau did not indicate generation by source in the release.

National hydropower output in September fell 24.5 percent from a year earlier to 56.87 billion kWh, while water stocks used by key hydro stations declined 18.5 percent to 104.9 billion cubic metres at the end of last month, the National Development and Reform Commission said.