Spanish electricity company Iberdrola SA (IBE.MC) said Thursday its electricity production fell 1.4% in the first half of the year to 69.85 terawatts an hour.
In a press release, Iberdrola added electricity from renewable energy sources increased 24% in the first half, making up 15% of the company's total energy production.
Iberdrola's installed capacity rose to 43.925 gigawatts in the period, 6% more than the same period last year.
Iberdrola, based in Bilbao, northern Spain, is the world's biggest wind-power generator.