Lower production in Spain and the US resulted in Iberdrola earnings from renewables slipping to €1.165bn in the first half of the year, compared with €1.184bn in the same period of 2018.
The company said higher offshore wind production, particularly the Wikinger project, and power prices helped compensate for the fall in output in Spain and the US.
In Spain, overall clean power production was down 27.6%, with hydro falling over 45% and wind by 8.3%.
Output was also down in the US and the UK, however, earnings in the latter market were up on 2018 as a result of higher power prices, Iberdrola said.
The company added 1188MW of new renewables capacity in the first half of the year, and expects to have installed a total of 5250MW in the 12 months by the end of 2019.
The new capacity will comprise 476MW of offshore wind in the UK, 1333MW of onshore wind mainly in the US, Mexico and Spain, 272MW of solar and 611MW of hydro.
Overall, the Spanish energy company posted a net profit of over €1.644bn in the first six months of 2019, up from more than €1.41bn last year.
The company said the net profit was boosted by good performances in the retail, networks and generation businesses.