Iraq’s oil exports from the southern ports fell slightly in June as power generators burning more fuel to keep up with demand for air conditioning increased domestic demand, an official at the state-run South Oil Company said on Friday.

Loadings from Iraq’s southern oil terminals, on the Gulf, ran at an average daily rate of 3.175 million barrels, compared with 3.2 million barrels per day (bpd) in May, he said.

Crude supply to local oil refineries rose due to the increase in demand for electricity for cooling during summer in OPEC’s second-largest producer, he said.

The southern region produces most of the OPEC nation’s crude oil. The northern Kurdish regional government exports about 500,000 bpd through a pipeline to the Turkish port of Ceyhan, on the Mediterranean, but independently from the central government in Baghdad which oversees crude sales from the south.

Iraq, which relies on oil for nearly all its revenue, made$3.845 billion in revenue from oil exports in June, selling at an average price of $40.37 a barrel, an oil ministry spokesman said. June’s revenue was higher than April as prices increased.

Iraqi officials and oil analysts expect further growth in the country’s exports this year, but at a slower rate than 2015 when it was the fastest source of supply growth in OPEC.