Aramco’s huge IGCC power plant, integrated with a new refinery at Jazan, is ready for commissioning. But, with Houthi rebels in nearby Yemen getting more ambitious in their infrastructure attacks, and no link to the Saudi oil pipeline network, the plans look as uneconomic as ever.

State firm Saudi Aramco’s whopping 4GW integrated gasification combined cycle (IGCC) plant, under development at Jazan in the remote southwest of Saudi Arabia, is about to enter the commissioning...