MARION, Ill. (AP) — The Southern Illinois Power Cooperative plans to shutter its largest coal-fired generator this fall, which is expected to save it $125 million over a decade but cost up to 26 workers their jobs.

The Southern Illinoisan reports that President and CEO Don Gulley said the tentative decision to close Unit 4, as it is known, was based on more competitive energy prices on the open market and a need to diversify SIPC’s energy sources.

He says retiring Unit 4 will reduce total carbon emissions at the Marion plant by 50%. The tentatively approved plan awaits final regulatory approvals which are expected by late July.