US utility Northern Indiana Public Service Company (NIPSCO) has locked out 1,600 union workers, a move that could affect coal plant operations.
NIPSCO locked out the workers on 2 April, after its labor contract with the United Steelworkers expired. The company and union began contract negotiations on 20 January but have yet to reach a new collective bargaining agreement, NIPSCO said on Wednesday.
The lockout "will remain in place until the union agrees to the company's last, best and final offer and a new agreement is reached," NIPSCO said.
The union says NIPSCO stopped negotiating after submitting its last offer. In addition, "we are not going to accept their last, best, and final offer because it was not in the best interest of our members," said Jon Doust, USW District 7 sub-district director.
The affected workers hold a variety of jobs at NIPSCO, including linemen and clerical positions. Some members have positions at the utility's RM Schahfer coal- and natural gas-fired power plant.
But the impact of the lockout on power plant operations could be delayed. Electricity demand in general is typically subdued during the so-called spring shoulder season months. This is particularly true for fossil fuel generation. April and May are months when US coal units are typically scheduled for maintenance outages.
In addition to Schahfer, NIPSCO operates the Michigan City coal plant in Indiana, which the company is planning to close in 2028, as well as the Sugar Creek natural gas plant and some wind and solar generating facilities in the state.
Maintenance at NIPSCO's coal power plants is ongoing but may be slowed by the lockout, Doust said, "or they are hiring even more contractors than they normally would to backfill the fact that we're locked out and not doing our part." The two coal units at the Schahfer plant are not producing any power at the moment, he said.
NIPSCO said it has implemented continuity plans to maintain operations during the lockout. According to the utility, trained non-represented employees and contractors, with support from affiliated companies, are performing work in line with existing safety procedures.
The utility is continuing to comply with a US Department of Energy (DOE) emergency order to keep Schahfer's coal units - 17 and 18 - available for generation dispatch if needed, NIPSCO said. Before the order the two units, which have a combined capacity of 848MW, had been slated to retire by the end of last year.
Schahfer sells power into the Midcontinent Independent System Operator. Neither the grid operator nor DOE immediately responded to requests for comment.
The Schahfer plant took 588,606 short tons (533,975 metric tonnes) of coal in all of 2025 and 95,216st in January 2026 from Peabody Energy's Gateway mine in Illinois, US Energy Information Administration data show. In January, the Schahfer plant burned 90,574st of coal.
