Duke Energy Corp., one of the biggest US electric utilities, has backup plans that include relying more on gas-fired power generation in case a threatened US rail strike stops the flow of coal to its plants.

“Continued rail transportation is a critical component to maintaining reliable operations however, in the event of a strike, we have contingency plans in place to mitigate a disruption,” spokeswoman Jennifer Sharpe said Wednesday in an email.

Duke has “sufficient” coal supplies to withstand a “limited disruption” and plans include ramping up natural gas and fuel oil generation at its power plants, she said. The Charlotte, North Carolina-based company could also use trucks to transport coal if a strike disrupts supply.

Duke has 11 coal-fired power plants and coal is behind around 22% of the energy the utility generates, according to the company’s website.