The operator of New England’s power grid says rolling blackouts are a possibility amid skyrocketing natural gas prices and supply shortages.

According to the Bangor Daily News, ISO New England President and CEO Gordon van Welie says rolling blackouts that affect different people for short periods of time are an option to preserve energy as a last resort. He warned that an overreliance on natural gas could put the grid in jeopardy if there’s an extended cold snap this winter.

The grid relies on liquefied natural gas and heating oil when there isn’t enough natural gas, but there are supply shortages of both this winter.

Acting Maine Public Advocate Andrew Landry says he’s confident ISO New England is evaluating other options to avoid controlled outages.

It comes as Mainers brace for rising electricity costs this winter.