U.S. coal-fired power generation is set to rebound in the winter months as surging natural gas prices prompt utilities to switch from gas to using more coal. U.S. benchmark natural gas prices at Henry Hub have jumped from $4.23 per million British thermal units (MMBtu) at the start of November to nearly $5 per MMBtu by early December. Early on Wednesday, prices were up by +2.07% at $4.941 per MMBtu. That’s the highest price in three years, as a polar vortex with freezing temperatures and snowstorms gripped the U.S. Midwest…