The frigid winter that froze much of the country also caused a surge in electricity demand. Natural gas prices soared to their highest level in years. So U.S. power plants trying to balance higher energy demand with rising fuel costs fired up more coal burners to keep consumer energy costs at bay.
Coal's recent growth naturally has created a ripple effect in the economy. Coal has boosted businesses throughout the supply chain including L&H Industrial, a Gillette, Wyo.-based maker of mining equipment. "Approximately 30 percent of our business is derived from coal mining," L&H Industrial's Joel Christophersen told CNBC recently. "That's a major contributor to the economy of our state."
Beyond growth prospects, energy providers like coal for its stability. Fuel naturally is the biggest cost for any power plant. And because coal supplies are less volatile than natural gas stockpiles, coal prices don't fluctuate as much. That's why coal still is the country's single biggest fuel source—accounting for nearly 40 percent of all the electricity generated in the U.S., according to government data. That's more than natural gas, solar and wind sources—combined.