SUPERIOR, Wis. — The Twin Ports of Duluth-Superior recorded its lowest level of coal cargo in three decades during the 2019 shipping season, but says it handled a record amount of freight carrying components used for generating wind power.

The decline comes as demand for renewable energy sent a record 306,000 freight tons of wind turbines and other components through the port, Wisconsin Public Radio reported.

The transition is something people would not have thought possible until recently, according to Greg Nemet, a public affairs professor at the University of Wisconsin-Madison who researches energy and policy.

"It's really a competition between coal, natural gas, and renewables. It's cheaper to make electricity with natural gas and with solar," Nemet said. "Coal really can't compete with either of those."

Last year, around 8 million tons of coal moved through the Twin Ports, the lowest volume since 1985.

As coal production in the United States has decreased from 1.2 billion tons in 2008 to a projected 597 million tons for the coming year, power companies have transitioned away from fossil fuels to appease investors and states that have set renewable energy goals.

Last week, the U.S. Department of Energy announced $125.5 million in new funding for solar technologies.

The U.S. Energy Information Administration projects coal will produce less than a quarter of the world's electricity by 2050, while renewable energy sources are expected to grow more than 20% during the same time span.