DATONG, China -- Scott Pruitt, the head of the U.S. Environmental Protection Agency, declared Monday that "the war on coal is over." He told an audience in Kentucky that he plans to repeal an Obama-era rule that limits carbon emissions from power plants that burn coal.

China, on the other hand, is doing the opposite. Coal is on the way out and solar power is coming in.

On a farm in northern China, they are planting a new crop: Nearly 200,000 solar panels in the heart of coal country.

In the south, China flipped the switch on the world's largest floating solar installation -- built on top of a lake created by an abandoned coal mine. Projects like these helped China double its solar capacity last year. It is now twice as big as the U.S. capacity.

Workers in China work on a new solar panel installation in Datong. CBS News

Nearly half of all the solar installations in the world are now happening in China and they're doing it quickly. Greenpeace says they are installing the equivalent of a soccer field full of solar panels, every hour of every day.

"We have 28 solar power plants in operation in china and three more are under construction," said Maggie Qiu, the executive president of Panda Green Energy. It has installed enough solar panels to power more than 40 million homes.

Qiu said they are building the solar farms because they "intend to bring a better future to our next generations by using such clean energy, reducing the air pollution -- that's the company's mission."

It's also the government's mission. It's spending hundreds of billions of dollars to subsidize renewable energy as China tries to wean itself off coal -- still its dominant power source and the reason for its notoriously toxic air.

But China now produces two-thirds of the world's solar panels and has become a major competitor for the U.S. solar industry, which employs a quarter million of American workers.