Energy

The two nations topping the world in greenhouse gas emissions agreed at the Paris talks to cut way back. But critics have stalled a key part of the U.S. plan, and China's good start may be fragile.

Tesla is building what it says is the world's largest battery factory. The scale is expected to drive down the cost of electric cars and batteries that homeowners can use to store surplus solar power.

Peabody Energy, the largest coal company in the United States, filed for bankruptcy on Wednesday. The company is the second major coal company based in St. Louis to file for Chapter 11 protection.

As the coal industry struggles with falling prices, weak Chinese demand, regulatory changes and competition from fracking, St. Louis-based Peabody has filed for Chapter 11 bankruptcy protection.

Nuclear power is carbon-free and remains the source of about 20 percent of U.S. electricity. But natural gas, wind and solar are often cheaper, and unprofitable reactors are being shut down.