Energy

As treaties end, Russia focuses on hypersonic weapons that could “tighten the noose” on current U.S. defenses

Declining solar costs have helped spur a move away from coal

New Mexico and Nevada are poised to enact far-reaching changes to reduce greenhouse gas emissions

The microscopic particles unleashed by the plant’s explosions are also a potential environmental and health concern

The shift underscores declining storage costs, but questions remain on whether the move will bring down emissions

The U.S. has been slow to embrace the technology, even though Japan and China are zooming ahead

A number of studies about number two

Researchers built a small, flexible device that harvests wi-fi, bluetooth and cellular signals, and turns them into DC electricity. Christopher Intagliata reports.

Several companies are diversifying their businesses, from biofuels to electric vehicles

An international fusion project could help the nation eventually develop its own, smaller reactor

Energy economists say the new home requirement is inefficient and benefits wealthier people; supporters say it’s just one piece of the puzzle

One power company announces a goal of 100 percent clean energy as a near-record number of coal-fired power plant close