August 6, 2018, 12pm PDT
A proposal by the nation's largest utility could be a model to deal with the most formidable problem presented by intermittent renewable electricity sources.
November 13, 2012, 7am PST
Cynthia Barnett says Americans live under an "illusion of water abundance" and calls for government water managers and private water companies to "stem the drain on America's water resources before it's too late."
December 17, 2010, 11am PST
This collection of photographs from <em>Smithsonian</em> documents the construction of the recently opened bypass bridge at the Hoover Dam.