Facing a Friday deadline, the U.S. Energy Department has approved two loan guarantees worth more than $1 billion for solar-energy projects in the western states of Nevada and Arizona. Energy Secretary Steven Chu said the department has completed a $737 million loan guarantee to Tonopah Solar Energy for a 110 megawatt solar tower in Nevada and a $337 million guarantee for Mesquite Solar 1 to develop a 150 megawatt solar plan in Arizona. The loans were approved under the same program that paid for a $535 million loan to Solyndra Incorporated, a now-bankrupt solar-panel maker. The latest loan program, approved under the 2009 economic stimulus law, expires Friday. At least seven projects worth about $5 billion are pending.