Pentagon could save lives by cutting fuel use-study

* Fuel convoys make troops vulnerable

* Casualties in Afghan war could more than double

* Big opportunity for defense companies

By Andrea Shalal-Esa

WASHINGTON, Nov 10 (Reuters) - The Pentagon could save lives and money by cutting its use of fuel and developing more alternative sources of energy, according to a new report released by the consulting firm Deloitte LLP.

This "national imperative" could also be a huge opportunity for U.S. defense and aerospace companies at a time of mounting pressures on the U.S. and global defense budgets, said Charles Wald, a retired U.S. Air Force general, senior adviser for Deloitte and co-author of the report.

Lockheed Martin Corp (LMT.N), Northrop Grumman Corp (NOC.N), Boeing Co (BA.N) and other big defense companies have already begun highlighting their work on alternative energy technologies and ways to improve energy efficiency.

Failure to change the Pentagon's approach could more than double the number of U.S. troops killed in Afghanistan by 2014, the report warned. More than 900 U.S. soldiers have been killed in Afghanistan since the U.S.-led invasion in 2001.

The report said developing and using alternative energy should be seen as a priority on a par with Pentagon efforts to develop new weapons, mine resistant armored trucks and sophisticated new sensors.