Speaking at an Environmental Defense Fund reception May 2, Defense Secretary Leon Panetta said that higher than anticipated fuel costs are causing a budget shortfall of more than $3 billion at the agency as the Pentagon seeks billions of dollars in new energy efficiency spending. The measures, which range from energy-efficient aircraft engines to ships with hybrid electric drives, are included in the agencyʼs $614 billion fiscal year 2013 budget request. The request includes $1.4 billion for operational energy enhancements that will improve energy efficiency, including over $268 million for efficient aircraft and aircraft engines and $255 million for combat vehicle energy efficiency. The agency is also requesting $1.1 billion for energy efficiency improvements such as lighting retrofits and boiler plant upgrades at its 300,000 existing buildings. The Defense Department, the countryʼs largest energy consumer, spent $15 billion on fuel for military operations last year.