Sen. Mark Udall (D-Colo.) and Rep. Scott Peters (D-Calif.) announced a bill Wednesday to push military operations to be more energy efficient and rely less on fossil fuels.

Udall and Peters said the military’s use of fossil fuels represents national security and operational challenges. Their measure would also save money that could be put into other places in the Department of Defense and improve the military.

“Every fuel convoy on the roads Afghanistan places our men and women in uniform at risk,” Udall told reporters Wednesday. “We’ve suffered over 3,000 casualties in attacks on these covoys since 9/11.”

Improving the efficiency of vehicles and generators would reduce the need for fuel convoys and reduce troops’ exposure to harm, Udall said.

In another example of a provision in the bill, Udall said developing lighter batteries would reduce the load troops have to carry.

Udall and former Rep. Gabby Giffords (D-Ariz.) had worked on military energy efficiency proposals for years, and Peters began to work with Udall when he was elected in 2013, after Giffords had resigned. Some of the ideas have been put into law, including mandating that the military buy biofuels.

The bill announced Wednesday, called the Department of Defense Energy Security Act of 2014, focuses on a few major places where energy is consumed in the military.

It would authorize mobile energy-saving performance contracts, in which private companies would build efficiency projects in places such as ships and generators.

The measure would establish opportunities for military-wide cooperation on efficiency, like a database of projects and encourage vehicle efficiency research and allow investment in fueling infrastructure for alternative-fuel vehicles.

Peters said his communications with military leaders show that they want the provisions in the legislation.

“Military reliance on fossil fuels is a national security issue,” Peters said. “And the wars in Iraq and Afghanistan showed us the problems we have with fuel convoys and supply line vulnerabilities.”

Udall said he and Peters will try to get the energy efficiency measures inserted into the next annual National Defense Authorization Act.