General Motors said Thursday that it is collaborating with the U.S. Navy to incorporate automotive fuel-cell technology in future unmanned underwater vehicles.

This is the automaker’s second recent collaborative effort with the U.S. military. Last November GM and the U.S. Army signed a contract to build and demonstrate a fuel-cell reconnaissance vehicle for the U.S. Army Tank Automotive Research, Development and Engineering Center (TARDEC) in Warren, Mich.

None of GM’s brands have a fuel-cell vehicle on the market yet, but the company has been working on the technology for years. In 2008, GM launched a three-year trial by outfitting 100 Chevy Equinox sport-utility vehicles with hydrogen tanks and a fuel cell powertrain.

Hydrogen fuel cells convert high-energy hydrogen efficiently into electricity, providing an alternative, zero-emission power source to vehicles. Under the Office of Naval Research’s Innovative Naval Prototype program for unmanned underwater vehicles (UUVs), energy is a core technology in the Navy’s goals for vehicles with more than 60 days of endurance.

The Naval Research Laboratory recently concluded an evaluation of a prototype unmanned underwater vehicle equipped with a GM fuel cell at the heart of the vehicle powertrain. The tests, a key step in the development of an at-sea prototype, were conducted in pools at the Naval Surface Warfare Center in Carderock, Md.

“Our in-water experiments with an integrated prototype show that fuel cells can be game changers for autonomous underwater systems,” said Frank Herr, ONR’s head of Ocean Battlespace Sensing.

Hydrogen fuel-cell propulsion technology helps address two major automotive environmental challenges. It reduces oil consumption and carbon dioxide emissions. Fuel-cell vehicles operate on hydrogen from wind and biomass stored for later use. Once converted to electricity, water vapor is the only emission. Recharging takes only minutes.

GM’s fuel cells are compact and lightweight, and have high reliability and performance. Lower cost is achievable through volume production. These attributes match the goals of the Navy to develop reliable, affordable systems.

“The collaboration with the Navy leveraged what we learned in amassing more than 3 million miles of real-world experience with our Project Driveway fuel cell program,” said Charlie Freese, executive director of GM global fuel cell activities. “Our customers will benefit from additional lessons we learn about the performance of fuel cells in non-automotive applications that will be useful in GM’s drive to offer fuel cells across consumer markets.”