ABOARD THE USS KEARSARGE — A gasoline-powered generator can supply electricity to a remote U.S. Marine outpost in Afghanistan, powering everything from laptops to communications equipment.

And the noise from that generator can be a dead giveaway to Taliban forces searching for Americans.

So when Marines tout the effectiveness of quiet, solar-powered generators, it's not because they feel all warm and fuzzy about Earth Day. They say the equipment makes them safer in a combat zone.

These battlefield realities — along with concerns about the budget — stood front and center Monday as a Senate panel convened in a rare setting to highlight energy efficiency goals now being pursued by the Defense Department.

For the first time since 1960, a U.S. Senate panel met onboard a U.S. Navy ship — the amphibious assault ship USS Kearsarge, which was pier side at Naval Station Norfolk. The event featured Virginia's two famous Warners: Sen. Mark Warner, who asked questions, and former Sen. John Warner, also a former secretary of the Navy, who testified.

There were no decisions made, no votes taken. It was the Senate Energy Committee's sub-panel on water and power. Sen. Jeanne Shaheen, D-N.H., chairs the subcommittee, and she invited Sen. Mark Warner to ask questions as well, although Warner is not a member of that particular panel.

Rather than votes, it was a day set aside to talk about energy conservation projects being undertaken by the Navy and Marine Corps, an effort that has generated some controversy about the military's priorities.

The selection of the Kearsarge was no accident.

It is the first of the Navy's big-deck amphibs to employ a stern flap, which acts in a similar manner to an air foil on the back of a sports car. In this case, a ship moving faster through the water tends to rise in the front, the bow. The stern flap in the rear of the ship, which rides underwater, lowers the bow and positions the ship more parallel to the water.

It sounds simple, but the savings have been undeniable, according to Cmdr. Jerry Chapmon, chief engineer on the Kearsarge. The stern flap has paid for itself in a year by saving on fuel. The Navy estimates it will save $1.1 million per year, per ship. Other amphibious assault ships will receive the stern flap when they go into the yard for extended work.

Not just money

But military leaders said cost savings are not the only motivation. That's why the solar powered generators are a hit.

"A lot of our enemies can follow us around by the noise of our generators," said Marine Col. Bob Charette, director of Expeditionary Energy in the Marine Corps. "Marines start using this, and they believe it scares the bad guys because they can't hear where we're at — because there's no generator running. Normally, you can find Americans on the battlefield by their generators."

Solar-powered generators result in fewer convoys to deliver fuel. Charette said Marines like the solar units because they don't have to call for supplies as often, and they have more time to focus on the enemy.

Charette spoke against the backdrop of a display that included the solar panels – which could fold up into a suitcase-like container – as well as batteries and chargers. It was among several displays set up in the lower deck of the Kearsarge.

Not everyone in Congress is pleased with portions of the Defense Department effort. That includes Rep. Randy Forbes, R-Chesapeake, who recently scolded Navy Secretary Ray Mabus in a congressional hearing in Washington, D.C. Forbes is particularly concerned about an emphasis on biofuels, which are more costly to make than fossil fuel. Forbes said the Navy should spend its limited funds on more ships, aircraft and other necessities.

Mabus also testified Monday, and he was asked directly about that issue while meeting with reporters.

Navy has led the way

The secretary said the Navy has a history of leading the way in energy innovation, from sails to coal to oil to nuclear power. Some people questioned it along the way, but they were wrong.

Second, he said pitting energy projects against money for hardware is "a false choice." Without a reliable, economical source of energy, Navy ships and other tools of war will be less effective. The two go hand in hand.

Sen. Mark Warner commended Mabus during the meeting.

"I don't understand how some members of Congress just don't get it," he said.

Many initiatives save both lives and money. Take the solar-powered generators, which are more expensive up front than old, fossil-fueled machines. Charette said the investment will pay for itself. Marines pay about $8.30 per gallon for fuel in Afghanistan, which is bought from NATO in the western part of Helmand Province.

"You'll get a payback on it," he said. "But this is about saving lives, not money."

John Warner heartily endorsed the Defense Department direction, especially when it came to biofuels. Since leaving the Senate, he has been involved with the Pew Project on National Security, Energy and Climate.

"America's military preparation, for the present and future, is predicated on innovation," he said.