Minimizing the armed forces' dependence on oil saves soldiers' lives and the move towards renewables is a lifeline like no other for the green energy industry. (Click the image for more information.)
NEW YORK (CNNMoney) -- One out of eight U.S. Army casualties in Iraq was the result of protecting fuel convoys.
This statistic, derived from an Army study looking at fuel convoys in Iraq from 2003 to 2007, is a powerful incentive for the military to move away from oil and toward renewable energy, and that's exactly what it's doing.
From experimental solar-powered desert bases for the Marines to Navy robots that run on wave energy, the military is quickly becoming a leading buyer of cutting-edge renewable energy technology.
For the armed services, the benefits extend beyond reducing fuel convoy casualties. A fighting force that isn't restricted by the reach of a tanker truck or weighted down by heavy batteries is more nimble and, as a result, more lethal.
For renewable energy companies, the military is proving to be a vital customer, buying the latest in clean energy gadgets and encouraging private investment. The hope is the armed services can shepherd this technology to the point where it becomes commercially viable, much like it did a generation ago for GPS systems or the Internet.
"Some people might get the impression they're throwing away money because some stuff doesn't work," said Rachel Sheinbein of CMEA Capital, a venture capital firm that invests in renewable energy companies. "But the ones that do work, the differences they make are huge."
A solar desert base: A hundred and fifty miles east of Los Angeles, the Marines are trying to figure out what works for them.
This week is the second year in a row the Marines have constructed an "ExFOB" at the Twentynine Palms base deep in the California desert.
Short for Experimental Forward Operating Base, the Marines are trying to see what devices can turn the most remote of military outposts into self-sufficient encampments.
Being energy self sufficient in places like Iraq or Afghanistan isn't just a tree-hugging point of pride. These bases currently use diesel or other fuels to run generators that power everything from air conditioning in tents, to computers running battlefield management software.
Fuel in Iraq generally arrives at big bases via tanker ships. The military didn't release specific statistics about convoy deaths in Afghanistan. But the logistical challenges there are huge.
Fuel in Afghanistan is delivered via truck convoy from Pakistan to distribution centers. Other truck convoys then redistribute the fuel to smaller bases. All these convoys are big, slow-moving, explosive targets.
In some cases fuel has to be helicoptered in. In addition to risking lives, that's also pricey. The military says it can cost up to $40-a-gallon to get fuel into the most remote and dangerous places.
Last year, the Marines bought solar panels that roll up like beach mats and can be stuffed into backpacks. During tests in Afghanistan, the mats were instrumental in reducing the number of batteries the Marines had to carry to run radios or laptops.
This year the Marines are looking to buy larger, trailer-mounted solar panels that use advanced materials to generate twice the power of conventional silicon-based panels and can power an entire base. They are also testing fuel efficiency devices for their tactical vehicles. Ultimately, they hope to cut their fuel consumption 50% by 2025.
Efforts like this are happening across the armed services, driven both by tactical concerns and mandates from Congress and the president.
The Navy is experimenting with a surfboard-shaped, wave-powered robot from a company called Liquid Robotics that can be used to monitor the high seas at a significantly cheaper price than using a ship.
They Navy is also experimenting with wave and tidal power devices, as well as using advanced biofuel to power its boats. The Air Force has long used biofuels as part of its fuel mix in planes, including second-generation fuels from algae and other plants that people don't eat.
"We view ourselves as a target-rich environment," Secretary of the Army John McHugh said last week in announcing plans to provide wind and solar developers with Army land and long term agreements to buy their electricity. The Army aims to get 25% of its power from renewable sources by 2025.
McHugh noted that the military accounts for 80% of the federal government's overall energy use and spends $15 billion a year on fuel.
"This is the right thing to do for the environment, for the taxpayer and, most important, the right thing to do for our soldiers," he said.
Sentiments like this are becoming increasingly common among military men and women -- a crowd not often thought of as the vanguard of the green energy movement.
An executive from one of the world's largest wind turbine builders recently told CNNMoney that militaries the world over go to great lengths to accommodate their turbines near bases, even though they have a tendency to interfere with radar.
One Army medic returning from Iraq recently switched his home to solar power. He said the amount of fuel he saw the U.S. military consume in Iraq was a driving factor.
"It would be naive to think that some of the money we spend doesn't find its way into the bad guys' hands," said Patrick Padilla, who saw heavy fighting in the Iraqi city of Ramadi in 2006. "If I can do my part to cut that down a little bit, then that's hopefully one less person getting shot at, like I had to go through."
And Pentagon strategy papers have identified energy and resource conflicts as a prime driver for future wars.
Whatever the reason for this interest in clean energy, it's a boon for companies in the alternative energy space.
The golden customer: One of the biggest challenges for renewable energy firms, often small start-up companies, is credibility.
"Having the military buy these systems proves they are reliable," said Ron Helfan, an executive with Israeli-based Essence Solar Solutions that's trying to sell an advanced solar power system to the Marines known as the Sun Spider.
Alan Salzman, co-founder and CEO at VantagePoint Capital Partners, agrees.
Salzman should know -- his firm reviews pitches from thousands of renewable energy companies and decides which ones to fund.
"The military is a great reference customer," he said. "Just as good as any Fortune 100 company."
The military also plays an important role in buying technologies that are currently too expensive for the general public.
It's not that the military likes to waste cash. It's just that its world lends itself to a different set of cost-benefit calculations than civilian life -- think of the lives lost protecting fuel convoys and the $40-a-gallon price tag.
The hope is that the military can buy these items and support the industry until further cost breakthroughs are made and the devices have wider commercial appeal.
For Salzman, the military and renewable energy companies that's what it's ultimately all about -- designing and building products that make sense from a financial and operational point of view, whether that's for today's military or tomorrow's civilians.
"This isn't about wearing hemp and walking to work," he said. "This is about finding better ways of doing things." 
