[ASSURAS] The high gas prices we're seeing across the country are causing a lot of frustration, and, not to make you even more angry, but here goes -- did you know that only about 15% of that liquid gold actually spins the wheels? Sad but true. Combustion engines are so inefficient that the rest -- 85% -- is lost as heat or friction. Still, there might be some changes coming for vehicles, and trains, too. New technologies that capture the energy of motion. More from "energyNOW!"'s Josh Zepps in this energyNEXT.

[ZEPPS] Have you ever been on a train and accidentally spilled your coffee on a total stranger? I know I have. It happens because the train moves around in all kinds of ways that have nothing to do with actually getting you where you want to go. But imagine if we could harness all this kinetic energy and use it to light the train's lights and maybe even brew more coffee to throw on yet more strangers? Would you like that idea, huh?

Kinetic energy is the energy of motion. We generate a lot of it in this hectic, modern world. And almost all of it goes to waste. But a new class of crafty kinetic capturers is changing that.

Philadelphia's metro system is run by SEPTA, the Southeastern Pennsylvania Transportation Authority. Chief Power Officer Andrew Gillespie wanted to save a buck on the $12 million in electricity his trains guzzle every year, so he modified the train's brakes to generate electricity as they slow down.

[GILLESPIE] We probably use 30% of the regenerated power. Existing trains can use it to power lights, heaters and such.

[ANNOUNCER] Doors are closing.

[GILLESEPIE] What we want to do now is take that energy, which is electricity, send it back through the power distribution system, which supplied the power to the train in the first place, and store it.

[ZEPPS] That's the key -- storing it. See, normally, when you capture a train's kinetic energy, you can either use it to power onboard systems or feed it back into the supply system to be sucked up by another train that needs it in that same split second. But, if it isn't used instantly... it's gone.

So, in this cavernous room at the Letterly Power Substation, SEPTA is installing an enormous 1,000-kilowatt battery to store the energy harvested from its braking trains. Whenever it's needed, that stored energy can be sent to other trains, reducing energy waste, reducing costs, and reducing emissions.

Is this kind of technology going to be widespread through transit systems in the United States?

[GILLESEPIE] I'm sure it will be. We're not the only ones who are looking at this. It's a technology that's just in its infancy, but there's so much power that's not being captured right now.

[ZEPPS] Now, stopping and starting are not the only ways we waste kinetic energy. Any time you move fast over an unsmooth surface, you bounce up and down. Vehicles are bumpy -- it's why shock absorbers were invented. And now they're being reinvented by a pair of kinetically inspired M.I.T. grads at Levant Power in Massachusetts.

[SHAKEEL AVADHANY, CEO, LEVANT POWER] Essentially, what we do is, we generate electricity from bumps in the road. We use electricity for fuel economy gains.

[ZACKARY ANDERSON, COO, LEVANT POWER] The system works by actually shuttling fluid through a hydraulic motor that spins a generator. So as your wheel moves up and down, it spins an electric generator, and that generates electricity.

[ZEPPS] Electricity that can power the vehicle's headlights, stereo, GPS, butt-warmer in the seat if you're lucky -- all things that would ordinarily drain power from the engine. They call this shock absorber "GenShock," and its output ranges from tens of watts to several kilowatts. That translates to gas savings of 1% to 5%, depending on the type of vehicle and terrain.

This is mimicking the motion of a road. As you drive faster and go over all kinds of potholes, this is generating power, which is going to a bank of lights behind me that you can see flashing. When the car's going really fast... you can almost have a rave.

Of course, the heavier the vehicles, the bigger the energy return. So Levant is getting a lot of interest from heavy fleet operations.

[ANDERSON] So we're working with the U.S. Army, and they shipped us a military Humvee, an 1152, that we're actually doing an installation on, so we have the Humvee out back.

[ZEPPS] You have a Humvee here? Wow.

[ANDERSON] Yep.

[ZEPPS] It's amazing to think that this could be the prototype vehicle from which all of the Army's Humvees could be fitted so they need to use less power, less energy, be more efficient, and also a nicer ride, which would be nice -- this is no Lexus.

And in the context of capturing energy, that's a good thing. The beauty of kinetic energy is that, because it's everywhere, you can capture it in myriad ways. If you're dealing with urban rail, which stops and starts all the time, harness the brakes. If you're dealing with a workhorse that bounces along rough terrain, harness the shock absorbers. The modern world's incessant bouncing, braking, and bumping is an almost unlimited energy source going to waste right under our nose. Thankfully, not for much longer.

[GILLESPIE] I think when we look back on it, we're going to realize how inefficient we were.

[AVADHANY] At some point, it will be illegal to waste energy as heat.

[ZEPPS] But don't go using GenShocks as a reason to get a Hummer. I'm just sayin'. [Alarm chirps] In Cambridge, Massachusetts, Josh Zepps, "energyNOW!"

[ASSURAS] Levant Power expects to have a product on the market in 2012 and tells us that it has also figured out how to use some of GenShock's power for a smoother ride and better handling performance, so, you can save on gas and prevent coffee spills.