10 Alternative Fuel Ideas That Never Made It Out of the Lab

Could you use cat corpses to fuel your vehicle? If you could, would you want to? A German newspaper reported in 2005 that an inventor had developed a fuel system that could be powered by garbage, including deceased felines.

The story, soon picked up by Internet news sites, included the gruesome fact that a full tank of fuel would require 20 cats. The article even offered some comments from at least one outraged animal rights supporter.

Like many bizarre stories, this one had a grain of truth. Dr. Christian Koch did indeed invent a machine that can convert garbage such as paper, plastics and yard waste into biodiesel fuel. There was no mention of cats, however. The whole dead-cat angle was apparently invented by a ghoulish, but creative reporter. Koch's KDV 500 device can supposedly turn trash into gas at a steep discount compared to prices at the pump [source: Deutsche Welle].

Like many claims of revolutionary energy sources, we're still waiting to see the results -- dead cats excluded.

Up next, an idea for an alternative fuel that some people may find difficult to part with -- especially on a hot summer day.

Well, it's not exactly beer, but this is a fuel you can brew yourself.

Ethanol can be made by fermenting sugars, similar to whiskey. It's possible to run a car on pure ethanol -- in fact, all of the race cars in the Indy Racing League use it. So why not buy some sugar and set up your own backyard gas pump?

The idea itself isn't inherently bad. It may be a good answer for certain individuals, and improvements in technology are making ethanol easier to produce at home; however, there are still a few reasons why this won't work on a large scale. The economics just don't work out.

Using the United States as an example, the sugar that's available is just too expensive to make this a worthwhile endeavor. In addition, distilling ethanol in your yard requires special permits, and it isn't currently legal to run a car on pure ethanol in the U.S. -- home distillers are required to make a fuel blend to stay on the right side of the law [source: Fitzgerald].

The biggest problem might actually be the effort involved. A certain segment of the population is highly motivated and technically skilled, and they'd love the thought of brewing their own fuel. But for this energy source to go mainstream, the average soccer mom has to be willing and able to tackle the process, too.

We're not picking on soccer moms here, but any fuel source that requires more effort than plugging-in to a wall outlet or filling-up at the pump is going to face an uphill battle for widespread acceptance.

Despite what you may be thinking, there are a few alternative energy sources that have a real shot at changing the world -- they're just a little unusual. But then again, that's why you're reading this article, right?

This idea might sound outlandish - how could we generate enough sawdust to generate a useful amount of energy? The average U.S. saw mill processed 7.1 million board-feet of lumber in 2001 alone [source: Bowe, et al]. Multiply that by the number of mills worldwide, and we're talking about a lot of sawdust.

All the waste material from industrial wood processing is generally discarded, and we're talking tons of wood waste here. Some of it's reprocessed into particle board or into wood pellets for stoves, but there's still a lot of unused waste wood out there. When left to rot, wood waste is actually an environmental hazard that generates methane, a harmful greenhouse gas.

One solution is to ship the sawdust to a power plant designed to burn it. The heat is used to generate electricity. The idea is more than feasible, it's already in practice -- a 14-megawatt wood waste power plant is being built in Nigeria. Sawdust from nearby mills will be shipped to the plant, and the electricity generated will in turn be used to power the wood mills, with enough energy left over to sell to the national power company [source: Energy Resource].

The next alternative fuel idea will probably make you wrinkle up your nose, but Canada is willing to give it a go. Why shouldn't you?

This one sounds almost as gross as dead cats, but used diapers could be an excellent fuel source -- not that anyone would want to live downwind of the power plant. It's possible for garbage to be turned into fuel gas and fuel oil with very little pollution by using a process called pyrolysis. It differs from incineration in that the material is heated in a sealed, oxygen-free environment, which breaks down the molecules inside to create useful byproducts.

Why do diapers make such good candidates for pyrolysis? There are several reasons. For one, we have a lot of disposable diapers, and we (as in, babies) constantly generate more. The second reason is that it would be relatively easy to use special recycling bins to separate them from other garbage.

The third and final reason is -- and really, this is the biggest reason it would work -- consistency. Pyrolysis works best when it has been fine-tuned to the material being heated. Mixed garbage is full of all kinds of random materials, and you never know what sort of mix you're going to get from one day to the next. We know exactly what's in diapers, that is, in terms of the plastics and fabrics used in their manufacture, as well as what's in diapers, in terms of what babies put there.

So what's the end result of taking in dirty diapers for finely tuned pyrolysis? Fuel products, of course. A power company in Quebec, Canada is planning a plant to test the technology [source: Hamilton].

If someone suggested you could power all the electric devices in your home with paint, and then you compared the price per-gallon of paint to fuel, you might think this idea is short-lived. But this isn't paint you burn as fuel -- it's a special solar paint that captures the energy of the sun.

Swansea University engineers are working on what is essentially a paint-on solar panel that can be applied to the steel panels used to cover many buildings. The interaction of the sun with the paint and the underlying steel surface creates a current that can be captured and diverted.

Taking into account the huge amount of square-footage available, and using a relatively modest 5 percent conversion rate for available solar energy, the scientists calculate that annually the solar paint could produce the energy of 50 wind farms in Britain alone. And that's even considering the level of sunlight Britain receives -- not much compared to places like Arizona or Kenya [source: Science Daily].

This is a technology that has kinda, sorta, almost made it out of the laboratory. But when you read more about it, you'll wish it stayed there.

Indian car company Tata Motors (who now own Jaguar and Land Rover, in a nice reversal on British colonialism) has been working for years to develop and market a car that runs on compressed air. Here's how it works: a tank full of compressed CO2 sprays out air, driving a tiny piston engine that turns a crankshaft and drives the wheels of a small, lightweight car.

Tata Motors has the license to technology crafted by a French company called MDI, which has been developing compressed air as an alternative fuel since the early 1990s. They've been plagued with numerous setbacks, however, including lawsuits and a failed almost-launch in 2010.

The company said recently that they're closer than ever to getting a compressed air car on India's roads. The good news? No emissions, and obviously, no dependence on fossil fuels. The bad news? It's going to be slow. Like, really, really slow. Expect power and torque to be in the single digits, and for top speeds to be around 30 miles per hour. Its range is extremely limited as well. Maybe Tata's next project will be a car that a human being can't outrun during a brisk jog.

Remember the 1996 Keanu Reeves film "Chain Reaction?" No? Well, you're not the only one. But here's the part that's relevant to what we've been discussing: the movie is about a team of researchers trying to create energy from water. (Also, Rachel Weisz is in it, and there's nothing wrong with that.)

Fans of the movie, all four of them, have long wondered: Why haven't scientists found a way to extract energy from water? The truth is, they've been working on it. In 2007, an inventor found a way to ignite salt water using radio waves. That scientist, John Kanzius, who was actually working on a technique to fight cancer, discovered that the heat from the ignited water could power a small engine [source: Stroh]. In other words, the concept has been proven that salt water is a potential power source, but development of this idea hasn't progressed very far.

At least one other scientist claimed to have developed a car that could run on water. In the mid-1990s, inventor Stanley Meyer said he created a "fuel cell" that ran on water. However, the scientific community debunked Meyer's claims, and he ended up getting sued by his investors, during which he was declared a fraud by the courts. Maybe there's someone else out there that can truly make water work as a fuel.

If there's anything we humans are exceptionally great at, it's making garbage. No, we're not talking about Keanu Reeves movies again. We're talking about the stuff that's filling up your trashcan. In general, we're a wasteful society, and we don't think twice about throwing things away when we're done with them.

But what if trash could be used as a fuel source? Actually, some scientists say it can. Landfill gas, also called biogas and biomethane, is one of the few ideas on this list that's getting pretty close to being "out of the lab." While it's a relatively new technology, it's becoming increasingly popular in the U.S. and other countries because it's renewable -- and because there's no shortage of garbage on our planet.

As trash sits in landfills, the organic materials break down over time, creating methane and other gases. The landfills are covered up, and those gases are compressed to be used as a fuel source. Several corporations have begun to look for ways to use biogas to power their operations. Most recently, Apple has said biogas will help power a fuel cell farm at one of their centers in North Carolina [source: Gigaom]. It's about time we found something useful to do with all of our trash.

Not all of the alternative fuel sources on our list are disgusting like the dead cats and landfill trash. Who doesn't love chocolate? Perhaps at some point in your life, you've been indulging in a Hershey bar or some rocky road ice cream and said to yourself, "You know what would make this even better? If I could run my car off of it."

Perhaps that same thought is what led scientists at the University of Warwick in Britain to create a Formula 3 racecar that runs on the waste byproducts created when chocolate is made. "Anything with a fat in it can be turned into diesel, and that's what we've managed to do," project head James Meredith told the New York Times in 2009 [source: Motavalli].

The fuel they used comes from the Cadbury's factory in England, making research for the car extra delicious. It's a good example of how nearly anything can be used to create biodiesel fuel.

Interestingly enough, their F3 racecar was made almost entirely out of recycled and plant-based organic materials. Your fancy-pants Prius doesn't look so green now, does it?

One of the most promising fuels on this list doesn't come from our kitchen, trashcan or litter box like the rest; it comes from the bottom of the sea.

Scientists across the world have been working hard at getting algae-based fuels out of the laboratory and into power plants that could light and heat our homes. Algae can be used to create biofuels with the potential to augment and replace our existing fossil fuel supply. Oil is harvested from the algae cells through a variety of methods; those oils are then mixed with other chemicals to create biodiesel. The good news about algae is that it can be easily grown in a tank.

In other words, what we have here is a truly viable renewable energy source. It's far superior to corn when it comes to producing fuel and doesn't threaten our food supply. Both government and private money has been invested heavily in algae fuel research.

But algae fuel development remains in its very early stages; that's why this one hasn't made it out of the lab. At least, not yet -- one recent study says algae fuels are at least a decade away from marketability [source: Keune]. Still, it's one of the more promising alternative fuel ideas out there -- and it doesn't even smell like dirty diapers.