Archive for the ‘compressed air’ tag

Alternative Fuel Technologies – A look at the major contenders

With gas prices having hit $4/gallon and with no relief in site, I think we’re all looking for alternatives so that we’re no longer dependent on the volatile oil market. There is a lot of talk about alternative fuels these days so I thought I’d take a few minutes to give you the lowdown on the major contenders to replace to replace the gasoline currently swishing around in your tank.

So let’s take a look at the four alternative fuels most likely to take over as the dominant fuel in your vehicle.

Electricity

We use electricity to power just about everything else so why not your car? Just add a few more batteries and you’re good to go, right? Well, sort of.

Advantages of electric cars

Electric cars have a lot of advantages. First there’s that whole no emissions thing. Just think about how that would help with smog in major cities. Some will argue that since in the United States most of our power comes from coal, it’s just switching from one fossil fuel to another, and they’re partly right, but they’re missing the point.

The power grid gets cleaner every decade. Right now billions are being invested in both solar and wind power so your electric vehicle actually becomes a “greener” car to drive the longer you drive it.

Also, keep in mind that electricity generated at power plants is generated far more efficiently than in an internal combustion engine. Even if it does happen to be from coal or natural gas, it’s still cleaner than burning gasoline in your car’s engine.

Also, keep in mind that reducing our dependency on foreign oil is just a smart thing to do.

One of the really cool things about an electric car is never having to visit the gas station. A fully electric vehicle can be charged from a standard 110v outlet in your home in just a few hours.

Disadvantages of electric cars

With the numerous advantages that electric cars have to offer, it’s not without its fair share of downsides.

Probably the biggest concern right now is the lack of range with electric vehicles. GM’s Volt line is expected to come out in 2010, but those cars are only expected to have a range of 40 miles before the gasoline engine needs to kick in. That’s enough for your daily commute or running errands around town, but not much else. 100% electric cars (i.e. – no hybrid gas engine or alternative fuel source) such as those made from companies like Tesla fare better with a range of about 200 miles, but that’s still far below a typical gas powered car even if it is a gas guzzling SUV.

Then there’s the whole issue of how long it takes to “refill” or in this case recharge. Current lithium batteries are going to take 4-6 hours before they’re fully recharged. Again, not a problem if you plug it in for the night, but not a whole lot of fun if you’re driving across country on a road trip.

Then there is that little nagging issue of where we’re going to get all that power. Let’s face it, the power grid in the United States is already stressed. If we all switched over to electric vehicles, we’d crush it. We would have to build a lot more power plants which would likely be fossil fuel burning plants like coal and natural gas to cope with the extra demand placed on the grid. It’s good for reducing our dependency on foreign oil, but still not exactly a “green” option… at least not yet.

Infrastructure

While it’s easy to say that the infrastructure is in place for electric vehicles, that’s just not true yet. I know I’m going to sound like a broken record here, but we simply can’t crank out enough power right now to just switch to electric. Refineries would have to be replaced with power plants.

However, one company has a novel solution where for an extra $20k they’ll install solar panels on your roof which will provide plenty of electricity for you to electric car.

Then there’s that whole recharing ordeal. Nobody wants to hang out with “Daryl” the gas station attendant for four hours watching tumbleweeds blow by while the batteries on the electric car recharge. I’ve seen some research from some of those MIT geniuses about carbon nanotube capacitors that can be recharged in seconds, but they’re still little more than a glimmer in the theoretical physicists’ eye – cool if it can be commercially viable, but still a big question mark.

Until the recharging issue is solve, electric vehicles are unlikely to be more than a niche player in the alternative fuel game. Electric vehicles will likely need to be paired with another kind of fuel for the foreseeable future to make them practical.

Hydrogen Fuel Cells

Hydrogen fuel cells have been looked at as the fuel of the future for decades now.

What’s so great about running a vehicle on hydrogen? Easy, when burned in a fuel cell engine, the only emission is water vapor – you could put the water in a glass and drink it.


Advantages of hydrogen fuel cells

Hydrogen is abundant – in fact it’s the most abundant element in the known universe. On Earth it doesn’t float around as hydrogen all that readily, but through electrolysis it’s pretty easy to get all the hydrogen we’ll ever need from water. And since it goes back to water when it’s used, it’s not like we’re using up the water either. This is one fuel source we’d never run out of.

It’s also a highly efficient fuel. Hydrogen has the highest energy content per unit of weight of any known fuel.

Disadvantages of hydrogen fuel cells

Hydrogen also comes with its own list of drawbacks though. In this case, the major issue is storing the stuff. If you want enough hydrogen to power your vehicle, you’ve got two choices, compress it or make it cold until it turns into a liquid. If you can make it a liquid, you can store a lot more of it in a tank, but hydrogen doesn’t become a liquid until you get down to -252.87 Celsius (-423.17 Fahrenheit). That’s darn cold! And keeping it that cold requires a pretty significant amount of energy. Compressing it is currently a better choice, but it requires larger storage tanks (which increase weight).

The other disadvantage of hydrogen is that it burns so efficiently (yes, I know I said that was an advantage) – so efficiently that it’s keen on blowing up as any Hindenburg aficionado is well aware. But then again, gas blows up too, so you won’t actually be driving a 70mpg 2,000lb missile down the Interstate anymore than you are now.

Infrastructure

I was reading an article a few days ago that said the cost of getting an infrastructure in place would require somewhere in the neighborhood of $70 billion in subsidies. We have a massive network of gas stations that would need retrofitting with tanks to store hydrogen, but the bigger issue is making hydrogen on a massive scale. We don’t really have that.

Hydrogen has a lot of promise as a fuel, but it’s probably the furthest away from reaching its potential as a fuel.

Compressed Air

Compressed Air is a perfectly viable alternative fuel that you really don’t hear much about.

For those of you who took an Industrial Arts class (shop class) in high school, you’ve probably built your own version of an air powered car using some balsa wood and a CO2 canister, but for those not so cultured, here’s a Youtube video showing these fun little toys (I’d make my own video, but mine was reduced to splinters in a crash.)

[youtube J6Jq-0Ou0Dg]

So if you think about it using compressed air to, say, turn some pistons in an engine and make it run wouldn’t be too terribly difficult either.

All you need is a tank with enough air in it and you’re good to go.

Advantages of compressed air

The more I think about compressed-air cars, the more excited I get. Let’s talk about the fuel source first. It’s air – the same stuff we breathe. You fill up your tank with an air compressor – that’s it – you’re done.

Now let’s talk about emissions. It uses compressed air. When you uncompress air, it’s just air – the same stuff it was before you put it into a tank in the first place. That means zero emissions.

Unlike with electricity which takes hours to recharge, it only takes about three minutes to fill up your tank with a service station air compressor. It’s been estimated the cost would be about $3 to fill ‘er up for a full tank of air. The cool thing is that a lot of air vehicles are being made with on board compressors so you can plug the unit in your standard plug at home and the tanks will full recharge in about 4 hours. It’s like getting all the benefits of electric without the drawback of not being able to recharge quickly.

Lastly, compressed air vehicles can be significantly cheaper than their gasoline powered counterparts. While most alternative fuel vehicles add a significant chunk of change to the final price of your vehicle, air powered cars are actually cheaper.

Disadvantages of compressed air

While compressed air may sound like a pretty sweet deal, it does have a few drawbacks. So far all compressed-air cars have been small, and they are made out of aluminum, not steel to save on weight.

Also, the current range of 100% compressed air vehicles is only a little over 100 miles at the moment which makes them impractical for long trips. The American company Zero Pollution Motors plans to release their vehicle as a compressed air hybrid which also comes with a conventional gas engine which can actually extend the range of the vehicle to 800 miles.

Infrastructure

If compressed air vehicles did start to catch on, the infrastructure changes would be relatively minor. Refueling stations would need to invest in pumps that dispensed compressed air instead of gas which wouldn’t be too difficult. My guess is the hardest part would be for the government to figure out how to tax it.

Since it uses just air, no refineries would need to be built – air is freely available all around us. We just need to bottle it up and it’s ready to go.

Biofuels

I’m lumping all of the biofuels into this category. I’m talking about ethanol (whether its made from corn, sugar cane, kudzu, switchgrass, or algae really doesn’t matter) and biodiesel (made from vegetable oils).

Advantages of biofuels

The advantages of biofuels are that they’re something we’re already familiar with. You fill up your tank with a liquid that gets squirted into a little chamber and it burns making those ponies under the hood make those noises that get teenage boys all hot and bothered.

There’s also that whole “foreign oil dependency” thing. I don’t know about you but giving billions of dollars each year to countries that hate us and want all us “infidels” to die a slow and painful death really doesn’t bring visions of sugar plums dancing in my head when my head hits the pillow at night.

Biofuels can fix that little issue. The United States is a vast country with a whole heck of a lot of land that can be used for growing stuff… not necessarily corn, but something. Switchgrass is suitable for growing in climates where it’s too dry for corn. Kudzu grows all over the south whether they want it to or not, and algae is a nuisance in lakes and coastal waters all over the country. All of these are being looked at as excellent candidates for ethanol conversion.

Plus, not shipping oil thousands of oils in massive tankers would mean no oil spills, and don’t kid yourself, they happen all the time… just not in America. That’s certainly a more environmentally friendly thing to do.

Disadvantages of biofuels

Americans like to drive – there’s no doubt about that. However, we also like to eat. And while there are several non food plants being looked at for ethanol the main way to make ethanol in this country is to use corn. If it’s not used as food for people, it’s used as food for cows or other livestock which then become food for people. Using corn for ethanol has caused corn prices to rise dramatically which leads to an increase in food prices since nearly everything on the store shelves has corn as an ingredient. (Just look at how many things have corn syrup in them.)

Then there’s the little nagging issue about converting corn into ethanol not being efficient. Right now optimistic estimates are that you get 1.25 unit of energy back for every 1 unit you put in. Less optimistic ones say it’s actually energy negative meaning it takes more energy (diesel fuel used to run tractors that plant and harvest the corn and trucks used to transport it) to produce ethanol than you get in return. Obviously, scientists and engineers are trying to make the process far more efficient and think they can get up to a 7 to 1 return on energy units, but right now they’re nowhere close.

And while biofuels are certainly greener than their fossil fuel brethren, they’re not exactly zero emission fuels. You certainly don’t want to breathe that stuff coming out of your tailpipe even if it does smell like french fries.

Infrastructure

In terms of infrastructure, very little would need to change at your local gas station. A gas pump is a gas pump whether or not it’s pumping gas, diesel, biodiesel, ethanol, or refried beans (now that stuff’ll give ya gas).

We’d either need to build new refineries which is already in progress for ethanol plants across the Midwest or we’d need to retrofit the old ones designed to make gasoline. Either way it’s a fairly expensive process, but it wouldn’t require much adaptation on the consumer’s part since your engine would sound, smell, and drive the same as it always has.