Mean Green

As the new millennium begins, people have never been so eco-conscious. In recent years, the imminent threat of global warming has compelled us to re-consider how we do and make things. This is most especially true when it comes to our daily means of transport — the car — which unfortunately, ranks among the major contributors of air pollution (and noise pollution) in the world. Thankfully, scientists are continuing to explore new ways to address this. One of these is the use of alternative fuel vehicles (AFV).

An AFV is any vehicle that doesn’t run on petrol or diesel fuel, although a car can be considered an AFV if it doesn’t rely exclusively on petroleum to function (like hybrid cars, which rely on petrol fuel and electricity). What are the different kinds of AFV? Let’s find out.

Hybrids. Hybrids use both gasoline and electricity to run. These vehicles normally feature an internal combustion engine and a battery pack which combine to give the vehicle its propulsion power. Hybrid cars have gained popularity over the years — the most common examples are the Toyota Prius and the Honda Insight.

Battery Electric Vehicles. As its name applies, a BEV depends on the power of its battery pack. BEVs are among the cleanest vehicles because they don’t produce any carbon emission at all. Battery types may include nickel cadmium, lithium-ion, zinc-air or lead-acid batteries.

Biofuel Cars. Bioalcohol (or Ethanol) and Biodiesel are two types of biofuels that can be used on automobiles. There are still biofuel cars available today but most prefer the flexible-fuel vehicle.

Flexible-fuel Vehicles. With FFVs, you can use more than one type of alternative fuel. This is possible through the use of a multifuel engine which allows you to mix certain alternative fuels in the tank and is combusted as one. These cars are mostly found in the US and South America.

“Gas”-Powered Cars. Certain types of AFVs also run using compressed natural gas, biogas, liquid petroleum gas (or autogas), nitrogen gas, propane and hydrogen. Usually, these cars are your standard petroleum-using vehicles whose engines are modified to burn the alternative gaseous fuels.

The Solar Car. Solar cars use solar panels in order to harness the power of the sun. This type of AFV has been around for decades but unfortunately, no practical prototype has been developed yet for the masses. Nevertheless, countless solar car contests and races are being held every year and participated in by schools and universities all over the world.

AFVs may be environment-friendly but it has its disadvantages, too. AFVs are still a bit more expensive than the usual cars in the market and the availability of alternative fuels is still very limited. But still, the future promises more developments, new possibilities. Who knows? The first commercially-successful AFV may just be around the corner.

With the various tax incentives on offer, and increasing concern about both pollution and future fuel prices, it is not hard to see why HybridVehicles are becoming more popular.

Most of us know by now that a Hybrid Vehicle has two sources of power;an electric motor and the good ol’ Internal Combustion Engine (ICE).However, most people don’t know much beyond that so let’s go deeper:let’s cut through the jargon and have a look at how Hybrid Vehiclesactually work.

Hybrid vehicles are usually based on two main designs; a paralleldesign, or a series design.

With a parallel design, the electric motor and ICE are both connecteddirectly to the vehicle’s wheels. The ICE is used for normal driving;the electric motor provides additional power during acceleration, hillclimbs and other occasions of high demand.

With a series design, the ICE is connected to a generator which is usedto charge the batteries. It is the batteries which actually power thewheels via the electric motor.

Some hybrid vehicles use the series design at low speeds, and theparallel design for highway driving and acceleration.

Regenerative braking: normally the deceleration of a vehicle is wastedenergy; not so with Hybrids. Hybrids can use regenerative braking tocapture and store the energy lost in slowing down the vehicle aselectricity. The electricity can later be used to propel the vehicle.This increases the overall efficiency of the vehicle as energy that wasotherwise wasted is being stored and used again later.

Also energy that would otherwise be wasted while idling or cruising canalso be stored for later use. While cruising the ICE uses a lot of fuelin proportion to the actual work going into driving the wheels. Thismakes it particularly inefficient at those times. To increase efficiencysome of the output from the ICE is fed to a generator to charge thebatteries when the vehicle is cruising or travelling downhill.

Another clever trick is that the electric motor normally used to drivethe wheels can be used as the generator. This is how the regenerativebraking process, and the system for charging the battery during engineidling, generate electricity. At those times the electric motor is notneeded for propulsion, therefore, the ability of an electric motor tooperate in ‘generator’ mode is utilised so that a separate generator isnot required.

Vehicles which use the parallel or series design are sometimes known asFull Hybrids. Other types of Hybrids such as the Assist Hybrid and MildHybrid are basically just normal vehicles with a bit of electrical powersupplied at crucial moments. They may also offer Regenerative Braking.However, this kind of vehicle only provides about a 10% increase in fueleconomy and it is open to question as to whether the extra complexity isworthwhile.

Is the future of hybrid diesel?

The future of hybrids may very well lie in the diesel motor. Dieselengines operate at higher efficiency than petrol engines so deliver moremiles to the gallon, plus they are more reliable. Their maindisadvantage has always been poor acceleration, but in a hybrid this isnot an issue as it can be offset with extra propulsion from the electricmotor.

In addition, diesel engines can run on biofuels such as vegetable oiland the like. Such fuels are relatively clean and are not the dirtystuff often associated with diesel propulsion. Biofuels can be obtainedin a sustainable way and the costs are relatively independent of oilproduction and oil prices.

The combination of reliability, fuel economy (prototypes have achievedover 110 mpg US fuel economy) and sustainable sources of fuel, makes thediesel-engine based hybrids not only likely, but inevitable. This willhopefully give us breathing space till fuel cell technology matures.

Should you Buy a Hybrid Vehicle?

Here are some resources to help you decide:

You can check out this comparison charthttp://go.ucsusa.org/hybridcenter/compare_chart.cfm which will helpyou compare some hybrids with non-hybrids and a reference list of allFederal and State incentives for prospective hybrid ownershttp://go.ucsusa.org/hybridcenter/incentives.cfm .

Some topical articles; Buyers of hybrid cars get a pleasant surprisehttp://www.rocklintoday.com/news/templates/automotive_news.asp?articleid=3110&zoneid=1and one persons experience of the Cost of Owning a Hybrid carhttp://www.hybridcars.com/blogs/sans-suv/apples-oranges.

Consumer Reports have now admitted that they made an error when theysaid owners of hybrid vehicles would pay more than buyers of comparablegasoline-only vehicles over their lifetime of ownership. Owners of theToyota Prius and Honda Civic hybridshttp://www.hybridcars.com/news/news.php?news_id=832 do save money, themagazine now says.

If you want more in-depth technical information try What is a HybridElectric Vehicle?http://www.eere.energy.gov/cleancities/hev/what_is_hev.html/ whichincludes a nice simple overview of hybrid vehicle designhttp://www.eere.energy.gov/cleancities/hev/hev_components.html and thepage Hybrid Electric Vehicleshttp://www.nrel.gov/vehiclesandfuels/hev/hevs.html has clear technicalexplanations.

Wikipedia has a well written Hybrid vehiclehttp://en.wikipedia.org/wiki/Hybrid_car entry which includes bothtechnical and ecological issues.

If all that is not enough for you try the Hybrid Electric Vehicle bloghttp://hybridblog.typepad.com which has lots of good info and links.