Alternative fuel vehicles

Alternative Fuel Vehicle refers to a vehicle that runs on a fuel other than traditional gasoline or diesel; any method of powering an engine that does not involve solely petroleum (e.g. electric car, gasoline-electric hybrid, solar powered, auto LPG, CNG etc.).

Current research and development is largely centered on "hybrid" vehicles that use both electric power and internal combustion. The first hybrid vehicle available for sale in the United States was the Honda Insight, achieving around 70 miles per gallon (25.5km per liter).

Other research and development efforts in alternative forms of power focus on developing fuel cells, alternative forms of combustion such as Gasoline Direct Injection (GDI ) and Homogeneous Charge Compression Ignition (HCCI), and even the stored energy of compressed air.

Air car
The air engine is an emission-free piston engine that uses compressed air as a source of energy. The first compressed air car was invented by a French engineer named Guy Nègre.

The expansion of compressed air may be used to drive the pistons in a modified piston engine. Efficiency of operation is gained through the use of environmental heat at normal temperature to warm the otherwise cold expanded air from the storage tank. This non-adiabatic expansion has the potential to greatly increase the efficiency of the machine. The only exhaust is cold air (-15 °C), which could also be used to air condition the car. The source for air is a pressurized carbon-fiber tank holding air at 3,000 lbf/in² (20 MPa). Air is delivered to the engine via a rather conventional injection system. Unique crank design within the engine increases the time during which the air charge is warmed from ambient sources and a two stage process allows improved heat transfer rates.

This engine was used to power an urban car with room for five passengers and a projected range of about 100 to 200 miles (160 to 320 km), depending on traffic conditions. The main advantages are: no roadside emissions, low cost technology, engine uses food oil for lubrication (just about 1 liter, changes only every 30,000 miles (50,000 km) and integrated air conditioning. Range could be quickly tripled, since there are already carbon fiber tanks which have passed safety standards holding gas at 10,000 lbf/in² (70 MPa).

The tanks may be refilled in about three minutes at a service station, or in a few hours at home plugging the car into the electric grid via an on-board compressor. The cost of refilling is projected to be about US$3.

Battery-electric
General Motors EV1, battery-electric vehicleBattery Electric Vehicles (BEVs) are electric vehicles whose main energy storage is in the chemical energy of batteries. BEVs are the most common form of what is defined by the California Air Resources Board (CARB) as zero emission (ZEV) passenger automobiles, because they produce no emissions while being driven. The electrical energy carried onboard a BEV to power the motors is obtained from a variety of battery chemistries arranged into battery packs. For additional range genset trailers or pusher trailers are sometimes used, forming a type of hybrid vehicle. Batteries used in electric vehicles include "flooded" lead-acid, absorbed glass mat, NiCd, nickel metal hydride, Li-ion, Li-poly and zinc-air batteries.

The Henney Kilowatt, the first modern (transistor-controlled) electric car.Attempts at building viable, modern battery-powered electric vehicle began in the 1950s with the introduction of the first modern (transistor controlled) electric car - the Henney Kilowatt. Despite the poor sales of the early battery-powered vehicles, development of various battery-powered vehicles continued through the 1960(notably General Motors with the EV1), but cost, speed and inadequate driving range continued to make them impractical. Battery powered cars have primarily used lead-acid batteries and NiMH batteries. Lead-acid batteries' recharge capacity is considerably reduced if they're discharged beyond 75% on a regular basis, making them a less-than-ideal solution. NiMH batteries are a better choice, but are considerably more expensive than lead-acid. Lithium-ion battery powered vehicles such as the Venturi Fetish have recently demonstrated excellent performance and range, but they remain very expensive.