Well we are always on the look out for new energy technologies to tell you about. Today we want you to check out this car that is powered by compressed air. Yes that is right compressed air! Watch the videos (one from CNN) and then give us your thoughts below on whether you think something like this could catch on and be a viable alternative energy source for cars.
The advantages for this air powered car technology that we see include…
* Low cost for the car and to run it
* About 117 MPG
* Low Emissions (or zero emissions)
* No need for batteries – that’s the biggest problem with electric vehicles
More comprehensive from Wiki:
Advantages
The principal advantages of an air powered vehicle are:
* Refueling can be done at home using an air compressor[3] or at service stations. The energy required for compressing air is produced at large centralized plants, making it less costly and more effective to manage carbon emissions than from individual vehicles.
* Compressed air engines reduce the cost of vehicle production, because there is no need to build a cooling system, spark plugs, starter motor, or mufflers.[4]
* The rate of self-discharge is very low opposed to batteries that deplete their charge slowly over time. Therefore, the vehicle may be left unused for longer periods of time than electric cars.
* Expansion of the compressed air lowers its temperature; this may be exploited for use as air conditioning.
* Reduction or elimination of hazardous chemicals such as gasoline or battery acids/metals
* Some mechanical configurations may allow energy recovery during braking by compressing and storing air.
* Recent findings from Southwest Research Institute indicate that air-hybrids would allow for up to 50 percent better fuel economy and an 80 percent reduction in emitted toxins compared to conventional engines[citation needed]. Sweden’s Lund University also reports that buses could see an improvement in fuel efficiency of up to 60 percent using an air-hybrid system[5]
Disadvantages
The principal disadvantage is the indirect use of energy. Energy is used to compress air, which – in turn – provides the energy to run the motor. Any conversion of energy between forms results in loss. For conventional combustion motor cars, the energy is lost when chemical energy in fossil fuels is converted to heat energy, most of which goes to waste. For compressed-air cars, energy is lost when chemical energy is converted to electrical energy, and then when electrical energy is converted to compressed air.
* When air expands in the engine it cools dramatically (Charles’s law) and must be heated to ambient temperature using a heat exchanger. The heating is necessary in order to obtain a significant fraction of the theoretical energy output. The heat exchanger can be problematic: while it performs a similar task to an intercooler for an internal combustion engine, the temperature difference between the incoming air and the working gas is smaller. In heating the stored air, the device gets very cold and may ice up in cool, moist climates.
* Conversely, when air is compressed to fill the tank it heats up: as the stored air cools, its pressure decreases and available energy decreases. It is difficult to cool the tank efficiently while charging and thus it would either take a long time to fill the tank, or less energy is stored.
* Refueling the compressed air container using a home or low-end conventional air compressor may take as long as 4 hours, though specialized equipment at service stations may fill the tanks in only 3 minutes.[3] To store 14.3 kWh @300 bar in 300 l (90 m3 @ 1 bar) reservoirs, you need at least 93 kWh on the compressor side (with an optimum single stage compressor working on the ideal adiabatic limit), or approx. 65kWh with an industrial standard multistage unit. That means, a compressor power of over 1 Megawatt (1000 kW) is needed to fill the reservoirs in 5 minutes from a single stage unit, or several hundred horsepower for a multistage one.[6][citation needed]
* The overall efficiency of a vehicle using compressed air energy storage, using the above refueling figures, cannot exceed 14%, even with a 100% efficient engine—and practical engines are closer to 10-20%.[7] For comparison, well to wheel efficiency using a modern internal-combustion drivetrain is about 20%,[8] Therefore, if powered by air compressed using a compressor driven by an engine using fossil fuels technology, a compressed air car would have a larger carbon footprint than a car powered directly by an engine using fossil fuels technology.
* Early tests have demonstrated the limited storage capacity of the tanks; the only published test of a vehicle running on compressed air alone was limited to a range of 7.22 km.[9]
* A 2005 study demonstrated that cars running on lithium-ion batteries out-perform both compressed air and fuel cell vehicles more than threefold at the same speeds.[10] MDI has recently claimed that an air car will be able to travel 140 km in urban driving, and have a range of 80 km with a top speed of 110 km/h (68 mph) on highways,[11] when operating on compressed air alone, but in as late as mid 2009, MDI has still not produced any proof to that effect.
* A 2009 University of Berkeley Research Letter found that “Even under highly optimistic assumptions the compressed-air car is significantly less efficient than a battery electric vehicle and produces more greenhouse gas emissions than a conventional gas-powered car with a coal intensive power mix.” however they also suggested, “a pneumatic–combustion hybrid is technologically feasible, inexpensive and could eventually compete with hybrid electric vehicles.”[12]
