8. Alternative Fuel Vehicle Safety

Compressed Natural Gas (CNG) as a Safe Vehicle Fuel

CNG used as a transportation fuel has an excellent safety record. One reason is that CNG has a higher ignition temperature than either gasoline or diesel, making accidental ignition less likely than with conventional liquid fuels. Natural gas also has a tight flammability range meaning that when concentrated in air below about 5 percent or above roughly 15 percent, natural gas will not burn. Another safety attribute of CNG is that it is lighter than air, dissipating quickly into the ambient air if accidentally released. Of course, this feature may cause concern indoors, and special detection and ventilation systems are used to address this issue.

NGV fuel tank cylinders used for onboard CNG storage are much stronger than gasoline tanks. They are designed to withstand thousands of pounds of internal and external pressure and have been subjected to rigorous government testing including severe physical impact (i.e., gunfire, collisions and fires) and extreme pressure and temperature tests.

Electricity as a Safe Vehicle Fuel

Electric motors have been around for more than 150 years and are a proven technology. When the automobile was first introduced at the turn of the 20th century, it was powered by batteries. Today, we couldn't imagine daily living without all our electrically powered appliances. Furthermore, the modern electricity transmission and distribution systems are remarkably reliable. Today's EVs incorporate space age materials that combine light weight with great strength. Even batteries have become far safer as older batteries have been replaced with new technologies that replace liquid chemicals with gels or absorbent materials. In fact, in the long run, vehicles powered by electricity and natural gas may prove to be safer than the cars we have been driving for 75 years! Automobile manufacturers have built in many safety features such as a switch that automatically cuts power to the vehicle motor in an accident and protective frames around the battery packs.