Document ID: EPA-HQ-OAR-2014-0827-0107
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2015-07-13T04:00Z

FPinnovations
FAQ  -  Frequently Asked Questions
Will the price of natural gas increase?
Although predicting the future is a tenuous proposition at best, the likelihood is that NG prices will rise. However this is not expected to occur within the lifetime of the first trucks adopting natural gas, as demand is low for natural gas and supply is high. Conditions for rising gas prices will not occur rapidly.

Will natural gas trucks decrease in price?
Significant price reductions are unlikely in the next five years, but perhaps within the next decade prices will decrease as more trucks are built and the cost of storage vessels become less due to improvements in manufacturing technology.

What is CNG?
Compressed natural gas, or methane, is compressed to 200bar or 2,900psi and has an energy density 9.3 MJ/L or 300 times that of natural gas at atmospheric pressure. 

What is LNG?
Liquefied natural gas is super-cooled to -162°C and has an energy density 22.4 MJ/L or 600 times that of natural gas at atmospheric pressure. 

Can my natural gas truck use both LNG and CNG?
No. The storage vessels are radically different. CNG storage vessels are typically made of high pressure capacity carbon fibre construction, whereas LNG storage vessels are resistant to extreme cold, and have dual wall construction with a vacuum sealed chamber between the tanks' inner and outer layers  -  much like a thermos used for hot beverages.

Will LNG trucks meet my heavy trucking needs?
Currently OEM offerings are limited to 475hp (354kW) and 1,750 lb-ft (2,373Nm) torque. This should be adequate for most fleets' needs, with higher horsepower capable engines coming in the future. Fumigation systems of higher capacity are also offered by the aftermarket retrofit industry, but typically these are used in off-road industrial engines.

Will CNG trucks meet my light trucking needs?
Currently OEM offerings are limited to 400hp (298kW) and 1,450 lb-ft (1,898Nm) torque. This engine is best suited for trucks with a GVW of less than 80,000lbs (36,280 kg).

Should I wait to purchase an NG truck?
Incentives will not likely be repeated in the future and prices for equipment should not decrease in the foreseeable future. Early adopters will gain a competitive advantage in the market place, but smaller fleets will need to wait until infrastructure if built to service their needs.

Are natural gas trucks safe?
Natural gas trucks have proven to be safe in other parts of the world and employ several safety features. The fuel itself has many characteristics similar to other conventional motor fuels, with some distinct advantages, such as being lighter than air and non-toxic to water sources.

Do natural gas trucks weigh more than conventional diesel trucks?
Yes. Some trucks are marginally heavier, but other can be significantly heavier, be sure to check tare weight and how this affects the trucks payload. Some provinces, such as British Columbia have a 1,500kg weight allowance for natural gas trucks.

Can I run my natural gas truck on diesel?
This depends upon the technology used. Fumigation systems augment the fuel delivery system of a conventional gasoline or diesel engine; therefore these systems can revert to a diesel or gasoline fuel only mode of operation. CNG systems like the Cummins Westport system run solely on natural gas, whereas the Westport Innovations LNG HD475 engine can run diesel only, but with dramatically reduced power.

What happens if my truck runs out of natural gas?
As stated in the previous question, it will depend on the technology. A Westport CNG truck will need a tow truck if run out of fuel, whereas their LNG Westport HD475 engine can run on diesel only with dramatically reduced power. If such an engine were to run out of fuel while the truck was loaded, fuel would either need to be delivered to the truck (an unlikely scenario), the truck towed, or the load transferred to another truck and the truck then travel at reduced speed with no load.

What safety systems are employed on a natural gas truck?
Failsafe valves close in the event of lost power. Fuel vessels are durable with multiple layers and methane detectors are positioned under the hood and in the driver's compartment.

What safety systems are employed at a LNG or CNG fuelling station?
Failsafe valves close in the absence of electrical power and pumps automatically shut off if an alarm is triggered. In addition, LNG tanks are placed in containment berms of 110% capacity. Pumps and tanks are protected from traffic impact.

Do I need specialized training to operate a natural gas truck?
Yes. The truck's safe operation is covered by the OEM's documentation, but currently not covered by specific provincial licensing requirements.

Do I need specialized training to fuel a natural gas truck?
Yes. In addition to proper personal protective equipment, fill station attendants and drivers who fill these trucks must be trained. This training can easily be accomplished in one day.

Is a natural gas truck more expensive to maintain?
Although there is very little data on maintenance cost the preliminary experience is that the maintenance cost is higher. Expect to pay approximately $0.01 more per kilometre in additional maintenance costs, with extended warranties to cover costly components being highly recommended.