To begin with, there are already some 13 million CNG (compressed) and LNG (liquid) natural gas powered cars on world roads today. Many of these cars are fleet vehicles and DIY vehicles that work well in their niche. Most CNG cars are found in the countries listed on the chart to the right. The top 5 countries on the list have 77% of the NGVs.
Pakistan is the world leader in natural gas powered cars. Major car manufacturers offer a variety of CNG models for sale in the country. In addition, many NGVs are conversions. These cars do lack western safety standards. By comparison, the only factory built CNG car for sale in the United States (at this time) is the Honda Civic CNG. Conversion kits are available in the US, but installation at present is very expensive due to regulations.
Approximate number of CNG Cars and fueling stations by country - March 2012. **India likely hosts millions of unregistered NGVs.
Interpret the Numbers
Nearly all of the Pakistaini NGVs are really flex fuel vehicles that can also burn gasoline or diesel. Some 90% of the 4.2 million natural gas powered cars in the Latin Americas are the same bi-fuel powered vehicles. This is true in other countries. So, many NGVs are really flex fuel vehicles, and many of those are gas/diesel conversions.
Many NGVs are fleet vehicles like city busses and trucks. These vehicles are typically fueled at larger centralized service centers where they are assured a reliable supply of the cheap fuel. These vehicles do make sense in congested urban centers where diesel tailpipe pollutants are a major health hazard.
Natural Gas Vehicle Advantages
Advantages of natural gas powered cars are a cheap and relatively clean fuel. Natural gas supplies appear to be greater than oil supplies at the moment, though not even in the same ballpark as renewable energy. Long life: NGVs burn much cleaner and reduce wear and tear on the internal combustion engine considerably. 500,000 miles on an engine is entirely possible.
Natural Gas Vehicle Disadvantages
The two main disadvantages of natural gas are the same as for crude oil. Gas pollutes when burned, and as a fossil fuel it is limited in supply. There is a gas bubble at the moment, but there was a real estate bubble a few years back too.
Natural gas stations are in many places few and far between, though there are home installations for CNG users.
Natural gas is typically stored at very high pressures which requires specialized tanks and other devices for fueling and storage. Tanks for retrofitted cars are typically placed in the trunk of the car which reduces storage space.
Natural Gas Charge Stations
New NG filling stations are being installed daily. As with EV charge stations, there are sites dedicated to tracking
locations of NG stations.
The main factor driving the current NGV boom in developed countries is cheap gas. It pays to remember that what goes down can also come back up. Natural gas is a limited fossil fuel just like crude oil. There just happens to be
an excess now. The world supply is around 300 trillion cubic meters and world use is around 3.3 trillion cubic
meters per year. This gives a 91 year supply. This number will change, but gives an idea of supply and demand.
Lets take a look at supply and demand in the USA. According to the US IEA, there are some 2,543 trillion cubic
feet (Tcf) of potential NG supply as of 2011. Annual NG use in the U.S. Is about 24.1 Tcf per year. At present use rates then there is a 106 year supply. Sounds like some cushion.
However if you add in transport, gas in the bank drops dramatically. Motorists in the USA use a Lot of gas. If all gasoline and diesel were replaced by natural gas, the amount drops to a 44 year supply. This is just an estimate
and supply and demand will change over time, but it gives you an idea of the limitations of fossil fuels in the future.
Bottom line: when you add the burden of transport onto NG, future supplies drop by around half.
World and USA Natural Gas supply and demand at current use rates
NG conversions place the storage tank in the truck reducing storage space.
Types of Natural Gas used for Natural Gas Powered Cars
Natural gas comes in three basic types: CNG or compressed natural gas, LNG or Liquid Natural Gas, and LPG or Liquid Petroleum Gas. CNG is natural gas that is compressed to a high pressure for storage in a tank. It is the same gas you use in your home for heating and cooking.
LNG is natural gas compressed to 1/600 of its original volume into a liquid for transport. LNG is produced like any natural gas, then it is compressed, transported, vaporized and piped to its destination. The vaporized gas is higher in BTU content and may cause problems when burned in standard appliances.
LPG, or liquified petroleum gas, is a compressed, liquid mixture of gasses, mostly propane and butane. LNG is heavier than air and tends to pool beneath a vehicle during leaks, allowing possible ignition. It takes about 20 minutes to re-fuel a light duty vehicle with LPG. Finally, LPG tanks are not as robust as CNG tanks, and are more at risk of rupture in an accident.
Natural Gas Impacts
Natural gas is a fossil fuel. However, it does burn cleaner than other fossil fuels. NG burned in light cars and trucks produces about 90 percent less NOx and 98 percent less hydrocarbons than gasoline cars.
Greenhouse gas emissions are lowered, but not as much as expected. NG vehicles produce about 20 percent less greenhouse gas than gas powered cars, and diesel powered trucks.
So, NGVs can be used to combat air pollution.
Natural Gas Conversions and Safety
Millions have converted their oil burners to natural gas powered cars. This has worked for many, though there are some serious safety considerations to keep in mind. Others have learned the hard way.
In terms of safety, if a NGV vehicle is converted or built to safety standards, it will be relatively safe. Tanks are generally thick walled enough to withstand the impact of collision. However, if gas is allowed to leak at the seals, you can develop a problem. We recommend a licensed installation.
In the US of A, installation by a licensed professional will set you back from around $6,000 to $15,000 USD. In other countries the installation might as low as a few thousand dollars USD. The parts only cost a few hundred bucks besides perhaps the NG tank, the most expensive part. How come so much to install? Again, safety standards. Don't go too cheap.
You can also get a home re-fuel device, the FuelMaker 'Q' refueling appliance or Phill. The Phill nozzle will set you back around $4,500 plus installation cost USA.
Price varies a lot with location
LPG - a mix of propane and other natural gasses. Food giant Schwan's runs 90% of its trucks on propane.
Natural gas accounts for about one quarter (25%) of total energy use. Use is on the rise. Natural gas
powered cars are part of the reason for the increase.
The USA uses the most NG, followed by The Russian Federation, China and Iran.
NG is cleaner than oil or coal, but it still produces greenhouse gasses.
While NG does work well for transport, it is not likely to replace oil burners anytime soon. The US IEA forecasts that
by 2035 around 3% of transport will be NG powered. This lags behind EVs.
A lot of NG gets wasted....flared. Some 150 billion cubic meters, almost one billion barrels of oil equivalent simply go up in smoke at the site.
Shale gas and other NG from fracking appears a panacea of supply. However, it is possible that these supplies may be overestimated as production drops over time. Since the technology is new, only time will tell.
CNG storage for natural gas powered cars at the present is by high pressure. Many molecules are forced into a small space under pressure. The pressure is a problem if there is a tank rupture - think explosion.
Researchers at the Univ. Of CA. Berkely are looking into absorption to reduce the pressure. The idea is to put microporous materials inside the tank that will efficiently soak up gas molecules. You get the same amount of storage at lower pressures. The work is in the simulation stage. Researchers have simulated how parallel layers of carbon atoms can adsorb methane atoms. Stay tuned.
Finally, natural gas powered cars make a lot of sense in certain situations. However, in our view they are no better suited or likely than EVs to take over transport any time soon.
Natural Gas Costs and Savings
At the time of writing, CNG was selling from less than 1/4 to over 1/2 the cost of regular unleaded gasoline. The price varies a lot with location. Texas for instance has a lot of natural gas and lower prices. Californians and New Yorkers will pay a lot more. So, how long to recover your investment?
You need to know how much the cost difference is between the gasoline and natural gas powered cars you are interested in, and the cost difference between gasoline and natural gas in your area. Then you can follow the example below to estimate your miles to break even.
Honda Civic Natural Gas Powered Cars.
At $27,000 it takes awhile to break even
Natural Gas Cars and Trucks
Natural gas powered cars are not exactly "EVs" but in some cases present a practical transport alternative to electric vehicles. We do not think that natural gas vehicles (NGV) are the next best thing to take over electric vehicles however.
According to the US IEA, natural gas is the world's fastest-growing fossil fuel, with consumption increasing at an average rate of 1.6 percent per year from 2008 to 2035.
Prices however are projected to rise from $11.32 per tcf in 2013 and $12.02 in 2014.
One gallon of gasoline equals about 127 cubic feet of Compressed Natural Gas (CNG). This brings the price of CNG to about $1.44 per gallon in 2013.
Recent articles suggest that natural gas powered cars could and should replace electric cars due to the excess of cheap, clean burning fuel. Lets look at why.
November 2012: Chrysler begins production of Ram 2500 CNG Bi-Fuel trucks for its fleet customers.