The Case Against Metro's LRT PLan

Boone Pickens has recently been calling attention to the potential of natural gas (NG) as an alternative fuel for vehicles. There are two basic alternatives, compressed natural gas (CNG) and liquefied natural gas (LNG). Using NG to fuel vehicles is not new. Europe has been using NG vehicles for, at least, 50 years. Worldwide it is estimated that there are approximately 7 million NG vehicles. There are approximately one million in the U.S.

There are some distinct advantages to the use of CNG as a fuel instead of gasoline or diesel. The principal advantage is that CNG is much cleaner fuel. CNG engines produce less fine particulate matter (PM), smog producing NOX and VOC and CO₂ than either gasoline or diesel engines. The amount of emissions reduced varies based on the size and type of engine. But generally, the largest reductions come from replacing large diesel engines. For example, according to Cummins Westport their newest NG heavy-duty engine, primarily used for refuse and bus applications, emits 6X less NOx than the newest clean diesel applications. For some specific test comparison results click here. Additionally, CNG does not have to be refined or transported by truck and thus eliminates those associated emissions. For a non-attainment region ^[1], like Houston, NG vehicles could make a substantial contribution in the reduction of emissions.

Also, at today’s prices, there is a significant savings from CNG. CNG prices vary substantially, but generally the price per gallon equivalent (PGE) is just under $3. Some fleet operators with long-term NG supply contracts report even lower costs.

Finally, the U.S. has a very large supply of natural gas. The Energy Information Agency (EIA) projects that domestic production of natural gas will be near 20 trillon cubic annually through 2030.^[2] A significant conversion of vehicle fuel from imported oil to domestic natural gas could be a meaningful part of our energy independence. Also NG, which is primarily composed of methane (CH₄), is a renewable source that can be generated from landfills and wastewater treatment plants.

However, there are also some significant disadvantages to NG vehicles. First, NG vehicles are significantly more expensive. The only original equipment manufactured (OEM) vehicles are a Honda GX and heavy duty trucks. The only current alternative for light duty trucks or sedans is after-market conversions. These after-market conversions for light/medium-duty vehicles can run $10,000-$15,000. Heavy-duty OEM NG trucks will typically cost an extra $40,000 to $60,000. However, there are various government grants and tax credits that assist in the purchase of NG vehicles.

Also, the space required to store CNG is significantly greater than gasoline. As a result vehicles typically must give up some of their storage capacity to accommodate the larger tanks. As shown in the photograph below, the CNG tank takes up about 1/3 of a half-ton pick-up bed. On a refuse truck, the CNG tanks add about two feet to the chassis length.

NG tank in bed of pick-up NG tank on garbage truck

Another disadvantage is that light-duty NG vehicles have a considerably shorter range than gasoline or diesel vehicles. Generally, around 200 miles is the maximum range. This limited range is combined with the fact that there are only a handful of locations where NG is publicly available makes NG vehicles fairly impractical for personal use.

The place where NG vehicles make the most sense is in large fleet operations which return to the same location each day. Garbage trucks for example are an excellent application. San Antonio and Austin both fuel a portion of their garbage trucks with NG. Also, many transit agencies are using NG vehicles. DART, Dallas’ transit agency, now operates nearly 200 NG buses and the City Dallas has 1,200 NG vehicles. Airport shuttles are another common application.

Surprisingly, little has been done in the Houston region to develop NG vehicle applications. Neither Metro nor the City of Houston has any NG vehicles. Metro conducted a test of LNG buses in the 1990s. The tests were not successful and apparently left a bad taste in Metro’s mouth for NG buses. However, at a recent Metro Board meeting, Board member George DeMontrond requested that the staff take another look at NG as an alternative.

The City of Lake Jackson began a CNG program in 2000 and now operates 16 garbage trucks, about a dozen light duty trucks and six Honda NG sedans which are used by the public works department. Lake Jackson has a long-term supply contract giving it a current cost of $1.38 PGE! Lake Jackson has its own compressor station at its fleet barn where the vehicles are re-fueled overnight. Craig Nesbitt, the public works director there gave me a tour of their facilities. For anyone interested, he is very knowledgeable and generous with his time in sharing Lake Jackson’s experience.

NG refueling station Lake Jackson compressor station

There are a number of private companies in the region testing NG applications. Silver Eagle and HEB have converted several of their large delivery trucks.

NG vehicles are not a silver bullet solution to our energy or air quality problems. However, it does appear to be a piece of the puzzle. At a minimum we should be testing applications in our garbage trucks, transit buses and airport shuttles. Houston is after all the natural gas capitol of the world. It hardly seems right that Dallas, San Antonio and Austin would be ahead of us!!!

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[1] A non-attainment region is one that does not meet Federal ozone standards.

[2] http://www.eia.doe.gov/oiaf/aeo/pdf/trend_4.pdf

A few weeks ago, I headed to my family's bay house in Kemah for the weekend and needed to stop for gas before making the trip. After leaving over $80 with the station, I thought I would drive to Kemah at the posted speed limit and see how much it improved my gas mileage. I was stunned. I drive a full-size sedan that averages about 20mpg. On the trip to Kemah, I got 32mpg. On the trip down I was reminded of a recent story in the Chronicle where two reporters had driven all major freeways around Houston at the posted speed limits. Predictably, they were passed thousands of time. Click here to read the Chronicle article. I had the same experience, as many SUVs and large trucks roared past me at well over 80mph. I wondered if they had any idea what their gas mileage was that those speeds.

After our trip, my wife, Melissa and I decided that we would consciously begin driving in a manner that would improve our gas mileage. At the same time, we looked for opportunities to consolidate trips. Since we have started, our weekly expense has actually gone down. We have cut our gasoline usage by about 20%.

Our experience is confirmed by a number of websites and organizations promoting greater driving efficiency. A good summary can be found at the Department of Energy's site: click here to go to the summary. There are a number of websites that provide suggestions to improve gas mileage efficiency, but all clearly emphasize that the most important factor in your car's gas mileage is the speed at which you drive. The basic science behind this is that wind drag on your car increases exponentially with an increase in vehicle speed. So, if you double your speed, the drag is cubed, or 8X greater. This was the theory behind the 55mph speed limit back in the 1970s. To some extent, the inefficiency caused by wind drag is overcome by your car shifting to higher gears. The optimum speed for the best gas mileage is different for each car. But generally, the sweet spot will be somewhere in the 55-65 mph range.

There is a very steep penalty for exceeding this range. The Department of Energy estimates that driving 75mph instead of 55mph, will decrease your gas mileage by about 20%. That is the equivalent of increasing the price of gas by about 80¢ per gallon. In other words, if you would like to lower your gas price from $4.00 per gallon to $3.20 per gallon, slow down to 55-60 mph.

There is another benefit from driving slower. It is safer. Amazingly, we still lose about 40,000 lives each year in traffic accidents in this country, more than 10X all the Iraq War causalities. There are about 500 traffic related deaths annually in Harris County alone. The Houston Galveston Area Council (HGAC) has estimated that about a third of the accidents in our area are caused by excessive speed.

There are also environmental benefits to burning less gasoline. Each gallon of gasoline produces 19.5 pounds of CO2 along with smog producing nitrous oxides and volatile organic compounds.¹ If we cut the number of gallons burned each year by 10-20%, it would make a marked difference in our air quality.

But increasingly, I am beginning to feel that conserving gasoline is a patriotic act. Our economy today is in a wreck largely because of our addiction-like reliance on foreign oil. We are paying billions of dollars to other countries for oil that we are literally burning up in smoke. In the meantime, they are recycling those dollars, buying up American real estate and companies. We are being taken over by other countries not by military might, but by our own inability to curb even slightly, our ravenous appetite for gasoline.

The ironic thing is that our reduction in gasoline usage has had virtually no impact on our lives. I do not miss any trips that we have not made. And by driving the speed limit and listening to music or books on tape while I am driving, I arrive more relaxed and rested than when I was pretending to be a race car driver.

Every day, Americans use a little over 9.3 million barrels of gasoline. We have actually begun to reduce our usage already. For the week of June 20, we cut about 200,000 barrels a day from the same week last year. But this is a measly 2%. Just by slowing down and driving more carefully, we could easily save five times that amount.

Today, we are importing about twice the crude oil we were in 1990. Should any of us be surprised that the price is rising? There are many places to lay the blame for our current crisis and many different proposed solutions. Figuring out who should be blamed will never be settled and would accomplish nothing. And, unfortunately, you and I have little influence over what the federal government will (nor more likely will not) do on an energy policy. But there is one thing you and I can do, for ourselves and our country. We can slow down and use a little less gasoline. It hardly seems like much of a sacrifice and is an appropriate way to celebrate our independence.

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¹ It may seem impossible that a gallon of gas which weighs about 6 pounds can produce nearly 20 pounds of carbon dioxide, but it is true. For an explanation click here.