Is Public Transit the Answer? It depends

(This is a response to Blackadder’s recent post: Is Public Transit the Answer? Don’t bet on it)

The wrong basis

The graph that Blackadder had on his post suggested that light rail consumes more BTUs per passenger per mile: that is, more than a car. Such numbers would suggest that in terms of energy consumption, the light rail does not stand as a better option to an individual car. As I said in my comment on his post, the graph in itself is ambiguous and misleading, because it is ranking forms of transportation solely on the basis of BTUs consumed. The graph’s main argument falls apart, because not all the forms of transportation noted are powered by the same fuels. Light rail, for instance, is powered by electricity and that electricity can come from different sources: coal, water, wind, nuclear, etc. Cars, on the other hand, are powered by gasoline or diesel. If a light rail in the northeast consumes, say, 100 MMBtu/hr of electricity that comes from coal and another light rail in California consumes the same amount of BTUs, but the source of electricity comes from wind, the negative net effect of the former on the environment (from coal extraction to emission greenhouse gases) is much greater than the latter. As noted in a post written by Christian Peralta from the Planning and Development network, “light rail beats the average car only in some cities — mainly where electricity doesn’t come from coal or oil.” So the question is not to be poised in terms of BTUs, but rather in terms of the fuel source. Thus, the only way that the graph can stand is if all the forms of transportation noted are on the same fuel basis. The crucial question that is missing from the graph and that most people will not ask is: what fuel are you burning? Natural gas? Coal? Fuel oil? Diesel? Gasoline? Steam? 1 BTU burned of fuel oil will be much more polluting and will emit more CO2 than, say, natural gas.

Alternative fuels

When we talk about alternative fuel sources, we are not trying to reduce the amount of BTUs, really. We are only trying to replace the source that will provide the same BTUs. Energy is energy and if you need a 600 MW power plant, you’re stuck: that’s what you need. The question for the design engineer to answer is what will be the source of energy to power that power plant that will be clean and economical. Will it be a 600 MW coal plant? A 600 MW hydro plant? A 600 MW wind mill? 1 MMBtu/hr obtained from burning coal are equal to 1 MMBtu/hr obtained from a wind mill. However, the net effect of the former on the environment is obviously more negative than the latter.

Global Warming and High Gas Prices

If we are really concerned about global warming or high gas prices, the BTU basis is the wrong way to go. With regard to global warming, our aim should be to move toward fuels that burn cleaner and release less CO2 not to move from a fuel that burns less BTUs than another, because then that would force us to decrease consumption. Although less consumption is our ultimate goal, the driving force toward migrating to alternative fuels are not BTUs but rather to find fuels that will provide the same amount of BTUs as fossil fuels but that will 1) burn with less CO, CO2, SOx, NOx, etc., as undesirable byproducts of their combustion and 2) will be economic enough to burn (i.e. the amount needed of the alternative fuel remains economically feasible). In other words, ideally, we would find an alternative fuel that would prove to be economically feasible to burn while providing us with the same BTUs as, say, coal, but with diminished environmental impacts.

With regard to high gas prices, well, BTUs have nothing to do with it. Gas prices are primarily affected by supply and demand, as we all know, but also by local taxes and regulations on the fuels. The latter require that gasoline/diesel be treated for removal of nitrogen and sulfur and that they also be blended carefully before leaving the refinery with additives that allow for a cleaner burn. Hence the higher gas prices in California when compared to Texas. The air quality regulations in California are much more stringent than those in Texas.

Conclusion

If mass transportation can be powered with cleaner fuels that will decrease or eliminate net negative effects on the environment, then it does remain an attractive solution. We also need to remember that there are many factors that justify mass transportation and have done so abroad: improves traffic, provides transportation to those who cannot afford a car, more convenient, efficient and faster, etc. (How many books wouldn’t we all go through with somebody else driving for us!) Hence, we cannot say as Templeton claimed that “[W]e would get more efficient by pushing small, fuel efficient vehicles instead of pushing transit, and at a lower cost.” Templeton, in my opinion, is missing the forest from the trees. Ask anyone here in Houston if they want to drive their car or would prefer to take a train or a bus and you will see an overwhelming majority going for the mass transportation. Traffic is terrible here and it is a waste of time. It would not be efficient (nor feasible) as Templeton suggests, to have a lot of small, fuel efficient vehicles on the road. Traffic jams would be worse than they are in all major U.S. cities. Obviously, the problem of increased gasoline consumption would not go away with his suggestion either. Remember, when we talk about gasoline consumption we do not mean it in terms of BTUs but rather in terms of barrels. And barrels are the ultimate indication of consumption that drives the markets. Different fuels have different heating values (BTU/lb), so the higher the heating value the less fuel you need to power a set amount of energy. That is why in the industry, we never speak in terms of BTUs (because they are already implied and are specific to the fuel). We only speak in terms of barrels.

The answer is, then, not in terms of BTUs but in terms of cleaner fuels.