Last week’s column explored the options for powering vehicles when supplies of imported petroleum and products start to decline. At present it appears that biofuels, natural gas, and electricity are the only alternatives that will be available in large deliverable, quantities in the next ten or 20 years. While biofuels are already in widespread use, it is becoming obvious that turning food crops into fuel is bad policy. Fuels from non-edible plants may provide a significant share of our fuel someday, but that day is still someway off. Many think it will be years and certainly well into the time of oil depletion, before cellulosic ethanol becomes commercially viable on a large scale. Not only does the technology and economics still need to be worked out, but also massive amounts of infrastructure would have to be built.

This leaves us with natural gas and electricity as the only realistic options to power our cars and trucks for the immediate future. It is important to remember that gasoline and diesel will not disappear all at once, but gradually become less and less available over the coming decades and will be accompanied by increasing prices. There will be a period of transition lasting from a few to many decades, during which liquid fuels will still be available but at steadily increasing costs. We live in a country that currently imports about 12 million barrels or two-thirds of its petroleum and petroleum products each day. Given the worldwide trends toward increasing consumption in the oil producing states, it seems likely that most of our sources of imported oil will simply not be available ten or 20 years from now and we will be making do with a third or less of the oil flow currently available.

When talking about the prospects for increased use of natural gas powered vehicles in the U.S. last week, I pointed out that while natural gas had many good features such as compatibility with existing internal combustion technology, an existing widespread and robust distribution system, is cleaner to burn, and mainly comes from U.S. and Canadian wells. The overriding problem is that North American natural gas production has been on a plateau in recent years and all indicators point to declining production in the near future. It is clear that we will never be able to increase production enough to make up for declining oil production.

Some see prospects for large increases in the importation of natural gas from foreign sources. It should be kept in mind that there are already prospects for natural gas shortages in the developed countries. Russian production seems likely to go into decline shortly leading to increased competition for imported liquefied natural gas in the years ahead. Given these realities, a massive replacement of petroleum powered vehicles with ones powered by natural gas seems remote. But what if it becomes a matter of necessity? Natural gas or nothing?

If, as a nation, we are forced to survive on domestic sources of energy, before renewable energy sources come into widespread use, we are going to have to make choices as to how we use our domestically produced fuels. The U.S. currently consumes about 20 trillion cubic feet of natural gas each year. About a third is used for residential and commercial heating. About a third is consumed by industry, either for energy or as the raw material for plastics, fertilizers, and other products, and the final third is used to produce about 20 percent of our electricity.

While there is optimism that in the near future cars and light trucks can be powered by new forms of electric batteries, this still leaves us with the issue of powering our heavy vehicles – large trucks, earth movers, and a myriad of other equipment that currently runs largely on diesel. Given the surge in the world’s demand for diesel, it currently seems likely that the amount of diesel fuel that we can import will be restricted even before our ability to import crude oil and gasoline.

The amount of energy required to run large vehicles and heavy equipment is such that battery-stored electric power is probably not practical for the immediate future. If cellulosic ethanol is not yet commercially viable, then it world appear that natural gas would be the fuel of choice during a transition to renewable energy.

In looking at our current consumption patterns for natural gas, it seems a large scale shift from some current uses for natural gas to replacing diesel would be feasible from both a technical and economic standpoint. WalMart, for example, is already experiment with liquefied natural gas to run its fleet of trucks.

A third of our natural gas consumption goes to produce 20 percent of our electricity. Reducing our electricity consumption by 20 percent should not be difficult. More efficient light bulbs, massive reductions in outdoor lighting and especially turning up the thermostat on the air conditioning, or turning it off, should be a good start. If market forces are not sufficient to bring about the necessary changes in consumption patterns, a change in tax and other polices may be necessary. For governments, decisions to force changes in energy consumption will not be difficult for the choice will be between convenience and comfort vs. survival.

While there is not much of a future for the fossil fuel powered vehicle, during the transition from life as we know it now and a sustainable future, natural gas may well play an important part.

Next week I would like to explore the various possibilities for powering our cars and heavy vehicles with electricity.