There are several avenues that could relieve the situation in the long term, but few that we can deploy now to meet our immediate needs. For example, when we talk about a "hydrogen" solution, we are really talking about a revolutionary technology whose practical application is likely a decade or more away. When we talk "electric vehicles" (EVs) we are assuming that battery and/or super capacitor technology will advance dramatically in the next few years so that auto batteries can be recharged quickly and the driving range between recharges can be extended appreciably.

Then there is the hope that liquid petroleum can be domestically produced from coal or oil shale. Producing oil economically from this country's enormous coal supply is seriously being explored by several private companies with some support of the federal government, but it is still a long way from grand scale commercialization. Oil production from shale, on the other hand, is still in its early development stage and few breakthroughs are foreseen in the near future. Both of these technologies have problems associated with land use, water use, and ecosystem destruction that have yet to be solved. For these reasons none of these technologies appear to be realistic solutions in the near term.

This leaves mainly biofuels, i.e., ethanol and biodiesel. While wide attention is now being given to these fuels as petroleum substitutes, strong reservations have been expressed by some. One of the leading ethanol critics is Prof. David Pimental of Cornell University. He calculates that more energy is required to produce ethanol than the energy achieved. Many have challenged Pimental's conclusions on the basis that his data is badly outdated and that he includes too many irrelevant energy inputs in his calculations. In fact, the US Department of Agriculture (USDA) analysis clearly shows, contrary to the Pimental paper, that U.S. farming and ethanol manufacturing practices are energy efficient and are becoming more so each year. It asserts that the energy content of ethanol delivered to the consumer is significantly larger than the total fossil energy inputs required to produce it. As early as 2002 USDA estimated that ethanol facilities produce at least 1.23 BTUs of energy as ethanol for every fossil BTU expended considering all energy inputs including corn transport, ethanol production, and the distribution and transport of the finished ethanol. This is key since the real goal is to measure how much petroleum is used in the process versus how much petroleum is displaced, not how much total energy is expended.

Still many professionals do believe that a major shortcoming of ethanol is its poor EROEI (Energy Returned On Energy Invested). The ratio today using corn as a feedstock for ethanol is only 1(in):1.5(out) at best. Although this is positive, Prof. Charles Hall (State University of New York) points out that, "expecting to run a country totally on liquid fuels of this low EROEI is almost laughable." Another danger, as warned in Jared Diamond's book, "Collapse," is the possible land degradation that would occur if the enormous acreage needed to produce enough substitute fuel to meet our nation's oil demands is devoted to energy crops. Thus we have a dilemma. The only immediate substitute for oil seems to be ethanol and biodiesel. Ethanol has it limitations as stated previously.

Biodiesel, which is a biofuel made primarily from waste fats or soybeans, can directly replace diesel oil but it too has EROEI weaknesses similar to ethanol. On the other hand, while not the total answer, biofuels can be a substantial contributor (possibly as much as 20%) to our liquid fuel needs and should not be discounted. To really make ethanol a major contributor, however, we need to quickly change our feedstock component from corn to cellulosic matter; i.e., farm waste and especially grown energy crops such as specialty grasses and short rotation woody biomass. The benefit of this is that we would achieve a much higher EROEI than from corn alone and we could grow many of the energy crops on land that is fallow, underused or unsuitable for food crops. It is worth noting that the National Renewable Energy Laboratory in Golden, Colorado, has long been engaged in a research program aimed at developing a practical means of converting cellulosic feedstock into ethanol. In fact, a new ethanol plant in Canada that uses only cellulosic waste as its feedstock has now come on line. It was built by the Royal Dutch Shell company in partnership with Iogen of Canada. More such plants are in the planning stage.

But even at best biofuels alone are not the answer. This country consumes about 21 million barrels of petroleum per day, 14 of which are used for transportation. Currently a NET average of about 150,000 barrels/day (54.75 million barrels/year) is being supplied by biofuels (assuming that only 1 gallon of liquid fuel is required to produce 2 gallons of ethanol -- an optimistic assumption at this time). Even if we increased biofuels production thirty-fold, this would supplant little more than 20% of our petroleum needs (less than one-third of our oil imports today). This in itself is a most ambitious goal, to say the least. It would be unreasonable to expect that we could ever produce enough ethanol to match all or even 60% (amount imported) of our liquid fuel consumption. And even if we could, it is questionable whether this would be desirable considering the enormous amount of land area that would be necessary to produce the ethanol feedstock. Therefore, if we are to solve the total problem we must augment an expanded biofuels production initiative with a dramatic reduction in oil consumption, as much as 7 million barrels per day.

In 2005, the 235+ million on-road U.S. car/light truck fleet averaged 20.3 miles per gallon (mpg); down from 22.5 mpg in 1985. Our commercial airlines, trains, freight trucks, and farm machinery consume gasoline and diesel fuel at an enormous rate. And the amount of oil necessary to produce petroleum based products such as plastics and chemicals is increasing each year. To reduce costs, many airlines are already replacing their old stock with more fuel efficient planes. Many truckers are actively seeking ways to reduce travel miles for deliveries and increasing the fuel efficiency of their trucks.

But the lion's share of the burden must fall upon the private owners of cars and light trucks (which include SUVs and minivans). Some inroads have already been made by the introduction of hybrid gasoline-electric autos which boast mpg ratings of more than twice the average mpg rating of all other cars. And it is further encouraging that many hybrid autos are now being modified so that they can be plugged into any electric power source when the vehicle is idle thereby recharging the batteries without using the vehicle's gasoline engine or regenerative braking system. This increases the mpg tremendously and some hybrid auto manufacturers are seriously considering making this feature an option on future models.

Bottom line -- to make a serious reduction in U.S. oil consumption over the next fifteen years we need to increase the average mpg of our car/light truck fleet from 20.3 mpg to 35 mpg (fifteen years is the average time it takes to turn over our entire light-car fleet today). Therefore, the ideal goal would be to phase in new high-efficiency vehicles to replace all low-efficiency vehicles as they are removed from service over the period. To accomplish this, our federal government would have to carry out a massive public relations campaign, along with an innovative financial incentive program, to convince car owners that it is not only in their own best interest, but in the national interest as well, to change their automobile preferences from SUVs, minivans, and light trucks to smaller, more efficient vehicles. Special rebates should be given to car buyers to purchase hybrid cars and, better yet, plug-in hybrid cars once they become commercially available. In addition, the government will have to gradually impose higher and higher fuel efficiency (CAFE) standards for cars, as well as light trucks, on car manufacturers for implementation over the next decade.

Conclusion

In conclusion, the action we must take NOW to relieve our dependence on foreign oil over the next two decades is threefold: First, we need to increase our domestic oil production from the current level of 7.5 million barrels/day to about 10 million barrels/day. This may mean more offshore drilling, possibly some discrete drilling on public lands, and, if it can become economical and environmentally acceptable, production of oil via coal liquefaction and/or extraction from oil shale.

Secondly, we need to produce more and more biofuels, hopefully as much as a NET 4 million barrels/day. This assumes that a practical method of producing ethanol from cellulosic feedstock will be developed within the next five years and that it will be the predominant method of producing ethanol over the following ten years. It also assumes that there will be a major increase in biodiesel production. These measures will not only provide alternative fuels to relieve much of our gasoline and diesel fuel needs but it also will create thousands of new domestic jobs and greatly improve our balance of trade.

Thirdly, and most importantly, we need to drastically reduce our oil consumption by some 7 million barrels/day. This means an upping of CAFE standards by government edict, a mass manufacture and sale of highly fuel-efficient vehicles, and the subsequent changing some of our life style habits. We can no longer lavish ourselves with large gas guzzling vehicles. We need to replace them with fuel efficient cars and trucks such as hybrid and plug-in hybrid vehicles, and we must learn to economize on our travel in every way we can (car pools, fewer road trips, shorter commutes, greater use of public transportation). In fact, there is a movement afoot encouraging local governments to pass new zoning laws and create incentives for better urban planning of all new real estate developments to ensure less travel between home, stores and places of employment.

These may appear to be near impossible goals, and maybe they are. But we must strive to achieve them as best we can. If we fall short we will still be far ahead of our current business as usual scenario and will reduce our oil imports appreciably. If we delude ourselves that there is no crisis and do nothing, we will be doomed.

About the author...

Paul Notari is currently the Renewable Fuels and Transportation Division representative on the American Solar Energy Society Board of Directors. In 1980, as head of the Technical Information Branch at the Solar Energy Research Institute (now the National Renewable Energy Laboratory), he was the originator and publisher of Fuel From Farms, one of the first textbooks on ethanol production technology. The publication was widely distributed throughout the nation and is recognized as one of the primary movers in the launching of today's ethanol industry.