A commentary about corn ethanol published in the Star Tribune this summer was disappointing ("Too much corn is being wasted as fuel," Aug. 12). It failed to make appropriate comparisons and to provide important context.

The author -- Prof. Jason Hill, McKnight land-grant professor in the department of bioproducts and biosystems engineering at the University of Minnesota -- criticized ethanol's supposed negative air-quality effects, but did not mention that gasoline contains carcinogens. Ethanol is not carcinogenic.

He criticized the supposed impact of ethanol on food prices, but did not mention how increased ethanol supplies reduce petroleum prices and thereby hold down a major cost of food production: the cost of oil. He stated that it takes nearly as much energy to produce ethanol as is released when ethanol is burned, but not that we get more than 20 times as much liquid fuel energy from ethanol than is contained in the oil required to make ethanol.

I could go on. Ethanol from corn is certainly not perfect. No fuel is. But if we are to overcome our oil dependence, we need better comparisons between our fuel alternatives.

Perhaps most disappointing was Hill's call for rethinking our biofuels policy. If we reopen the renewable fuels policy discussions, then billions of dollars of capital investment that might otherwise flow into petroleum alternatives (and provide many jobs) will simply sit on the sidelines waiting for the policy issues to be resolved. Achieving our national goal of energy security will be further delayed. Instead, we will continue the status quo of oil dependence, with all of its terrible consequences for our economic security and environmental security.

Why is this important? Because our economy runs on energy: mostly coal, natural gas and especially oil. These energy sources are not renewable. World oil production peaked in 2005, and oil prices spiked shortly afterwards. High oil prices have contributed strongly to our current economic problems.

We know that energy use creates wealth. Energy consumption also improves health and educational opportunities. Thus our health, wealth and level of education are at risk as nonrenewable energy supplies are depleted or become unaffordable. Renewable energy is thus not just a "nice idea." We absolutely must develop it if we wish to have long-term, sustainable wealth and also the improved health and education that prosperity brings.

Energy consumption provides three valuable services: heat, electricity (power) and mobility. Mobility is the capacity to move ourselves and our goods around and also the ability to work from mobile platforms. We have several sources of renewable heat and electricity, including solar, wind and geothermal.

While renewable electricity can provide some mobility services, electricity simply cannot meet the needs for long-haul trucking, ocean shipping and air transport. These mobility applications, and much light-duty vehicle transport, require high-energy-density liquid fuels.

The only renewable source of high-energy-density liquid fuels is plant material. These plant-derived fuels are called biofuels. Biofuels vary greatly in the plant material from which they are made and how they are produced. So-called "first generation" biofuels include ethanol made from corn or cane sugar and biodiesel made from oilseeds or waste grease. Second-generation biofuels are made from nonedible plant materials such as crop residues, grasses and woody materials.

Enough renewable plant material is produced to meet a large fraction of our mobility needs. National policy has encouraged the production of first generation biofuels up to about 16 billion gallons per year. We have nearly achieved that objective.

Our national goal is to follow first-generation biofuels with much larger volumes of second-generation biofuels. A second-generation biofuel industry is now beginning to emerge. About 100 million gallons per year of second-generation ethanol capacity will be in place by the end of 2013.

If we stay the course, this second-generation biofuel industry can grow rapidly, providing energy security, environmental benefits, and the many social and economic benefits that accompany energy consumption. However, a stable policy environment is required before a large second-generation biofuel industry can emerge.

It will take decades to make the renewable-energy transition. So we must be patient. But the longer we wait to make that transition, the more likely it is that both our generation and future generations will be poorer, less-healthy and less-educated.


Bruce E. Dale, is a professor in the Department of Chemical Engineering and Materials Science at Michigan State University.