Beyond Ethanol

Even people who dismiss the threat of global warming are nervous about a national economy that hangs on the fragile and finite lifeline of oil and gas exports from other countries. So the argument is pretty much over concerning whether the United States ought to wean itself from fossil fuels and move toward a future based on renewable energy.

But alternative energy sources have shown their limitations, too. With solar and wind energy, they’ve always been as apparent as a cloudy or still day. More recently, the boom in corn-based ethanol has revealed the limits on its own growth: How much land can be devoted to cultivating corn? How much corn can be devoted to fuel instead of food? How much groundwater can be tapped for ethanol plants without harming the regional environment? And that’s not even taking into consideration the contention that ethanol costs more fossil fuel energy to produce than it ultimately replaces.

So what fuel will drive the alternative energy future, who will make it, and how will they go about it?

To begin with, make that “fuels,” plural, says Dick Hemmingsen, director of the University of Minnesota’s Initiative for Renewable

Energy and the Environment, a multidisciplinary research center formed four years ago with support from the state legislature. Barring some miracle as yet unforeseen, he says, there will be no single “silver bullet” that replaces fossil fuels as the foundation of tomorrow’s energy industry.

Considering the amounts and types of energy required for transportation, residential, commercial, and industrial uses, “the mountain is just too big for any one renewable fuel source to climb,” Hemmingsen says. To understand the renewable energy future that’s taking shape, think “silver buckshot.”

That means many technologies and fuels—not just the wind-generated electricity and corn-based ethanol that have captured most of the public’s attention and much of the government’s support. The future holds many other types of biomass fuels, new approaches to hydroelectric power, applications of hydrogen technology that don’t require a whole new fleet of cars to be built or a whole new infrastructure of filling stations, even new, clean technologies for fossil fuels like coal.

If diverse fuels is one characteristic of the energy future, synergy is another. Renewable energy sources will supply the power to make other renewable fuels, and they’ll be paired to enhance each other’s benefits or use each other’s byproducts: Synthesis gas, a byproduct of several processes for drawing energy from biomass, can be burned as a replacement for natural gas; likewise, hydrogen can be extracted from biofuels.

Many fuels will also mean localized energy production. The betting among Minnesota’s researchers and entrepreneurs working on energy projects is that we’ll be relying not on a relative handful of huge facilities similar to oil refineries, but on a multitude of smaller plants that draw their resources from a local region and pump money back into it.

Here are five of those Minnesota ventures—some in the research or demonstration stage, some operational businesses—that only hint at the remarkable diversity of what’s happening out there.

Let’s start with bird dung.