A Little Independent Energy Experiment on the Prairie | Science | Smithsonian
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Madelia, Minnesota is a small town with a big plan to produce fuel made from local materials for local markets. (Maggie Koerth-Baker)

A Little Independent Energy Experiment on the Prairie

If you can fight your way through the dirt storms of Madelia, Minnesota, you may be able to find the future of renewable energy

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In the middle of the Minnesota prairie sits Madelia, a town of a little more than 2300 people that is surrounded on all sides by miles upon miles of brown soil, tilled into neat rows. If you flew there in an airplane, Madelia would look like a button, sewn into the middle of a patchwork quilt—each farm divided into fields shaped like squares and circles, bordered by pale yellow gravel roads and by the narrow strips of bright green grass that grow alongside creeks and drainage ditches.

When the residents of a town such as Madelia think about the future of energy, the solutions they come up with are unsurprisingly centered on the land and what it can grow. In Madelia, however, those solutions look a little different from what you might expect. When Madelians imagine the future of energy, they don’t see prairie dotted with big ethanol refineries, where corn grown by hundreds of farmers is processed into fuel that will be sold all around the United States. Instead, they’re thinking about something much more local. Madelia is a small town with a big plan to produce fuel made from local materials for local markets. From the native grasses that easily grow in prairie soil to leftover beaks and pieces from a nearby chicken canning factory, anything that can grow within a 25-mile radius of town is fair game.

Why would a generally conservative town, populated by a lot of generally risk-averse farm families, want to stake a decent amount of time and money on the cutting edge of alternative energy? When I traveled to Madelia, I ran headlong into the reason before I’d even reached the town itself. My moment of enlightenment happened a few miles outside the city limits, on the narrow blacktop of Highway 60, when I came very close to driving my car into a ditch.

The wind had started the day full of bluster, and it was positively furious by the afternoon, while the open, empty fields that flanked the highway offered nothing to slow the wind down. This alone wouldn’t have been a big problem. I grew up in Kansas, and I know how to steer a car through a windstorm. The issue was what I could see ahead of me—or, rather, what I couldn’t see. Out of nowhere, a gray cloud rose up to hover over the highway, swallowing semi-trucks and digesting them into sets of disembodied tail lights. I had barely enough time to realize I wasn’t looking at fog before I plunged into the thick of it.

The sun disappeared. Gravel pinged against the car windows. I couldn’t see anything that wasn’t artificially lit. In a panic, I turned on my headlamps just as I drove out the other side of the gritty haze, back into a normal, windy spring day. The “cloud” was made of dirt, and a mile or so up the road, another gray ribbon of it stretched across the horizon. I went through three or four of these dust clouds before I reached the exit for Madelia.

Even in town, the dust was not easily vanquished. I parked my car downtown, beneath the prow of a movie theater awning, and stepped out into air so texturized you could almost gnaw on it. Flecks of dust stuck in my sun block. When I opened my mouth, grit came in.

I had traveled to Madelia to meet with Linda Meschke, the woman who had become the driving force behind the Madelia Model, and I’d left my house dressed for the occasion, wearing the tidy business-casual wear of a young reporter. Those dust clouds knocked me down a peg. By the time I’d walked two blocks through downtown Madelia, my skin was turning pink, and my hair was a winded red whirl glued into place under a layer of grime. Meschke didn’t seem to mind my sorry state. Instead, she just nodded slowly and said, “It’s a little windy out here today.”

At that point, I still didn’t quite understand what I had seen. Dust clouds such as this, I knew, were related to soil erosion, but it wasn’t until I talked to Meschke that I was able to connect the dots between the dust in my hair and the goals of the Madelia Model.

I found out early on in my research that people tended to describe Meschke brain-first. “She really knows her stuff,” they’d tell me. “She’s a very, very smart woman.” They seemed to be a little in awe of her and a little intimidated, as if she were a force of nature—the opposite of a tornado, she blew through town leaving everything more orderly than they it had been before. From the secondhand accounts, I’d expected to meet a big, brassy Delta Burke of a lady. Instead, Meschke turned out to have the quiet, drawling demeanor of the good ol’ gal farmer she had been for 25 years. She was heavyset with short brown hair, and her tropical-print, button-up shirt was the loudest thing about her, but she really does know how to get the job done—whatever the job in question might be. A former county agriculture inspector, she got involved in rural water-quality issues in 1988. Within a decade, she’d completely revamped the way the counties around Madelia did the work of water protection. Pre-Meschke, the county water programs were all very separate from one another, even if they shared the same watershed. She launched a program that treated the Blue Earth River system—one of Minnesota’s dirtiest waterways—as a single unit, helping ideas and money cross county lines. The big-picture approach led to a 9 percent reduction in pollution by 2001.

The cadence of Meschke’s voice plodded along, but her hands were restless—fidgeting with themselves, drawing little circles on her notepad. She dealt in the small, deliberate details that got public works projects accomplished—the boring stuff for which bureaucracy was basically invented. Yet she talked in the language of a rabble-rouser, about tossing out the old ways and taking risks on new ideas. It was this part of Meschke’s personality that led her to see small-scale local energy as a solution, both to the water-quality problems she’d been fighting for decades and to the threat of soil erosion—which had created the dust storms that plagued my trip to Madelia. Meschke thought that local energy could solve both of those issues, because it could give farmers an opportunity to get paid for growing something other than corn.

Make no mistake, the Madelia Model is about biofuel, but it is not about ethanol. This part of the country needs less corn, not more, Meschke told me. Right now, corn and, to a lesser extent, soybeans are pretty much the only crops being grown. Corn takes up more than 45 percent of all available farmland in southern Minnesota, as well as in parts of Nebraska, Indiana, and Illinois—and pretty much every square inch of Iowa. In those same areas, depending on the county, soybeans chalk up anywhere from 15 percent to more than 45 percent of farmland.

From the outside, this system can seem a little illogical, but it’s simply specialization. It’s no different from a factory making only shoes instead of a closet full of different clothing products. It’s easier to become an expert on two crops, rather than on 20, and you can grow more for less of an up-front investment. Also, frankly, corn and soybeans pay off. There’s a big industrial demand for those plants that broccoli can’t match. When demand falls, there are also ample subsidies to guarantee that farmers make at least a certain price for their crops, with government money picking up the market’s slack.

The downside is that these two crops, and particularly corn, aren’t as great for soil and water quality as they are for farmers’ bank accounts. Corn is a greedy plant that needs a surprising amount of attention to grow. Mainly, corn needs fertilizer and lots of it. In 2007, U.S. corn farmers used more than 5 million tons of nitrogenous fertilizer. Yet while corn may have a big appetite for plant food, it’s about as efficient at “eating” as a toddler with a bowl of spaghetti. You know the kid will end up wearing as much food as she eats, and a corn field will often use as little as half of the fertilizer it’s fed. The rest sits on the soil until it’s washed away into the nearest creek by rain or irrigation.

Corn grows in tidy little rows—with tidy little root systems tucked underneath. In late May, a cornfield is still a sea of dirt, speckled with green shoots not much bigger than your average bunch of basil. When the wind begins to blow, that topsoil doesn’t stand a chance. Since the 19th-century dawn of corn farming, some eight vertical inches of Iowa have gone missing. For people who make their living on what they can grow in topsoil, this is very, very bad. The long-term professional danger to Midwestern farmers is no clearer than when one is picking particles of valuable topsoil out of one’s skin, hair and teeth. The dust storms I’d driven through on my way into Madelia were a product of corn farming. My car was caked in the lost future of U.S. agriculture.

Meschke thought she’d found the key to saving America’s prairie farmland: Third Crops. That was her term for, basically, anything that isn’t corn or soybeans. There was extra credit if it’s native and perennial. Her idea wasn’t unique. Some farmers already use a Third Crop system by rotating fields through corn first, soybeans second, and alfalfa or hay third, which helps keep the soil healthy and reduces the need for fertilizer. Yet Meschke wanted to take this further. First, she promoted planting a wider variety of Third Crops. When a lot of different plants are grown in one region, it becomes less of a Club Med for species-specific pests, which means a decreased need for farmers to buy expensive pesticides. Meschke also wanted farmers to put Third Crops on some land full time, not only in rotation schedules. Land that’s severely nutrient-deficient, land that’s sloped or has a lot of loose topsoil, and land that sits alongside creeks and drainage ditches could all benefit from the dense, water- and soil-retaining root systems of perennial plants.

The trouble for Meschke was how to make Third Crops profitable enough that farmers actually wanted to grow them. The perennials native to Minnesota’s prairie—mostly, various species of tall grasses—are fairly cheap to grow and are ecologically friendly, because they don’t need much fertilizer or irrigation, but they also aren’t worth very much. This was where Meschke’s interest in water quality and soil health dovetailed into her interest in local energy. There’s not really any money to be made in growing Third Crops for topsoil protection or to clean up a polluted stream. Meanwhile, large-scale biofuel production—which currently means corn ethanol—only adds to those ecological problems. You could grow native grasses and turn them into fuel. The technology already exists. In fact, there are many different ways to do the job. The problem is that so far, nobody’s been able to make any of those methods financially viable on a large scale—the kind of system that would allow big companies in the Midwest to produce barrels and barrels of fuel for use all across the country. To most people, that means corn-less biofuel simply isn’t ready for the real world yet. Linda Meschke, on the other hand, looked at that same problem and asked, “Why should people at Madelia worry about whether Florida has enough energy?”

A small refinery that could pay farmers for Third Crops, create some jobs for non-farmers, and produce enough fuel to sell within this one little region of Minnesota would do the trick, Meschke thought. Especially if gasoline prices continued to rise. If that wasn’t viable, she said, you could go smaller still. Even the opportunity to make fuel for their own use—a chance to save money, rather than earn it—could be enough to get at least a few more farmers growing Third Crops. Meschke supports local energy because it’s on the scale that prairie grass biofuel seems to work at, and because right now it offers the best opportunities to set the Madelia Model into motion.

Yet it’s not risk-free. The farms that surround Madelia are large, and they’re commodity-oriented, not a home for boutique cabbages. That doesn’t mean they’re corporate monoliths, though. These farms are family owned, by families who’ve lived in the region for generations. Sure, they might grow only corn. Over the decades, they might have absorbed acreage that used to house a more populous patchwork of smaller farms, but farming is still a family business and a very risk-averse family business at that. It would take three or four years, Meschke told me, to get a perennial Third Crop, such as prairie grass, established and ready for its first harvest. If a market for the grass failed to materialize, farmers would be left with a very pretty field and a big chunk of debt.

On the other hand, if the Madelia Model succeeded beyond everyone’s wildest dreams—if Madelia and the region around it became self-sufficient in fuel—it would drastically change the lives of the people who lived here. Success would change local farming. There would be an economic pressure to start growing new crops that had different needs and different growth cycles. Success would change life in Madelia. There would be new jobs, new businesses, and more consumer choices. Madelia would also be a busier town, with new residents who might be a little better off. Change, like cow pies, happens. How it happened here would depend a lot on whether average Madelians got involved in shaping the future of their community. Their silence on the matter is deafening.

Every fourth Friday at 3 p.m., Meschke told me, the city holds an open meeting designed to bring Madelia Model planners and the public together. It is a noble plan—and mostly theoretical. The meetings happen, but no more than a dozen people ever turn up.

During our interview, Meschke spoke apathetically about the low civic involvement. It didn’t surprise her. It didn’t worry her. I got the impression that were she not the driving force behind the Madelia Model and thus inherently interested, Meschke might be skipping the meetings as well. For all of her mesmerizing confidence, she held no illusions about how the grassroots grows. Most people, she said, were just busy with their day-to-day lives. They’d get interested, but only when the Madelia Model finally gave them something tangible to be interested in. “Right now, what do we have to offer?” she said.

I could see her point. The farmers I knew seldom responded well to maybe/possibly/someday. Either you do something and give us the sales pitch when it’s ready to go, or you don’t do anything, and you shut up about it. (Yoda would have made a great farmer.) “We’ve got the choir signed on,” Meschke said. “And we’ve got a tentative congregation watching to see what happens next.”

This past fall, the Madelians finally got to see some action. Ironically, their first glimpse of the future looked an awful lot like the past. Researchers from the University of Minnesota drove a pickup truck from St. Paul to the farm country around Madelia. Behind it, on a trailer not much bigger than a small camper, they towed a system that could turn just about any kind of plant or animal material into fuel. The technology was new, but the concept behind it was more than a century old.

Beginning in the 19th century, threshing machines traveled from farm to farm during harvest time. A mechanical system for separating grain from its stalk was too expensive to pick out for yourself from the Sears catalog, so the thresher was a portable business. Maybe one guy owned and operated the machinery as his job, or several farmers went in together on a piece of equipment that everyone shared. Either way, farmers paid to have their raw crops turned into something more valuable. The researchers at the University of Minnesota who want to bring a portable biofuel system to Madelia are hoping to repeat that history. Their technology, called microwave pyrolysis, is set to be Madelia’s first shot at making local energy.

The system is both simple and delightfully clever. Pyrolysis is all about breaking down plants and other matter into a form better suited to usable commercial energy. Grasses, stalks, manure—any kind of organic material—goes in. That stuff gets heated to almost 950 degrees Fahrenheit in an oxygen-free environment, thus releasing a host of volatile gases. Condense the gas, and you get a liquid fuel. There are several ways to heat up biomass, but the university’s system is special because it relies on microwaves, stronger versions of the same technology you use to cook popcorn and leftover pizza.

It’s a handy method, because it’s already proven technology—easy to use and cheap to construct. Microwaves also make the entire biofuel production process simpler. Usually, before any biomass can be turned into fuel, it has to be ground into tiny pieces to make sure every bit can be evenly heated at the same time, but microwaves heat up the center of a solid object just fine.

In addition, there’s money to be saved in shipping costs. Moving biomass around isn’t very efficient. Organic material is generally bulky and not very energy dense. Transporting a ton of prairie grasses uses as much energy and costs as much money as transporting a ton of oil, but you get more energy out of the oil. By using microwaves—a heating technology that’s lightweight and can be scaled down to the size of a small camper trailer—the University of Minnesota hit on a way to make pyrolysis portable and bring the fuel factory to the farm. There, each farmer can load up the pyrolysis machine and produce a couple of different products on site. Batch process test runs in the lab took as few as fifteen minutes.

What the farmers get out is useful stuff. Fuel is the main product of microwave pyrolysis. The university’s system does produce enough combustible gas that, once started, it can power itself. In general, though, what you’re making is a liquid called biogas. It’s useable as is, fresh out of the tap, but for best results, it really needs a bit of cleaning up. Any engine will run on fresh biogas, but over time the acidic fuel would tear the engine apart. The university researchers are still working on methods to make biogas compatible with cars, but in the meantime, the stuff can be used in place of home heating oil or sold as a replacement for industrial petroleum.

In the fall test run of the microwave pyrolysis machine, the University of Michigan researchers found some problems with the syngas-powered generator, but they're going to return to Madelia this summer to test the system again with a new generator.

Biogas is not the only important product to come out of the system. Back up to the head of the production line, and you’ll find another output—one that can reduce the quantity of CO2 in the atmosphere and might be able to boost plant growth, too. When biomass is heated by microwaves, the parts that don’t turn into fuel transform into something akin to charcoal. Called biochar, it’s a bit different from standard barbecue briquettes, thanks to the oxygen-free environment where pyrolysis happens.

Biochar functions as a maximum-security prison for carbon. Charcoal can trap carbon, too, but not as effectively. Charcoal is chemically made up of carbon joined to lots of oxygen molecules but is primarily ash and has lost most of its carbon to burning. Like sorority girls in a slasher film, the oxygen is easily picked off by bacteria, which speeds up the process of decomposition, breaking the chemical bonds and leaving the carbon that does remain to drift back into the atmosphere.

Subtract the oxygen, however, and the carbon molecules get tough; they form ring structures that don’t easily shatter and are more resistant to microbial attack. Lab research suggests that these bonds have the potential to hold fast for anywhere from hundreds to hundreds of thousands of years. That means less carbon in the atmosphere. It’s also good news for anyone who’d like to see carbon-neutral or even carbon-negative biofuel production. Of course, that’s in a test tube—there aren’t many biochar studies being done in the (literal) field, and the real-world research hasn’t been conducted for very long.

That’s why—despite lots of crossed fingers—we don’t yet know whether biochar will make as good a fertilizer as it makes a carbon trap. The key question—“Does biochar-infused soil lead to more crops and better soil fertility?”—is still wide open. Yet some tantalizing data are coming out of those lab tests. It seems that by putting microbial life on slow-mo, biochar also works to trap nitrogen in the soil. Not only does that mean less nitrous oxide—another greenhouse gas—in the atmosphere, it could also mean less nitrogen fertilizer applied to the ground and less excess nitrogen leaching away into the water supply.

This is the Madelia Model in a nutshell: give farmers a reason to grow plants that are better for the land and the water supply than corn is, and then reap the benefits. In go prairie grasses, out come fuel, fertilizer, and economic development. It’s not enough fuel and fertilizer to supply the whole country or even the whole state, but that’s okay. It doesn’t have to do that. The primary goal is to prevent more of the local topsoil from blowing away, not to create a mini- empire of bio-oil production. The Madelia Model only has to work on a local scale.

Excerpted from Before the Lights Go Out: Conquering the Energy Crisis Before It Conquers Us, published in April, 2012 by John Wiley & Sons, Inc. Maggie Koerth-Baker is the science editor for boingboing.net.

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