Chapter 12 ACBAG

CHAPTER 12 - MICRO-DISTILLERY MODEL FARM

BEAR IN MIND, THIS IS ONLY A SNAPSHOT OF A SIMPLE IDEA OF INTEGRATING SOME OF THE CO-PRODUCTS INTO A PRODUCTION SYSTEM. IT IS NOT A FIXED RECIPE, AND YOU COULD FIND ENDLESS VARIATIONS, BASED ON THE MARKETS AND CLIMATE OF YOUR AREA. I'LL USE FISH, MUSHROOMS, AND WORMS AS AN EXAMPLE.

One afternoon, I sat down with my calculator and turned on the permaculture designer part of my mind. What might a farm produce with a micro alcohol fuel plant as its central component? Bear in mind, this is only a snapshot of a simple idea of integrating some of the co-products into a produc­tion system. It is not a fixed recipe, and you could find endless variations, based on the markets and climate of your area.

In permaculture, we have a tradition of failing small and often to learn lessons we can apply on the larger scale, so I am starting this experimental design on a very small scale. To be very conservative, it is based on a micro-plant operating on pur­chased grain (at least initially) and running off a batch every four days. To make calculating easy, I am assuming it will process 1,150 kilograms of corn and will produce 378 liters of alcohol per batch.

We are not using the stalks (corn stover) for cel­lulosic alcohol production in this scenario, but are instead discing them back into the ground to improve fertility. We will use a small fraction of the stover, about 1,100 kilograms, in mushroom cultivation.

In this micro-model, the distillery also serves as a cooker and fermenter, which simplifies the equipment needs. We will also be using an exter­nal heat exchanger and a straw-bale-insulated hot water storage tank as part of the scheme. The flue of the distillery/cooker will have a heat exchanger in it to capture waste heat to be stored as hot water. The condenser will use a heat pump both to chill the alcohol and recapture that heat for a little more hot water. The same heat pump will be used to control the distillery column. The electricity will come from an on-site cogenerator that also heats water. If the plant owner drives a hybrid, this sys­tem will allow him to convert to plug-in hybrid electric, using surplus electricity from the alcohol­ powered generator.

Process heat energy initially will come from waste wood products, such as orchard prunings and broken pallets, but eventually will come from a coppiced woodlot planted to produce firewood. We'll burn the wood waste or firewood in a cob rocket stove to keep the skill level and welding to a minimum. I'll briefly mention how an optional methane digester might be worked into this model, as well.

The distillery model is based on an 20 centimeter­ diameter column, producing 180 to 190 proof alcohol at 60 liters per hour. The alcohol could simultaneously be dried to 196 to 200 proof in a pressure swing com grit water extraction system for dehydration of the alcohol. Although it's not strictly necessary to dry the alcohol to this level, the energy efficiency of this two-step approach is significant.

So there are some things we can observe right away. We will operate the still about 91 times a year, so we'll buy or grow 105,000 kilograms (91 x 1,150 kilograms per batch, or 132 cubic meters) of grain per year to oper­ate the plant. Assuming a yield of 14 cubic meters per hectare, that means we are looking at approximately 9.5 hectares of corn. Over time, this hectarage will go down, and the yield will go up, as we apply what we learned from the experiments in Chapter 3.

Initially, this setup will produce a little more than 34,000 liters of 196 to 200 proof alcohol per year - enough to fuel a mini community-supported energy (CSE) co-op of about 18 vehicles traveling 16,100 kilometers a year at 11.7 liters per 100 kilometers. We will sell the alco­hol at $2.50 per gallon to CSE members and pass the federal tax VEETC (Volumetric Ethanol Excise Tax Credit) of 13.5 cents per liter on to the drivers. The driver's net cost will then be $1.99 per gallon plus sales and road taxes. We'll keep the producer's tax credit of 2.6 cents per liter.

This plant will produce about 33,000 kilograms dry weight of Wet Distiller's Grains, and another three tons of nutrients in the thin stillage, a.k.a. Distiller's Solubles. Although it's possible to use solar energy to dry the Wet Distiller's Grains to Distiller's Dried Grains for storage, here we are using the Wet Distiller's Grains as it's produced. Unlike large alcohol plants, we will not be evaporating the water and condensing the solubles to be mixed with Distiller's Dried Grains.

The plant will also produce 50 tons of carbon dioxide, which we plan to use entirely on the farm. If we could find a local market, the C02 might sell for greenhouse use at $5000-$8000.

From the permaculture vantage point, making alcohol and then selling the feed and C02 would be letting most of the valuable resources leave the property, without extracting all the various yields from these surpluses. If we simply sold the 33 tons of Distiller's Dried Grains wet as feed to a local dairy, we might get only $1500 for it.

Our use of the Distiller's Solubles is a key factor in how we pro­ceed to co-product development. For this scenario, I have chosen to integrate the Distiller's Solubles in both mush­room and fish-raising components. At a minimum, we could use the grain products in our own live­stock operation. We could choose, for example, to convert Wet Distiller's Grains at a dry feed/product ratio of 10: 1 in beef, a 3:1 ratio in chicken, 1.6:1 in fish, or close to 1: 1 for shrimp or earthworms.

I'll use fish, mushrooms, and worms in this exam­ple. Even though I am using wet distiller's grains, I give you what the dryweight ofthose grains would be in order to let you compare apples to apples.

Let's divide our annual production of 33 tons dry weight of Wet Distiller's Grains into three 11-ton parts. The first third of the Wet Distiller's Grains will directly become fish food. At least half of the food that tilapia eat can be Wet Distiller's Grains. The other half must include expensive lysine and methionine amino acid feeds to bal­ance the amino acids in Wet Distiller's Grains - or we can figure out how to produce the needed amino acids on our farm. As you'll see in a minute, a byproduct of what we do with the second 11-ton portion of Distiller's Dried Grains will take care of our fish needs nicely.

The second 11 tons of the Wet Distiller's Grains will be used for oyster andjor shiitake mushroom production. The first step will be to take the Wet Distiller's Grains immediately from the distillery tank at the end of distillation when it is boiling hot and fully sterile. We will separate the granular Wet Distiller's Grains from the liquid Distiller's Solubles in a modified washing machine (modified by chang­ing pulley sizes on the motor and washing drum) on spin cycle. At 250 pounds per run (90 runs per year), using three mesh bags per spin cycle, this would require six five- to ten-minute batches. This process dewaters the Wet Distiller's Grains and leaves us with sep­arate hot Distiller's Solubles.

We will use some of these 900 gallons of boiling-­hot Distiller's Solubles to pasteurize and enrich shredded dry corn stover with the soluble nutrients. We will use about the same dry weight of stover as the dry weight of the second third of the Wet Distiller's Grains ( 1 1 tons) or, to put it in terms of a single batch, a little less than 500 pounds of combined stover and Wet Distiller's Grains. That's about three three-string bales or ten two-string bales. The stover is needed to provide good aera­tion for the mushrooms' growth. We'll add some lime to balance pH. Remember, we have removed most of the carbohydrates from the grain already by fermentation. The carbohydrates that the mush­rooms will eat will be mostly the cellulose in the stover and the small amount of cellulose in the Wet Distiller's Grains. Protein, fats, and minerals are provided by the Wet Distiller's Grains and the Distiller's Solubles.

Mushroom-growing takes two small build­ings, which can be made from ocean shipping containers or, better yet, straw-bale construction plastered with lime. The first building is a clean room (where all the air has been filtered to remove bacteria, etc.), and lhe second building is a spawn-­running room.

The Distiller's Solubles - pasteurized stover and lhe hot Distiller's Dried Grains are mixed on a table by hand in lhe clean room until the mixture cools to below 90°F. We lhen inocu­late the stover/Distiller's Dried Grains mixture by mixing about ten pounds of oyster or shiitake mushroom spawn into the mass as it is packed into plastic bags. The spawn is laboratory-raised fungus on grain that is grown through with mycelium. The bags are then closed wilh a breathing device that lets gases exchange from the bag, but keeps bacteria out.

The bags then go on racks in the spawn-running room for the next two weeks. This room can be kept warm by running the warm water recovered from the alcohol plant through radiant heating tubes in the floor. The two weeks in the spawn-run­ning room allow the mycelia of the mushrooms to branch out from the spawn particles to digest much of the Distiller's Dried Grains/stover substrate. The content of the bags will take on the appearance of dirty cotton.

After the mycelium has fully grown through the mix, the bags are moved to a cooler, more humid, fruiting room. The bags are slit to let out the CO2 and to let the oxygen in. These new conditions imi­tate the onset of late fall, which induces fruiting of the mushrooms through the slits made in the bags. The mushrooms are then harvested over about three weeks' time.

The 22 dry tons of mushroom substrate (com­bined stover and Distiller's Dried Grains) will produce about 22 tons of fresh oyster mushrooms (wet weight) annu­ally, or a little less than 500 pounds per week. At a wholesale price of $2.50 per pound, the gross income for the 22 tons of mushrooms would be $ 110,000. Sure beats selling the Wet Distiller's Grains as cattle feed. Any mushrooms not meeting the cosmetic standards of the market can be fed to either the fish or earthworms.

Roughly half of the 22 tons of dry matter of the stover/Distiller's Dried Grains that we started with, has now been used in producing the mushrooms. The spent mushroom substrate, now about 11 tons dry weight (although it is in a wet form), is essentially almost fully converted to mushroom mycelia. Whereas the original plant matter was low in the amino acids methionine and lysine, the process of growing the mushrooms rearranges the ratios of amino acids. We will return to using this surplus product in a moment.

So the first 11 tonnes of Wet Distiller's Grains became fish food. The second 11 tonnes of Wet Distiller's Grains were mixed with stover and turned into mushrooms. The last 11 tonnes of the Wet Distiller's Grains will go into specially built "livestock" pens.

As a permaculturalist, I am allergic to extra work, since it usually indicates poor design. I often tell my students who want to raise livestock that, with a few exceptions, you are never going to have a vacation again, because those animals depend on you every day to keep them in line and alive. An exception to this rule is earthworms (see Chapter 11).

Part of the plan for this small plant is to build special bins that functionally optimize the production of worm castings (worm poop) over worm production. Although it's entirely possible to include worm production for worm sales, we will keep things simple in this example by leaving out that particular yield and focusing on the castings. Earthworms are more efficient by far than chickens or fish. There is close to a one-to-one ratio of dry weight of food eaten to weight of worms produced. But once the worms are mature, most of the feed goes to produce castings. Conversion of the 11 tonnes of Wet Distiller's Grains dry weight at maximum saturation of worms (see Chapter 11) would yield about 22 tonnes of castings at their normal finished moisture content of 50%. It is not desirable to dry worm castings much below this, since it would kill much of the microlife that makes castings so valuable.

Remember the leftover 11 tonnes of mushroom substrate, after we harvested the mushroom? If we take half of the spent mushroom substrate (5.5 tonnes) and feed this to worms, they will convert this fungal delicacy to another 11 tonnes of castings for a total of 33 tonnes of castings. (Or we can use all this spent substrate elsewhere. Bear with me here.)

Although worm castings are often sold by volume, e.g., cubic foot or cubic yard, a growing number of producers are selling by the pound; prices range from between $1 and $1.90. So 22 tonnes of worm castings should be worth, retail, $44,000 to $83,600. If we include the castings from conversion of spent mushroom substrate, 33 tonnes would be worth $66,000 to $125,400. You can expect to sell your castings at half this price wholesale, if you sell by the tonne or cubic yard to a nursery supply.

In the states where medical marijuana is now legal, your best retail customers for organic castings could be the growers of this medicine. They are a very good retail market, especially if you also supply fish emulsion, carbon dioxide, and kelp solution. And they pay cash too!

So far we've converted the Wet Distiller's Grains into worm castings, fish, and mushrooms. We still have a quarter of the spent mushroom substrate to consider. We will use that material to feed our livestock: tilapia.

Our fish's diet can be half Distiller's Dried Grains, but for the other half, we need to add the nutrients the fish need in addition to the Distiller's Dried Grains. We can eliminate the cost of this supplemental feed (typically soybean meal) by feeding the other half of the spent mushroom substrate to them instead. So now the fish diet is 11 tonnes of the Distiller's Dried Grains and about 5.5 tonnes dry weight of mushroom mycelium made of Wet Distiller's Grains/stover.

This 16.5 tonnes of feed at a conversion rate of 1.6 to 1 yields about 20,000 pounds of live fish biomass. About 45% of fish sales will be the 9,000 pounds of full-size male fish for food, delivered in an oxygenated tank truck to nearby city restaurants. We can reasonably expect to get $7 to $10 per pound for this 4.5 tonnes of fish. That would mean the live fish income stream would yield a gross of $63,000 to $90,000.

The other 55% of the tilapia will be close to 11,000 pounds. These are the females and culled fry, which currently don't have a market. These can be converted into fish emulsion. It takes about a pound of fish to make a gallon of fish emulsion. So let's be conservative and say these 55% will yield about 10,000 gallons of fish emulsion. This would be worth almost $120,000 if sold in five gallon pails. But sold in one gallon bottles at $17.50, it would be worth $175,000. If you sold it in quarts, the price would go up to $6.95, for a whopping $278,000 retail. You could wholesale these products for 1/2 retail price, if you don't want to market them yourself - although you could easily sell all of your production at a booth at a farmers' market, along with your vegetables.

How much space would fish raising take? This quantity of fish could easily be raised in two 32,000 gallon tanks or, better yet, ponds inside a standard 30x100 foot greenhouse with two crops of fish per year. You could add another tank of or two of this size to take advantage of algae and duckweed production as an additional or alternate fish feed.

Let's take the model micro-distillery farm idea a little further, make it a little more complex and interesting. Remember the liquid Distiller's Solubles we still have unaccounted for? We used some of it right away when we soaked the stover for mushroom production in it, but we still have most of it left. Since it is already liquid, we might as well figure out a way to use it with our fish.

As we said in Chapter 11, one way to feed fish without even using Distiller's Dried Grains is by raising massive quantities of algae. The limiting factors on algae growth are similar to those for land plants. We need to supply nutrients, sunlight, and carbon dioxide for a healthy algae population explosion, and if any one of the three is in short supply, then that will limit production. We can't do a lot about increasing the sunlight, but sunlight is not usually limiting. If we use Distiller's Solubles as a nutrient source in the algae pond, we're okay as far as nutrients go. But even though the algae would have ll the food and sunlight ntey'd need, they would quickly use up all the carbon dioxide in the water, so that would limit produciton. So we need more CO2.

The carbon dioside can come from three sources. One source, of course, is the fishpond. The fish have been breathing in the oxygen in the water and "exhaling" the CO2 into the water. So their pond has a surplus of carbon dioxide in the water that the algae would lust for (if algae had such thoughts). Circulating the fishpond water into the algae pond would do double duty, adding not only CO2, but also removing and converting surplus nutrients (fish poop).

But even if we recovered all the CO2 that the fish make, we'd still be quite short. That's where the second source of carbon dioxide, fermenting alcohol, comes into play. The CO2 pouring out through the fermentation locks on the still/fermenter can be bubbled into the bottom of the algae tank. If we do this, together with all the Distiller's Solubles and some of the pond water, the reproduction rate of the algae will go through the roof.

The algae growth oxygenates the water, producing a massive oxygen surplus, and eliminates the oxygenating costs of normal fish farms, where they usually consume huge amounts of energy running various sorts of bubblers. The green, algae dense, oxygen rich water is slowly pumped over to the fishpond, oxygenating it and feeding the fish even more tasty food and carbohydrates.

This process uses the nutrients in the Distiller's Solubles, via carbon dioxide and sunlight, to produce several more tonnes of fish food, which would give you lots more fish to sell. This photosynthesis only happens during the daylight hours. At night, we would capture the CO2 from nighttime fermentation, clean it, and compress it (see Chapter 11) for use the next day.

If we were to add methane production to the simple plant, it would be our third possible source of carbon dioxide. Instead of using the surplus Distiller's Solubles to produce more fish food, we might first run the Distiller's Solubles through the methane digester to extract carbohydrate energy as natural gas, and then use the outflow of the methane digester to fertilize the algae. (The conversion of Distiller's Solubles to methane is standard practice in India.) The gas from the digester is 60% methane and 40% carbon dioxide. The process of cleaning methane in a water column dissolved the CO2 into the water, which can be used as makeup water for the algae pond. This would make a lot of sense if you didn't want to use wood for process heat in your alcohol plant. The Distiller's Solubles can produce enough methane to do all the heating and even produce electricity as a generator fuel for the plant.

Let's say you don't want to do something so intricate. You just want to feed the Distiller's Dried Grains to the fish and harvest the fish and not get all involved in this algae/carbon dioxide complexity. After all, the extra cost may not be worth the hassle if you don't have local markets where you can sell the fish or fish emulsion.

Let's look at the alternative. If we feed all this tonnage of high protein Distiller's Dried Grains feed to the fish, they are going to eat it and poop out a very high percentage of it. As much as 70-90% of the nitrogen is excreted, depending on where they are in their growth cycle. Fish water is loaded with concentrated nutrients and ammonia. In fact, the fish would die if the water wasn't changed or processed.

One use of the fish water is to pump it and the Distiller's Solubles into low-value corn or other energy crop fields, where it would provide all the fertilizer for the next crop needed for next year's fuel. This assumes you turned the cornstalks or bean trash back into the soil at the end of the season. The combination of organic matter and fish water actually increases soil fertility and soil depth each year.

If you choose not to raise surplus algae, all of the 50 tonnes of surplus carbon dioxide could be piped into an attached greenhouse to rapidly grow high-value, off-season fruit or vegetables, such as strawberries, cucumbers, or tomatoes. The quantity of CO2 from this micro-sized project could be used intensively in three to four standard 30 x 100 foot greenhouses (see Chapter 11).

So let's assume we are combining some fishpond soup, a small quantity of the leftover earthworm castings, and the carbon dioxide in greenhouses filled with raised beds. It would be simple to produce organic vegetable yields of three pounds per square foot, per plant cycle, of densely planted complimentary crops. Furthermore, bottom heating of the soil via radiant heating tubing can profitably use the lower temperature surplus hot water from the plant. Three crop cycle can be easily completed in 11 months.

So that's 9 pounds per square foot per year of raised-bed space. In three standard greenhouses, there would be 7,200 square feet of crop area out of the total 9,000 square feet (taking into account 20% used for paths between raised beds, and a 200 square foot staging area). With a focus on high value organic salad mix, tomatoes, cucumbers, or strawberries, the annual yield could easily be 65,000 pounds.

At retail prices of $2 to $4 per pound, you are looking at $120,000 to $240,000 of organic vegetable sales (on top of your fish sales). The farther away from California, the higher the average price will be.

Sound too good to be true? One of the most productive farms in the United States made far more money than this on organic salad mix, in a city lot in Berkeley, California, without all the luxurious and controlled conditions we're outlining in this system. In a similar sized greenhouse in New England, Anna Edey and her integrated livestock and greenhouse projected at full capacity earnings of $180,000 in eight months producing salad alone, without most of the advantages of an alcohol derived greenhouse. (She did some CO2 enrichment by housing animals in the same air space as the vegetable operation.)

While I am conservatively projecting three crop cycles, it should be noted that Archer Daniels Midland greenhouse in Decatur, Illinois, gets more than ten crops of lettuce per year, as do some coastal California lettuce farms without any greenhouses. Pushed to the limit in a highly organized CO2 enriched greenhouse, you could turn over a salad mix or head lettuce crop every 20-25 days.

Still sound like too much work? Then let's look at a really basic setup. Using inexpensive drip irrigation tubing, you can pump filtered freshwater and carbon dioxide into your fuel-wood forest and energy crop fields, which would not only increase the yield of wood for fueling your distillery and eliminate the cost of fertilizer, but also increase the soil fertility and energy crop yield over time (see Chapter 3). So to keep operating the system using your own corn or wheat (wheat provides handy straw instead of stover), you'd end up having to farm less land in order to get the same yield, and also make alcohol, and to produce value-added crops of mushrooms, fish products, high value veggies, and earthworms.

To cut costs with our microdistillery, there are a lot of ways to provide process heat for cooking and distilling by making use of the low-quality warm water that comes out of the plant. We mentioned above that the Distiller's Solubles (along with other surpluses) can first go into a methane digester, heated with hot water coils. If, for instance, you are raising chickens on the mushroom waste and surplus worms, the chicken manure and bedding can go into the digester too. Local surplus deep-fryer grease makes huge amounts of methane when mixed with Distiller's Solubles. Culled tilapia can be put in the digester as well, even though it is more profitable to make them into fish emulsion (see Chapter 11).

In any event, you should be able to produce more than enough methane to do all your distilling, cooking, and electricity production. Surplus warm water is useful for heating greenhouses, tilapia/spirulina ponds, mushroom houses, methane digesters, and buildings.

If you want to fire your plant with wood instead of methane, and if you have space, you can use part of the solubles and/or fish water to irrigate a fuelwood forest. Providing firewood for process heat to make 9,000 gallons of alcohol would take about 270 million Btu from wood. This amount of heat can reasonably be obtained from seven cords of wood (each stacked 4'x4'x8'), weighing somewhere in the neigbourhood of two tonnes per cord. Raising the wood sustainably with renewal pruning (coppicing) would take about 1 1/2 acres of woodlot. Of course, the understory of the 1.5 acres of woodlot could produce crops of strawberries, blueberries, hazelnuts, currants, flowers, raspberries, greens, etc., if you chose to expand into outdoor crops.

Here's how to use coppicing to grow high quality firewood: Establish four major branches, or main leaders. Cut the oldest of the four branches each year. The four-year old branch should be perfect stove wood diameter and not need any splitting (extra work to be avoided). When multiple sprouts shoot out from the cut in the spring, pinch back all but one to replace the branch that was cut. In four years, you will have another full-sized branch to cut from that shoot. Each year, cut the oldest leader.

Coppiced woodlots work well with dense, hard, fast-growing, nitrogen fixing leguminous trees or even fruit trees. According to Bob Cannard, master farmer and orchardist in California, using this coppicing technique has resulted in apple trees producing for 600 years in Siberia and olive trees still producing after 1,000 years in Greece. He's also able to prune 25 acres of apple trees in a few days with this efficient method.

All of this is a simple example of permaculture thinking on the micro-plant scale. We can do much more complex stacked designs. Just think about what it would be like if we added a few fermentation tanks, a cooker, and a slightly larger still, so we were running one shift each day, making 60,000 gallons a year instead of 9,000 gallons.

The major point of this short exercise is to help you realize that alcohol production should be a part of an overall diversified farm design. Furthermore, we need to realize just how obscenely wasteful it is to put 20 btu of fossil fuel into each Btu of grain, and then take ten Btu of grain to feed cattle in feedlots to get only one Btu of meat, only to poop almost all of that energy away in mountains of ground-poisoning manure.

Since basic variations on the model farm could be accomplished, depending on complexity and climate, with perhaps 5 to 40 acres, the average Midwest farmer who controls hundreds, sometimes thousands of acres is going to have a lot of extra land on his hands. In most places, the model becomes even more efficient when we start designing with crops other than corn.

Permaculture wisdom totally changes the modern day question of how many square miles can one person farm, growing monoculture crops; the new question is how many good jobs for how many people can we produce per acre with energy/food polycultures? You can see we'd have a big crew making middle-class wages if we had a complex permaculture design, making sure we got every yield possible out of whatever feedstock we chose to make alcohol from.

So what do the nubmers add up to in a model micro-farm? In this simplified version, our main products are alcohol, fish, fish emulsion, mushrooms, earthworm castings, and high-value greenhouse vegetable crops. Surplus Distiller's Solubles would go out as fertilizer along with surplus fresh water, to provide all the fertilizer we need for next year's energy crop and wood for process heat. The estimated gross receipts of $484,000 are detailed in Figure 12.7

Alcohol

- 9,000 gallons

- $2.50/gallon

- $22,500 Gross value

Mushrooms

- 44,000 lbs.

- $2.50/pound

- $110,000

Worm Castings

- 33 tonnes

- $1.00/lb wholesale

- $66,000

Live Fish

- 9,000 lbs.

- $ 7.00/lb.

- $63,000

Fish Emulsion

- 10,000 gallons

- $6.00/gallon wholesale

- $60,000

Greenhouse Veggies

- 65,000 pounds

- $2.50/pound

- $162,500

TOTAL - $484,000

These are the gross figures, of course. A lot of labour would be involved in handling this much production, and that's a good thing. We can generously assume the nonlabour costs of production and marketing are 25% of the gross. That's $363,000 dollars available for labour and profit. Ten good rural incomes would be met by this amount, even if the labourers only worked about 25 hours a week.

And this is a simple permaculture design. There are much more complex and remunerative layers of production that can be built onto this simple model. A somewhat larger plant, producing 200 - 300 gallons 325 days per year (65,000-97,500 gallons) would take very little additional equipment, but the number of opportunities and complexity of products would multiply. What's more, the density of jobs per acre would go up.

So is it more efficient to produce alcohol in 50-million gallon per year plants that have only one or two low-priced co-products? It depends on what you call efficiency. If you are trying to make the most alcohol with the least number of people, then maybe a big plant would be more efficient. If efficiency is defined as producing the most money from a given tonne of corn, maybe wet mill corn biorefinery plants can do better.

But when it comes to how much money you can produce from an acre of energy crop, being small enough to get full retail from your value-added products sold locally makes the small scale far and away more efficient than large plants.

A most important yield is the number of jobs per acre you can create. If you look at the maximum number of farmer-owners who can make a good living on such an integrated farm, there is no comparison; large plants barely produce one direct alcohol plant job for every million gallons of alcohol and increase the price of a bushe of corn by only 20 cents. Yes, alcohol plants do circulate a lot of money into the local economy, and that creates jobs. But our small model farm can produce several good jobs for every 9000 gallons of alcohol produced, and circulate even more money locally.

In the long run, large plants cannot compete with smaller, multiple-yield, multiple-feedstock, permacultarally designed plants when it comes to benefits to a state and its people. Right now, there are places for all sorts of production scales in a national system of combined energy/food production. As time passes and the concern over energy is no longer price, but whether it is even available - decentralized, local production of fuel and food becomes vitally important. We should fill all the niches at each level of fuel production until we are energy-independent, self-sufficient in food, and fully employed.

Now that your head is spinning with the possibilities of all the products that can issue from your plant, it's time to refocus on alcohol. After all, that's what got us into the whole discussion to start with. Although it may not turn out to be the most profitable part of your enterprise, alcohol is the core product, and understanding how to use it is essential whether you're selling it or making it part of your own energy supply. We'll start by hitting some of the surprising high points and bust a few myths in the process.