Wind and Ethanol
Wind and Ethanol: Economies and Diseconomies of ScaleJohn Farrelljfarrell@ 2007A publication of the New Rules Project of the Institute for Local Self-Reliance1313 5th Street SE, Minneapolis, MN 55414?
Wind and Ethanol
AcknowledgmentsI want to thank my colleagues at the Institute for Local Self-Reliance, and especially David Morris, for their assistance and counsel. I appreciate the very helpful feedback offered on earlier drafts by Mark Bolinger, Paul Gipe, Dan Juhl, Charles Kubert, Mike Michaud, David Swenson, Pat Westhoff and Paul White. Of course, any shortcomings in the nal product are solely my publications from the New Rules Project of the Institute for Local Self-Reliance:
Energizing Rural America: Local Ownership of Renewable Energy Production is the Key
by David Morris, April 2007
Lessons from the Pioneers: Tackling Global Warming at the Local Level
by John Bailey, January 2007
Big Box Swindle: The True Cost of Mega-Retailers and the Fight for America s Independent
Businesses
by Stacy Mitchell, November 2006, Beacon Press
Climate Neutral Bonding: Building Global Warming Solutions at the State and Local Level
by John Bailey, February 2006
The Carbohydrate Economy, Biofuels and the Net Energy Debate
by David Morris, August 2005
A Better Way to Get From Here to There: A commentary on the Hydrogen Economy and a
Proposal for an Alternative Strategy
by David Morris, January 2004All available at '2007 by the Institute for Local Self-Reliance. All Rights ReservedThe Institute for Local Self-Reliance (ILSR) is a nonpro t research and educational organization that provides technical assistance and information to city and state governments, citizen organizations and 1974, ILSR has researched the technical feasibility and commercial viability of environmentally sound state-of-the-art technologies with a view to strengthening local economies. The Institute works to involve citizens, governments and private enterprise in the development of a comprehensive materials policy oriented toward ef ciency, recycling, and maximum utilization of renewable energy Of ceWashington DC Of 5th St. SE927 15th St. NW, 4th FloorMinneapolis, MN 55414Washington, DC 20005612-379-3815
and Ethanol
Wind and Ethanol: Economies and Diseconomies of ScaleJohn Farrell, Institute for Local Self-RelianceJuly 2007Introduction WindLarger renewable energy facilities tend to generate For a single turbine, the potential output and unit cost energy at a lower unit cost. This is why the rated ca-are based on many factors: turbine hub height, rotor pacity of a typical wind turbine has increased from 25 diameter, and wind speed. Siting and design of tur-kW in 1981 to MW today and the output of a typi-bines can signi cantly impact the ef ciency and, ulti-cal ethanol plant has increased from 40 million gallons mately, the cost of power from a wind turbine. For in 2002 to 100 million gallons in turbines, other ef ciency issues arise, such as distance between turbines, interconnection to the elec-However, larger production units also impose poten-tric grid, and transmission distance to the ultimate cus-tially signi cant social costs. The most signi cant is tomer. that bigness encourages, and often requires, absentee ownership. This reduces or eliminates the many bene-Economies of Scale 1 ts that accompany a locally owned facility. Bigness also requires much longer distribution systems for both There are three ways to lower the cost of energy from a inputs and outputs, generating environmental as well as single turbine. social costs. 1. Increase the height of the turbine hub. A rule of To date, policy makers have designed renewable en-thumb is that wind speed increases by the 1/7th power 2ergy incentives that offer higher rewards for bigger of hub height. If a Vestas V66 1650 turbine produced facilities. They should more closely examine the power at 6 cents/kWh, doubling the tower height tradeoffs attendant to large scale production systems. would cut the production cost by approximately 1 cent/3This report argues that the net bene ts to society from kWh for each scale production may not outweigh the costs 2. Increase the diameter of the rotor. Power generation from limiting the potential for locally owned energy facilities serving regional needs. increases by the square of the increase of the rotor 4diameter. Doubling rotor diameter from 40 to 80 m, for example, could reduce power production costs by about 75% (from 6 cents to cents/kWh in our hypo-Reduction in power production costs from a thetical example).doubling of tower height and rotor length, and a 25% increase in wind . Install the turbine a windier location. The power in the wind varies by the cube of the increase in the wind 75%5speed. Doubling the windspeed thus theoretically 75%increases the turbine power output eightfold, though in 37%50%practice turbulence and other factors constrain it. Ad-17%25%ditionally, wind speed variation between sites is usu-ally modest. For example, the average wind speed for 0%a Class 4 wind area is only about 21 percent higher - Tower heightRotor diameterWind speed
W4ind and Ethanol
meters per second (mps) vs. mps - than a Class ing 60%. These reductions are more signi cant as 83 wind area. That difference would lead to a reduction size scales up. in the cost per kWh of about 34%. On the other hand, higher wind speeds can be found on only a limited As wind power continues to grow in prominence, how-acreage and sections of the country. Moving from ever, some of these economies may decrease. Data Class 4 to Class 3 might increase the amount of acre-from Denmark — generating nearly 20% of its electric-age and therefore ity from wind — suggests that the cost savings to large potential sites avail-projects may decline as wind power gains greater mar-Component Cost of MW able several fold. ket penetration, and maintenance services are more and MW Wind Project 9Thus the tradeoff for widely available. Shared cost savings can also be 100%the higher cost elec-realized with cooperative models like the retail sectors tricity that comes Ace Hardware cooperative, where purchasing and ad-75%from siting on lower vertising costs are pooled among speed areas ver-50%sus the higher trans-A nal advantage to scale is that attracting nancing mission costs of siting may be easier for large wind farms. Corporate nan-on more remote wind-ciers of wind projects are not often interested in small-25%10ier areas becomes scale turbines or wind farms. They seek projects with important. We ex-substantial generating capacity that can spread the risk 0%plore the transmission and xed costs over many turbines. MWline issue in more TurbineDiseconomies of Scaledetail below. Site developmentInterconnectionUnit cost savings can Perhaps the biggest single diseconomy of scale arises Soft Costsalso occur by con-from transmission costs associated with large projects. structing and operat-Small wind projects can use the power generated on-ing multiple turbines. 11site or can offset retail purchases via net metering. Construction costs are lower per kW since larger pro-Large wind projects almost always exceed on-site jects can buy components in bulk and spread construc-needs and net metering limits — only eight states allow tion costs, legal and permitting fees, and nancing over 12net metering over 100 kW. Moving power to distant 6multiple turbines. Bolinger, et al, nd a 30% reduc-customers often means constructing new high voltage tion in site preparation and soft costs per kW for a 1314transmission many projects are located MW project over a single MW turbine. Over-in rural areas with little local load (demand), they re-all, the MW project is approximately 10% cheaper quire substantial upgrades to the existing transmission per MW installed, with soft cost savings making up system to get the power to market. 40% of the reduction and site preparation the remain-In one study modeling the connection costs for four different wind farms to six urban areas, transmission Levelized Cost of Electricity costs — including substation upgrades — increased by Relative to a 10 MW Wind Farm about cents per kWh for every additional 100 miles (not including transmission)15of line. An average of 13 percent of the lines were 100%rebuilt, the vast majority were new construction. Thus 92%100%74%a 500 mile delivery could cost cents per kWh more 75%than a local %25%Long distance transmission also results in higher line 0%losses. The combination of transmission and conver-10 MW sion losses reduce delivered power by approximately 1 Baseline50 MW200 MW16percent per 100 miles. For a typical project studied,
and Ethanol
delivered costs increased by about single, smaller turbine may avoid Remote Generation is cents per kWh per 100 miles of Wind sites relatively close to the load, even certain costs. Legal costs depend though they have much less energy poten-transmission, or about .15 cents per heavily on the number of turbines tial than the high wind sites in the region, kWh for a 500 mile delivery trip, on and landowners involved. A single can be more economical in many top of the cents noted -operator with one turbine can cases...The carrying charges on the expen-sive HVDC system [used for long distance avoid legal and permitting fees transmission] typically add about $15 to 21Another drawback of large wind (about $20/kW).$20 per megawatt hour to the bus bar cost farms is the interference between the of the remote wind generation. wind turbines. This interference, Maintenance can be both a disecon-Source: Factor and Wind, array losses, is caused when omy and an economy of scale. turbines are in the wake of other Larger wind installations can spread turbines. Research differs on the full effect of array maintenance costs over many turbines and experience losses. More recent assessments cite the losses of smaller reductions in capacity from single-turbine out-modern wind projects at 2-4% with properly spaced ages. However, these advantages are more pronounced 17turbines. The Department of Energy has the most in wind farms with smaller wind turbines, because the nuanced research, estimating that turbine arrays in impact of an individual turbine outage is a smaller per-Class 4 wind speeds may have array losses around 5% centage of total output. Furthermore, smaller turbines due to effects between rows of turbines. Turbine ar-have lower maintenance costs because they don t re-rays in Class 6 or higher wind speeds will have very quire a large, expensive crane to remove the turbine if 1822low losses, especially in a single- le arrangement. repairs require and Factor also use 5-8% for array losses, higher 19for larger arrays. Using the 5% gure, the lost genera-Finally, scaling up turbine size and installing large tion associated with array losses increases the cost of numbers of turbines also imposes engineering, trans-20electricity by about cents/kWh. portation, and construction diseconomies, although these tend to be modest. Wind Speed Required to Offset Transmission Losses While engineering expertise has allowed turbines to (7 m/s at turbine)scale up to 3 MW and above, the size scaling can hit breakpoints where the cost increases become . For example, for a NEG Micon 2000/72 , the cost of increasing tower height seems to scale . The Danish Wind Industry Association that increasing tower height cost approximately $15,000 per additional 10 meters (in 2002). Adjusting 100200300400500600700for steel price increases, this would be approximately 24Transmission distance (miles)$50,000 per 10 m in 2007. If costs simply scaled linearly as this suggests, the NEG turbine could pro-duce power at a hypothetical 5 cents/kWh at the stan-Overall, transmission and array losses increase the cost dard 64 m hub height and reduce that to cents/kWh of power production. A project 500 miles distant at the outlandish height of 150 m. would cost about cents/kWh more than a local pro-ject. Higher wind speeds could lower generation costs However, this example is oversimpli ed. In tower to offset or exceed these higher transmission-related construction, the breakpoints occur in the transporta-costs. A wind speed percent higher would be tion and construction of the tower. Most turbine parts needed to offset a 500 mile trip. are delivered by atbed truck, traveling directly to the site with reasonable cost (for a MW turbine, trans-The25 second diseconomy of scale for wind farms can port is 3% of total costs - $37/kW). However, larger occur in higher infrastructure and maintenance costs. turbines can exceed standard trailer dimensions ( m While large projects save on site development and le-high by m wide, with a maximum cargo weight gal costs by spreading them over several turbines, a
Wind speed (m/s)
W6ind and Ethanol
26around 19,000 kg). If a turbine weighs over 19,000 lower levelized costs by 25% ( cents/kWh off a kg (but less than 84,000 kg) it can still be sent via baseline price of 6 cents). However, the remote loca-truck, but at 10 times the cost. One rotor for a Vestas tion of most large wind farms incurs signi cant dis-V82 turbine, for example, weighs 43,000 related to the need for increased transmis-sion - at 500 miles, the transmission costs and losses Building a tower too high also imposes signi cant ( cents/kWh) offset the size economies. costs. An 86 m turbine tower for a MW turbine has a base diameter of m, which not only exceeds stan-dard trailer dimensions ( m height) but also the trig-Ethanolger height for police escort and/or temporary utility wire disconnection ( m). Certain jurisdictions can As the ethanol industry expands, plants are growing simply refuse to allow such disruptive cargo, adding ever larger, with new dry mill plants approaching and 32expense as the truck must take a more circuitous even exceeding 100 million gallons per year (MGY). 27route. While larger plants enjoy some economies of scale in the production and distribution of ethanol, they are The turbine nacelle can also be costly to ship because modest and likely do not affect the wholesale price of of the weight. The nacelle for an 84 m rotor diameter ethanol. turbine weights the maximum (84,000 kg) for truck transport and, even with the gearbox removed, a 115 m Economies of Scale28rotor diameter nacelle would be at the limit as well. These transportation limitations account for dramatic As with many manu-Scaling Capital Costscost increases when scaling already-large turbine tow-facturing industries, ers. While an 80-meter tower costs ~$400,000 for ma-the conventional wis-Plant 40 mgy100 mgycapacityterials, transportation and installation, a 120-meter dom in ethanol pro-29tower costs nearly $ million. This may explain duction is that bigger Capital costs $$(millions)why even the larg-is more ef cient. The Crane Costs for Constructing a est turbines pro-50-turbine wind farm ($/kW) rst advantage of size Debt service $$ by GE, Ves-($/gal)is a reduction in capi-30 tas, and Suzlon tal costs per gallon. 24 Cost savings cpg18 have hub heights no over 40mgyAlthough not as scal-12 30greater than 105 as other indus-6 0 tries, where a 1% expansion of production capacity 7501500250035005000In addition to expo-only increases capital costs by %, ethanol produc-Turbine capacity (kW)nentially increasing tion does have an economy of scale. A 1% expansion transportation and in ethanol production is accompanied by a % in-33construction costs, turbines also face cost breakpoints crease in capital costs. As shown in the table, this when installation becomes more challenging. Increas-economy of scale corresponds to slightly smaller -ing tower heights create the need for substantially nancing costs per gallon of ethanol produced. A 100 larger and more expensive cranes to do installation. MGY plant will save cents per gallon (cpg) in -Crane costs for a 50-turbine wind farm increase from nance payments. One reason ethanol plants may not $9/kW for 750-kW turbines to $27/kW for hypothetical scale as well as other manufacturing types is that pro-315000-kW turbines. In both cases, the cost (spread duction costs rely heavily on the cost of the feedstock — over 10 years) is less than 1/10th cent per kWh. primarily corn. No matter how big the plant, it tends to pay the prevailing market price for corn and for energy Overall,34 larger wind turbines are indisputably more inputs (electricity and natural gas).economical than smaller ones: doubling tower height and rotor size decreases production costs by up to 80%. There are some savings on other costs however; larger-The economies are less clear regarding wind farm size. scale plants may have production economies of scale Increasing a wind farm from 10 MW to a 200 MW can from relatively lower labor and administrative costs
and Ethanol
per gallon produced. are 10 percent lower for unit trains than for mixed Average ethanol plant operating cost 3937 A 50 [MGY] etha-trains - $4,500 per car instead of $5,000.(per gallon)nol plant on average Feedstock (corn)$ employ between Unit trains generally offer scheduling and pricing ad-Electricity & natural gas$ and 40 employees vantages, but there are few terminals with the capacity Debt service$[one for every to rapidly unload a unit train — on the West Coast, there 40Capital depreciation$ gallons], is only one. Additionally, an ethanol plant has to build Labor$ a 100 its own loading track and lease or buy its own tank [MGY] plant needs cars, so a large ethanol plant will have signi cantly Enzymes$ 55 to 60 em-higher initial costs in preparing for unit train service. Maintenance$ [one for Another advantage for plants large enough to use unit Denaturant$ million trains is the avoided cost of coordinating their ship-Administrative costs$]. How-ment with other trains. Unit trains move directly from Chemicals$, labor costs are origin to destination. On the other hand, single cars Waste management$ about 2-3 per-or small groups of cars are moved less consistently Yeast$ of total plant than large groups, taking up to twice as much time to 3641Other$. Another reach their destinations. Mixed trains have to be Water$ based on engi-gathered at terminals or marshaling yards, which can 42neering estimates create shipment delays. found decreasing production costs to scale for ethanol plants up to 100 MGY, whether powered by natural On the other hand, organizations like the Renewable 37gas, coal, or biomass. Each type of plant saw a 2-3 Products Marketing Group (RPMG) provide a way for small producers to combine marketing power. Fur-cpg reduction in production costs when scaled up from 3850 MGY to 100 MGY. thermore, the Ethanol Express by BNSF helps gather ethanol production into unit trains by region, helping Once ethanol is produced, large plants may also have improve transportation logistics for smaller producers. So small producers may be narrowing the economies advantages in marketing and transportation of the product. However, there are virtually no studies of this of and ethanol marketing groups tend to even the playing eld. Overall, a 100 MGY plant saves cpg on capital costs, 2-3 cpg on production costs, and up to cpg On the transportation side, larger producers may bene-on shipping costs over a 40 MGY plant. These total economies (4-6 cpg) are signi cant to the plant owner t from price and logistical advantages of having more product to ship. With and investor, but are modest compared to the overall Ethanol Shipping Rateswholesale price 30,000-gallon tanker cars, a unit train (95 of ethanol, which Unit TrainMixed Component Related Savings: Trainhas ranged from cars) holds mil-100 MGY Ethanol Plant vs. 40 MGY PlantTrain cars9530-94lion gallons of etha-$2 to $4 per gal-lon most of the and it takes sub-Cost/car ($)$4,500$5,000stantial production to last two years. It capacity 30,00030,000is doubtful that ll it quickly. A 100 (gal) plant can ll a customers would Cost ($/gal)15 any reduction unit train about every Cost for $15 $ days. Unit train in the price at the 100 MGmillionmillion0pump if the etha-rates are less expen-sive than mixed trains, where the ethanol may be one nol industry were CapitalProductiondominated by 100 of several products or the ethanol may come from sev-Shippingeral different plants. For a BNSF railroad shipment million gallon per year plants. from SW Minnesota to Watson, CA, for example, rates
W8ind and Ethanol
DDG (of a ten pound recommended maximum) — Diseconomies of Scalemeaning a 40 MGY plant needs 180,000 head of cattle 50to use all its 126,000 tons of size seems to offer ethanol producers substantial bene ts, there are some aspects of production that suf-The signi cant number of cattle required to consume fer from diseconomies of scale. From limited local an ethanol plant s DDG means that the market for dis-markets to limited water resources, building large can tiller s grains varies greatly. Given the saturation of incur costs that smaller plants won t plants in many areas, feasibility studies for new ethanol plants are placing minimal value on this The largest ethanol plants quickly overproduce local byproduct because of the dif culty in nding willing markets for their product. In Minnesota, domestic pro-51buyers. The bigger the plant, the more buyers are duction exceeded the statewide 10% ethanol mandate needed. First, this means that more of the DWG must by 2002; currently, at least half the product is shipped be dried, since DWG can only be used in nearby mar-out of the state. For example, a unit train shipment of kets. Second, it means that the resulting DDG must be domestically produced ethanol from SW Minnesota to shipped further from the plant to reach available feed-BNSF s Minnesota terminal costs $2600 per tank car. lots. The most pressing problem resulting from out-The same shipment to Ft. Worth, TX, (900 miles) is stripping the local feed market is that DDG can clog $3350 per car; to Watson, CA (1,900 miles), it costs railroad hopper cars. While this initially meant a more 43$4500 per car. It s half as much to ship locally ( laborious transport process, since the DDG caked into cpg) as to ship long distance ( cpg to Watson). ne grain concrete with high temperatures and hu-midity, railroads eventually made ethanol plants lease The limited local market for ethanol s co-products can or buy their own railcars for DDG, adding $6/ton to the create a stumbling block for larger-scale ethanol pro-52shipping cost. Additionally, shipping DDG is more duction. The most signi cant co-product of ethanol expensive than shipping corn, since DDG is less dense. production is distiller s grains, which can be used as livestock feed. In some ethanol plants, these are left as The combination of ooding the local market and in-distiller s wet grains (DWG) and must be sold and con-creased transportation costs can create a diseconomy of sumed within a few days (three days in warm weather scale for a large ethanol plant. The box below offers a 44and six in cooler temperatures). Otherwise, the plant simulation of how two ethanol plants - 40 MGY and must apply a preservative — extending shelf life to 14 100 MGY - would operate in a regional market capable days for about $4/ton — or use natural gas to dry the of absorbing 20 million gallons of ethanol and 50,000 distiller s grains (creating DDG), for an average cost of tons of DDG (requiring over 70,000 head of cattle).45$10/ton. DDG can be stored and shipped much longer distances. A 40 MGY plant will produce approxi-46mately 126,000 tons of DDG per Drying and Shipping Costs for DDG and Ethanol in a Limited Local MarketThere are several scale limitations on the market for •Ethanol demand: 20 million gallonsDWG and DDG. First, distiller s grains are essentially •DDG demand: 50,000 tonscorn kernels stripped of their starch, leaving a much •Local ethanol shipped via rail to blending concentration of protein — a key feed ingredient. •Excess ethanol shipped via rail to Watson, CA terminalHowever, because the processing also changes the bal-•Excess DDG dried and shipped via rail to Kansas feedlotsance of amino acids and phosphorous in addition to starch and protein, distiller s grains can only provide 40 MGY100 MGY47part of the feed for livestock. Feed inclusion rates for Ethanol cpgdistillers grains are presently as high as 40 percent for 48cattle, 25 percent for swine and 5 percent for poultry, DDG cpgbut feeders typically use less to avoid adverse effects DDG cpgon feed animals. In particular, high inclusion rates can cpg49lower the grade quality of beef. On average, a cattle feedlot will provide cattle with three pounds per day of
and Ethanol
As we can see, the 100 million gallon plant has an in-Conclusioncrease in shipping and DDG drying costs that come to about cents per gallon, offsetting much of the pro-The most signi cant economies of scale in renewable duction cost savings of the larger production are in individual wind turbines, with larger towers and blades capturing signi cantly more Some ethanol plants have found alternatives to drying energy than smaller machines and reducing unit costs and shipping DDG to avoid the cost. Burning the dis-substantially (by 13% for doubling tower height and by tillers grains to fuel the plant s energy needs can dis-75% for doubling rotor diameter). There are modest place natural gas, and save on drying and shipping savings involved in moving from single to multiple since many of the same savings can be gained from a cooperative service and maintenance arrange-Water use is also a concern for larger ethanol plants. ment among many local owners. Each gallon of ethanol produced uses 5-6 gallons of water, although Minnesota ethanol producers have, on Some studies show as much as a 25% reduction in unit 53average, reduced this to gallons in 2005. For costs for electricity generation in large wind farms, but some of the early plants producing 20-40 MGY, this sending wind farm power long distances can increase meant 100-240 million gallons of water used per year. costs by 10-25%. Local generation of wind power - For one plant in Granite Falls, MN, the water demand from dispersed turbines serving a local and regional has outstripped the capacity of the local aquifer, caus-market using the existing distribution grid - can some-ing plant of cials to seek permission to get water from times be cheaper despite lower wind nearby Minnesota River and to cancel expansion 54plans. Another proposed plant near Pipestone, MN, For ethanol plants the scale advantages are also lim-was scrapped because the municipal water system ited. Increasing plant size from 40 to 100 MGY can 55lacked the capacity for the 100 million gallon facility. reduce production costs by 4-6 cents per gallon. How-The intensive water use of ethanol plants has led some ever, outstripping local markets and having to ship the states to track ethanol plant water use (Minnesota) or product long distance can increase costs by 5-6 cents to carefully study local water availability before siting per gallon. plants (Iowa). In some areas, such as Dodge City, KS, or Champaign, IL, local residents and municipalities In sum, economies of scale are real, but in most cases, have raised concerns about competing demands for modest. The most signi cant diseconomy of scale is 56water and the impact on the local water table. In gen-that bigness leads to absentee ownership, signi cantly eral, smaller plants will have a smaller impact on the reducing the bene ts to rural communities of harness-local water supply than large renewable energy. Public policymakers should decide whether the loss of those rural development bene ts is worth the small decrease in production costs.
and Ethanol
34 The economies of scale and dependence on feedstock prices will likely Referencesgovern cellulosic ethanol production, as well, though empirical evidence is 1lacking. See Morris, David. Energizing Rural America: Local Ownership of Renew-able Energy Production is the Key (ILSR, April 2007) for more detailed dis-35 Kotrba, Ron. Larger Scale, Relative Economics. Ethanol Producer cussion of the bene ts of local (May 2006). Accessed 12/5/06 at 2 Wind Speed Calculator. Danish Wind Industry Association. Accessed 6/36 Ibid20/07 at 37 Shapouri, Hosein and Paul Gallagher. USDA s 2002 Ethanol Cost-of-3 Calculations made with the Danish Wind Industry Wind Turbine Power Production Survey. (USDA, Agricultural Economic Report #841, July 2005), Calculator. Accessed 7/6/07 at 4. Costs for feedstock, DDGS, and natural gas updated with prices in Decem-ber Eggleston, Eric. Wind Energy FAQ. (American Wind Energy Association, 2/5/98). Accessed 11/9/06 at Nicola, Diego Federico. Economies of Scale in Ethanol Production Under Different Fuel Technologies. (University of Minnesota: Plan B Masters of 5 Paper, December 2005). 6 Bolinger, Mark, et al. A Comparative Analysis of Community Wind Power 39 BNSF Rate Sheet, 4/1/07. Accessed 7/9/07 at Development Options in Oregon. (Energy Trust of Oregon, July 2004), 25. 40 Ginder, Roger G. Potential Infrastructure Constraints on Ethanol Produc-7 Bolinger, et al, in Iowa. (Iowa State University, November 2006), 5. Accessed 12/5/06 8 The Economics of Wind Energy. (American Wind Energy Association, at and conversation with BNSF of cials, 12/7/ 2005). Accessed 11/9/06 at 41 Rail, Trinity. Transportation Solutions for the Ethanol Industry. Ethanol 9 Bolinger, et al, Magazine. (March 2006). Accessed 12/6/06 at 10 Conversations with Pete Sandberg at St. Olaf College (Feb. 2007) and 42David Schmidt of John Deere (May 2007) Thompson, Steven. Keep on Truckin : Ethanol Boom Creates Transporta-tion Challenges. Rural Cooperatives. (v73n5, September 2006). Accessed 11 Net metering allows customers to roll back their electric meter instead of 11/27/06 at electricity generation to the grid. This allows power producers to offset 43 BNSF Rate retail electricity purchases, a much higher rate than they would receive for selling wholesale power to a Coltrain, David. Economic Issues with Ethanol. (Kansas State Univer-12sity: Kansas Cooperative Development Center, 8/17/01), 6. Interstate Renewable Energy Council (IREC) Connecting to the Grid Project State and Utility Net-Metering Rules and Programs. (IREC, 2006). 45 Gordon, Kindra. Extending Shelf-Life, Expanded Market. (Ethanol Accessed 12/12/06 at Producer Magazine, February 2004), Factor, Tom and Tom Wind. Delivering 2,000 MW of Wind Energy to the 46 Urbanchuk, John and Jeff Kapell. Ethanol and the Local Community. Metropolitan Centers in the Midwest. (Iowa DNR, March 2002), 17.(AUS Consultants, 6/20/02), Factor and Wind Campbell, Dan. A farm-supply co-op view of ethanol. Rural Coopera-15 Factor and Wind. Distances varied from 80 to 700 milestives. (v73n5, September/October 2006). Accessed 12/5/06 at 16 Factor and Wind, 15. Calculations based on transmission losses from Os-ceola County, IA, to Milwaukee in Factor and Crooks, Anthony. Measuring the gains for distillers grains. Rural Coop-17eratives. (v73n5, September/October 2006). Accessed 12/5/06 at Slaymaker, Wes. Site Assessment. Part of Wind Prospecting presented to the Wisconsin Focus on Energy Seminar. (Windustry, 2005). Accesssed 6/5/07 at 49 VanOverbeke, Deb. Beef industry explores effects of feeding 18ethanol co-products. (Issues Update 2007, National Cattlemen s Beef Asso- Advanced Horizontal Axis Wind Turbines in Windfarms. (US Dept of ciation, March-April 2007). Accessed 6/20/07 at Energy, Of ce of Energy Ef ciency and Renewable Energy, undated), 6-19. Accessed 11/10/06 at 50 Coltrain, Factor and Wind, Gustafson, Cole. Nine Clouds on the Ethanol Horizon. (North Dakota 20State University, 11/9/06). Accessed 12/7/06 at Bolinger, et al, Crooks. Conversation with Dan Juhl, DanMar Associates, 12/13/ Merlo, Catherine. Left Behind. Rural Cooperatives. (v73n5, September/ Conversation with Dan Juhl, DanMar Associates, 12/13/ 2006). Accessed 12/5/06 at AND Keeney, 23 Danish Wind Industry Association. Accessed 12/11/06 at . Dennis and Mark Muller. Water Use by Ethanol Plants: Potential Chal- (Institute for Agriculture and Trade Policy, October 2006), 4. Ac-cessed 12/5/06 at 24 Ohio DOT interof ce communication, 7/2/07. Accessed 7/7/07 at Lien, Dennis. Water Needs May Soon Hamper Ethanol Plants. Duluth 25 Bolinger, et al, -Tribune, 6/24/06. Accessed 12/ 22/06 at ; 26Stachura, Sea. Ethanol v. Water: can both win? (Minnesota Public Radio, 9/ Smith, Kevin. WindPACT Turbine Design Scaling Studies Technical Area 18/06). Accessed 6/5/07 at 2: Turbine, Rotor, and Blade Logistics. (NREL, December 2000), p. Keeney, Dennis and Mark Muller. Water Use By Ethanol Plants: Potential Smith, p. 5-5 and . (IATP, October, 2006). Accessed 12/22/06 at 28 Smith, p. :// 2956 Brughuis, FJ. Large wind turbines: the higher the better. (Advanced Dodge City-area residents oppose plans for ethanol plant. Lawrence Tower Systems BV, 2006), -World, 11/26/06. Accessed 12/5/06 at Ethanol Production May Put Pinch on Water Resources. Associated Press 30 GE, Vestas, and Suzlon websites. Visited 7/7/ , 6/19/06. Accessed 12/5/06 at 31 Smith, p. Urbanchuk, John. Contribution of the Ethanol Industry to the Economy of the United States. (LECG LLC, 2/21/06), 7. Accessed 12/6/06 at 33 Gallagher, Paul W., et al. Plant size: Capital cost relationships in the dry mill ethanol industry. Biomass and Bioenergy. (v28, 2005, p565-571).
