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Renewable Energy Opportunities on the Farm
 

Renewable Energy Opportunities on the Farm

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Renewable Energy Opportunities on the Farm

Renewable Energy Opportunities on the Farm

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    Renewable Energy Opportunities on the Farm Renewable Energy Opportunities on the Farm Document Transcript

    • Renewable Energy ATTRA Opportunities on the Farm A Publication of ATTRA - National Sustainable Agriculture Information Service • 1-800-346-9140 • www.attra.ncat.orgBy Cathy Svejkovsky Renewable energy represents an important option for agricultural producers. This publication introducesNCAT Energy three renewable energy resources that can be attractive and economically feasible for the farm: solar,Specialist wind, and renewable fuels. This is not a technical guide for designing or installing renewable energy© 2006 NCAT systems but, instead, an overview that provides information on wind, solar, and renewable fuel technolo- gies, cost and savings, site planning, and financial incentives. A list of resources follows the narrative.Parts of this Consumer’s Guideare based on Get Your Powerfrom the Sun (DOE/GO-102003- Photos courtesy of NREL.1844); Small Wind Electric Sys-tems: A U.S. Consumer’s Guide(DOE/GO-102005-2095); andBiofuels for Your State (DOE/GO- 02001-1434), all producedby the National RenewableEnergy Laboratory (NREL), aDOE national laboratory.ContentsIntroduction ..................... 1Solar Energy ..................... 2Wind Energy..................... 9Renewable Fuelsfor Transportation ........ 14 IntroductionResources ........................ 18 Renewable energy—such as solar, wind, and biofuels—can play a key role in cre- ating a clean, reliable energy future. The benefits are many and varied, including a cleaner environment. Electricity is often produced by burning fossil fuels such as oil, coal, and natural gas. The combustion of these fuels releases a variety of pollutants into the atmosphere, such as carbon diox- would reduce CO2 emissions by 4.3 millionFunding for the development ide (CO2), sulfur dioxide (SO2), and nitro- tons per year, the equivalent of removingof this publication was provided gen oxide (NOx), which create acid rain and 850,000 cars from the road.by the USDA Risk ManagementAgency. smog. Carbon dioxide from burning fossil fuels is a significant component of green- Equally important, renewable energy tech- house gas emissions. These emissions could nologies contribute significantly to local significantly alter the world’s environment economies, creating jobs and keepingATTRA—National Sustainable and contribute to global warming. energy dollars in the local economy.Agriculture Information Ser-vice is managed by the NationalCenter for Appropriate Technol- Renewable energy, on the other hand, can This guide will introduce you to solar, wind,ogy (NCAT) and is funded under be a clean energy resource. Using renew- and renewable fuel technologies. Note thata grant from the United StatesDepartment of Agriculture’s ables to replace conventional fossil fuels it is not a technical guide for designing orRural Business- Cooperative can prevent the release of pollutants into installing renewable energy systems. ForService. Visit the NCAT Web site(www.ncat.org/agri. the atmosphere and help combat global that information, consult a professional whohtml) for more informa-tion on our sustainable warming. For example, using solar energy will have detailed technical specificationsagriculture projects. to supply a million homes with energy and other necessary information.
    • This is also not intended to To make the best use of your solar energy be a complete guide to all of system, the modules must have a clear the renewable energy oppor- “view” of the sun for most or all of the tunities available to agricul- day—unobstructed by trees, roof gables, tural producers. Among the chimneys, buildings, and other features options not covered here are of your home and the surrounding land- hydro-electric generators, scape. Some potential sites for your sys- geothermal energy, meth- tem may be bright and sunny during cer- ane digesters, and various tain times of the day, but shaded during other “biomass” energy sys- other times. Such shading may substan-Photo courtesy of NREL. tems. For more information tially reduce the amount of energy that on digesters, see the ATTRA your system will produce. publication Anaerobic Digestion of Animal Wastes: Factors to Consider. Solar Energy Throughout the United States, people areRelated ATTRA showing increased interest in capturingPublications the sun’s energy for their farm operations, homes, and businesses. These systemsBiodiesel—A Primer allow you to produce your own electricityBiodiesel: and heat water with no noise and no airThe Sustainability pollution while using a clean, renewableDimensions resource—the sun.Ethanol Opportunities Photovoltaic (PV) shingles are an attractive solarand Questions Is My Site Suitable for Solar Energy? option, since they look much like ordinary roofing shingles, but they also generate electricity. A well-designed solar energy system needs Photo courtesy of NREL.Wind-PoweredElectric Systems for clear and unobstructed access to the sun’sHomes, Farms, and rays for most or all of the day, throughoutRanches: Resources the year. Most farms and ranches have roof- In the United States, the sun is always in tops or open, sunny locations that are well-Solar-Powered the southern half of the sky but is higher suited to solar energy, and you can makeLivestock Watering an initial assessment yourself. If the loca- in the summer and lower in the win-Systems tion looks promising, your solar installer or ter. Usually, the best location for a solarFreeze Protection equipment dealer can determine whether energy system is a south-facing roof, butfor Solar-powered your home or business can effectively use a roofs that face east or west may also beLivestock Watering solar energy system. acceptable. Flat roofs also work well forSystems solar electric systems, because solar mod-Solar Greenhouses The orientation of your system (the compass ules can be mounted flat on the roof facing direction that your system faces) affects its the sky or bolted on frames tilted toward performance. the south at an optimal angle. They can also be attached directly to the roof asIn general, the sunshould be unob- “PV shingles.”structed from 9 If a rooftop can’t be used, your solar mod-a.m. to 3 p.m. forsolar collectors. ules can also be placed on the ground,PV applications either on a fixed mount or a “track-are more sensi- ing” mount that follows the sun to orienttive to minor solarobstructions than the modules. Other options includesolar thermal mounting structures that create coveredapplications. parking, or that provide shade as win-NCAT Illustration. dow awnings.Page 2 ATTRA Renewable Energy Opportunities on the Farm
    • pastures, where electricity from power lines is unavailable. PV is often much less expensive than the alternative of extend- ing power lines into these remote areas. Depending on the depth of the well (if any) and the volume of water needed, a simple pumping system can often be installed for as little as $2,500, including the cost of a pump especia l ly designed for PV power. For more information, see the ATTRA publication Solar-PoweredSolar system installed at the Heifer Ranch in Livestock Watering Systems.Perryville, Arkansas. Photo courtesy of NREL. The basic building block of PV technol- ogy is the solar “cell.” Multiple PV cells are connected to form a PV “module,”Photovoltaics the smallest PV component sold commer-What is a solar electric, or photovoltaic, sys- cially. Modules range in power output fromtem? Photovoltaic (PV) systems convert sun- about 10 watts to 300 watts. A PV systemlight directly to electricity. They work any connected or “tied” to the utility grid hastime the sun is shining, but more electric- these components:ity is produced when the sunlight is moreintense and strikes the PV modules directly • One or more PV modules, which are(as when rays of sunlight are perpendicular connected to an inverterto the PV modules). Unlike solar thermal • Inverter, which converts the sys-systems for heating water, PV does not use tem’s direct-current (DC) electricitythe sun’s heat to make electricity. Instead, to alternating current (AC)electrons freed by the interaction of sun- • Batteries (optional) to providelight with semiconductor materials in PV energy storage or backup power incells are captured in an electric current. case of a power interruption or out-PV allows you to produce electricity—with- age on the grid.out noise or air pollution—from a clean,renewable resource. A PV system neverruns out of fuel, and it won’t increase U.S.oil imports. Many PV system componentsare manufactured right here in the UnitedStates. These characteristics could make PVtechnology the U.S. energy source of choicefor the 21st century.Solar electric power comes in very handyon farms and ranches, and is often the mostcost-effective and low-maintenance solutionat locations far from the nearest utility line.PV can be used to power lighting, electricfencing, small motors, aeration fans, gate-openers, irrigation valve switches, automaticsupplement feeders. Solar electric energycan even be used to move some sprinklerirrigation systems. AC electricity is compatible with the utilityPV systems are also extremely well-suited grid. It powers our lights, appliances, com-for pumping water for livestock in remote puters, and televisions.www.attra.ncat.org ATTRA Page 3
    • Cost/Savings electric bills up front. Your monthly electric A photovoltaic (PV) system can be a substan- bills will go down, but the initial expense of tial investment. Cost-effectiveness will depend PV may be significant. By fi nancing your on system installation cost, system perfor- PV system, you can spread the cost over mance, and local electric rates. As with any many years, and rebates can also lighten investment, careful planning will help you your financial load. make the right decisions for your farm, home, The value of your PV system’s electricity or business. Before you decide to buy a PV depends on how much you pay for elec- system, there are some things to consider. tricity now and how much your utility will First, PV produces power intermittently pay you for any excess power that you gen- erate. With net metering, the PV system’s because it works only when the sun is shin- electricity is metered back to the utility, ing. This is not a problem for PV systems which offsets the electricity coming from connected to the utility grid, because any the utility. You can use the calculation box additional electricity required is automati- on this page to estimate how much electric- cally delivered to you by your utility. In the ity your PV system will produce and how case of non-grid, or stand-alone, PV sys- much that electricity will be worth. Actual tems, batteries can be purchased to store energy production from your PV system will energy for later use. Second, if you live near vary by up to 20 percent from these figures, existing power lines, PV-generated electric- depending on your geographic location, the ity is usually more expensive than conven- angle and orientation of your system, the tional utility-supplied electricity. Although quality of the components, and the quality PV now costs less than 1 percent of what it of the installation. Also, you may not get did in the 1970s, the amortized price over full retail value for excess electricity pro- the life of the system is still about 25 cents duced by your system on an annual basis, per kilowatt-hour. This is double to qua- even if your utility does offer net metering. druple what most people pay for electricity Be sure to discuss these issues with your from their utilities. A solar rebate program PV provider. Request a written estimate of and net metering can help make PV more the average annual energy production from affordable, but neither can match today’s the PV system. However, even if an esti- price for utility electricity—in most cases. mate is accurate for an average year, actual Finally, unlike the electricity you purchase electricity production will fluctuate from monthly from a utility, PV power requires year to year because of natural variations a high initial investment. This means that in weather and climate. buying a PV system is like paying years of How Much Does a PV System Cost? How much energy will a grid-connected PV system produce?* No single answer applies in every case.System Size 1-kW 2-kW 3-kW 4-kW 5-kW But solar rebates and other incentivesSeattle, WA 970 1940 2910 3880 4850 will always reduce the cost. Your priceSacramento, CA 1399 2799 4198 5597 6996 depends on a number of factors, includ-Boulder, CO 1459 2917 4376 5834 7293 ing whether your home is under construc- tion and whether PV is integrated into theMinneapolis, MN 1286 2571 3857 5142 6428 roof or mounted on top of an existing roof.Des Moines, IA 1292 2584 3876 5168 6459 The price also depends on the PV systemHouston, TX 1220 2440 3660 4879 6099 rating, manufacturer, retailer, and installer.Pittsburgh, PA 1099 2197 3296 4395 5494 The size of your system may be the mostJacksonville, FL 1286 2571 3857 5142 6428 significant factor in any measurement of costs versus benefits. A 2-kilowatt system*Estimated annual output in kWh/year (source: PV WATTS). A typical home that meets nearly all the needs of a veryuses an average of 9,400 kWh per year. Contact your utility to request a print- energy-efficient home will likely cost $8 toout of your last 12 months of electrical energy consumption. $10 per watt. At the high end, a 5-kilowattPage 4 ATTRA Renewable Energy Opportunities on the Farm
    • operations that have signifi- Area of Solar Array Needed in Square Feet cant space heating require- PV Module ments. For example, mod- Efficiency PV Capacity Rating (Watts) ern pig and poultry farms (%) raise animals in enclosed 100 250 500 1,000 2,000 4,000 10,000 buildings with carefully 4 30 75 150 300 600 1,200 3,000 controlled temperatures 8 15 38 75 150 300 600 1,500 that help maximize animal health and growth. In addi- 12 10 25 50 100 200 400 1,000 tion, these facilities often 16 8 20 40 80 160 320 800 have high ventilation needs For example, to generate 2,000 watts from a 12%-efficient system, in order to remove moisture, you need 200 square feet of roof area. toxic gases, odors, and dust. Properly designed solarsystem that completely meets the energy space-heating systems can help meet bothneeds of a large conventional home can cost of these needs.$30,000 to $40,000 installed, or $6 to $8per watt. These prices are rough estimates; Solar Greenhouse Heatingyour costs depend on your system’s configu- Solar greenhouses are designed to collectration, your equipment options, and other solar energy during sunny days and also tofactors. Your local PV dealers can give you store heat for use at night or during peri-more accurate cost information. ods when it is cloudy. They can either stand alone or be attached to houses or barns. A PV works best in an energy-efficient building. solar greenhouse may be an underground So, measures such as adding insulation and pit, a shed-type structure, or a quonset hut. sealing air leaks, as well as purchasing energy- efficient lighting, and appliances, are essential Large-scale producers use free-standing to reduce your building’s overall electricity use solar greenhouses, while attached structures before installing a PV system. are primarily used by home-scale growers. Solar greenhouses differ from conventional greenhouses in the following four ways.Net Metering Solar greenhouses:Utilities are required to offer net meteringin 40 states and the District of Columbia. In • have glazing oriented to receivenet metering, the customer is billed for the ma x imum sola r heat dur ingnet electricity purchased from the utility over the winterthe entire billing period—that is, the differ- • use heat-storing materials to retainence between the electricity coming from the solar heatpower grid and the electricity generated by • have large amounts of insulationthe PV system. The benefits of net meter- where there is little or no directing to consumers are especially significant sunlightin areas with high retail electric rates. Utili-ties also benefit because the solar-generated • use glazing material and glazingenergy often coincides with their periods of installation methods that minimize“peak” demand for electricity. heat loss • rely primarily on natural ventilationFor state-by-state net metering information, for summer coolingsee Net Metering Rules for Energy Effi-ciency at www.dsireusa.org Passive solar greenhouses are often good choices for small growers, because they areSolar Space Heating a cost-efficient way for farmers to extendSolar space-heating systems can be used the growing season. In colder climatesin livestock, dairy, and other agriculture or in areas with long periods of cloudywww.attra.ncat.org ATTRA Page 5
    • weather, solar heating may need to be sup- plemented with a gas or electric heating system to protect plants against extreme cold. Active solar greenhouses use sup- plemental energy to move solar heated air or water from storage or collection areas to other regions of the greenhouse. Use of photovoltaic heating systems for green- houses is generally not cost-effective unless you are producing high-value crops. For more information on greenhouses, see the ATTRA publication Solar Greenhouses. PV provides year round solar-assisted power to a domestic water-heating system for this residential addition in Rhode Island. Photo courtesy of NREL. Solar Crop Drying Farmers have been using the sun to dry such as a water-glycol antifreeze mixture, crops for centuries. You can take advantage in collectors most commonly mounted on of this technology simply by allowing crops a roof. The heated water is then stored to dry naturally in the field, or by spread- in a tank similar to a conventional gas or ing grain and fruit out in the sun after har- electric water tank. Then, when water is vesting. Today’s solar dryers are designed drawn from the water heater, it is replaced to provide protection from insects, rodents, with the solar-heated water from that tank. birds, as well as weather. A basic solar dyer Some systems use an electric pump to cir- consists of an enclosure or shed, screened culate the fluid through the collectors. drying trays or racks, and a solar collec- Solar water heaters can operate in any cli- tor. The design of a solar crop drying sys- tem needn’t be complicated—it can simply mate. Performance varies depending, in be a glazed box with a dark-colored inte- part, on how much solar energy is avail- rior to collect solar energy, which heats the able at the site, but also on the temper- air inside the box. The heated air is then ature of incoming water. The colder the moved through the crop material either by water, the more efficiently the system oper- natural convection or with a fan. ates. In almost all climates, you will need a conventional backup system. In fact, many For more information, see Solar Energy building codes require you to have a con- Applications for Farms and Ranches ventional water heater as the backup. at www.eere.energy.gov/consumer/your_ workplace/farms_ranches/index.cfm/ Types of Solar Water Heaters mytopic=30006 There are four basic types of solar water- heating systems available. These systems Solar Water Heating share three similarities: a glazing (typi- Water heating can account for as much as cally glass) over a dark surface to gather 25 percent of a typical family’s energy costs solar heat; one or two tanks to store hot and up to 40 percent of the energy used in water; and associated plumbing with or a typical dairy operation. A properly sized without pumps to circulate the heat-trans- solar water-heating system could cut those fer fluid from the tank to the collectors and costs in half. Hot water is also needed for back again. pen and equipment cleaning and a host of Draindown systems pump water from the other agricultural uses. hot water tank through the solar collectors, where it is heated by the sun and returned Solar Water Heater Basics to the tank. Valves automatically drain Solar water heating systems use the sun to the system when sensors detect freezing heat either water or a heat-transfer fluid, temperatures.Page 6 ATTRA Renewable Energy Opportunities on the Farm
    • Antifreeze closed-loop systems rely on an antifreeze solution to operate through cold winter months. Antifreeze solutions are sep- arated from household water by a double- walled heat exchanger. Breadbox batch systems are passive sys- tems in which the storage tank also func- tions as the collector. One or two water tanks, painted black, are placed in a well- insulated box or other enclosure that has a south wall made of clear plastic or glass and tilted at the proper angle. This allows the sun to shine directly on the tank and heat a “batch” of water. An insulated cover can provide freeze protection. Sizing YourDraindown solar water system. SystemIllustration: North Carolina Solar Center. Just as you have to choose a 30, 40-, or 50-gallon conven-Drainback systems use a separate plumb- tional water heater,ing line, fi lled with fluid, to gather the sun’s you need to deter-heat. These systems operate strictly on grav- mine the right size Breadbox batch solar water system.ity. When the temperature is near freezing, solar water heater Illustration: North Carolina Solar Center.the pump shuts off and the transfer fluid to install. Sizing adrains back into the solar storage tank. solar water heater involves determining the total collector area and the storage volume required to provide 100 percent of your building’s hot water during the summer. Solar equipment experts use worksheets or special computer programs to assist you in determining how large a system you need. Solar storage tanks are usually 50-, 60-, 80-, or 120-gallon capacity. A small (50- to 60-gallon) system is sufficient for one to three people, a medium (80-gallon) sys- tem is adequate for a three- or four-person household, and a large (120-gallon) system is appropriate for four to six people. Cost/Savings How much does a solar water-heating system cost? A solar water-heating system can cost anywhere from $1,500 to more thanDrainback solar water system. $5,000. Cost depends on a number of vari-Illustration: North Carolina Solar Center. ables, such as:www.attra.ncat.org ATTRA Page 7
    • • the presence or type of freeze lower the temperature of the hot water you protection use reduces the size and cost of your solar • size of family, business, or agricul- water heater. tural operation to be served Good first steps are installing low-flow show- • size and type of solar system erheads or flow restrictors in faucets, insu- lating your current water heater, and insu- • type of roof on which the collector is lating any hot water pipes that you can see. to be installed • building code requirements You’ll also want to make sure your site has enough available sunshine to meet your • installation costs needs efficiently and economically. Your The less expensive solar water-heating sys- local solar equipment dealer can perform a tems lack freeze protection and are applica- solar site analysis for you or show you how ble primarily for summer recreation homes. to do your own. A solar energy supplier or installer in your area can help you determine specific costs Remember: Local zoning laws or covenants may restrict where you can place your collec- for your system. tors. Check with your city and county to learn about any restrictions. How Much Will I Save? Savings from solar water heating depend on specific climate, conventional fuel costs, Be a Smart Consumer and other factors. However, a study by the Take the same care in choosing a solar Florida Solar Energy Center (FSEC) con- water heater that you would in the purchase cluded that solar water heaters could reduce of any major appliance. Your best protection water heating costs by as much as 85 per- is to consider only certified and labeled sys- cent annually, compared to the cost of an tems. One such label is put on by the Solar electric water heater. Paybacks vary widely, Rating & Certification Corporation (SRCC), but you can expect a simple payback of four a nonprofit, independent third-party organi- to eight years on a well-designed and prop- zation formed by the state energy officials, erly installed solar water heater. (Simple and consumer advocates to certify and rate payback is the length of time required to solar water heaters. recover your investment through reduced or Find out if the manufacturer offers a avoided energy costs.) warranty, and, if so, what the warranty If you are constructing a new building or covers and for how long. If the dealer you undergoing a major renovation, the econom- are buying the equipment from goes out ics are even more attractive. The cost of of business, can you get support and parts including the price of a solar water heater in from the manufacturer, or from a local plumbing contractor? a new 30-year mortgage is usually between $13 and $20 per month. The portion of Make sure that the workers who are actually the federal income tax deduction for mort- installing the system are qualified to do the gage interest attributable to the solar system work. In many states, an installer of a solar reduces that amount by about $3 to $5 per water heater must have a plumbing license. month. If your fuel savings are more than Ask the installation contractor for references $15 per month, the investment in the solar and check them. When the job is finished, water heater is profitable immediately. have the contractor walk you through the sys- tem so you are familiar with the installation. First Things First And be sure that an owner’s manual with Before investing in any solar energy system, maintenance instructions is included as part of the package. it is more cost-effective to invest in energy- efficiency measures for your building. A solar water heater is a long-term invest- Taking steps to use less hot water and to ment that will save you money and energyPage 8 ATTRA Renewable Energy Opportunities on the Farm
    • for many years. Like other renewable energy for fuel cells; $200/kW for microturbines;systems, solar water heaters minimize the no maximum specified for other technol-environmental effects of enjoying a comfort- ogies. (Subject to funding limitations.)able, modern lifestyle. In addition, they pro- Effective date: 1/1/2006. Expiration date:vide a hedge against energy price increases, 12/31/2007.help reduce our dependence on foreign oil,and are investments in everyone’s future. Renewable Energy Systems and Energy EfficiencyFinancial Incentives Improvements ProgramThe following information identifies federal www.rurdev.usda.gov/rd/farmbill9006fi nancial incentives. For more information resources.htmlon these, as well as state incentives, see the This federal grant program applies to solarDatabase of State Incentives for Renewable water heating, solar space heating, photo-Energy (DSIRE) at www.dsireusa.org. voltaics, wind, biomass, geothermal elec- tric, geothermal heat pumps, hydrogen,Residential Solar and Fuel Cell anaerobic digestion, renewable fuels, and ATax Credit fuel cells in commercial and agricultural solar waterEnacted by the Energy Policy Act of 2005 applications. Grants amount to 25 percent heater is a(Section 1335), this credit applies to solar of eligible project costs; guaranteed loans long-termwater heating, photovoltaics, and fuel cells. are 50 percent of eligible project costs investment that willIncentive amount is 30 percent, with max- (pending). Maximums are $500,000 per renewable-energy project for grants, and save you money andimums of $2,000 for photovoltaics andsolar water heating and $500 per 0.5 kW $10 million for guaranteed loans. (Sub- energy for manyfor fuel cells. (Subject to funding limita- ject to funding limitations.) Effective date: years.tions.) Effective date: 1/1/2006. Expiration 10/5/2004. Expiration date: 10/1/2007.Date: 12/31/2007. For more information onthe Energy Policy Act of 2005 and what it Wind Energymeans to you, visit the American Council More and more people are consideringfor an Energy Efficient Economy (ACEEE) wind energy as they look for affordable andat www.aceee.org/energy/legsttus.htm. For a reliable sources of electricity. Small windsummary of energy efficiency tax incentives electric systems can make a significantin the Energy Policy Act of 2005, click on contribution to our nation’s energy needs.www.aceee.org/press/Tax_incentive05.pdf. Although wind turbines large enough to provide a significant portion of the elec-Business Energy Tax Credit tricity needed by the average U.S. farm orEnacted by the Energy Policy Act of 2005 home generally require one acre of prop-(Section 1336 - 1337), this credit applies erty or more, approximately 21 million U.S. homes are built on one-acre and largerto renewables including solar water heat- sites, and 24 percent of the U.S. populationing, solar space heating, solar thermal elec- lives in rural areas. Many of these ruraltric, solar thermal process heat, geothermal areas, particularly in the western U.S.,electric, fuel cells, and solar hybrid light- also have sufficient wind speeds to makeing for commercial and industrial applica- wind an attractive alternative.tions. The industrial tax credit is currently10 percent for geothermal electric and This section will provide you with basicsolar; from January 1, 2006, until Decem- information about small wind electric sys-ber 31, 2007, the credit is 30 percent for tems to help you decide if wind energy willsolar, solar hybrid lighting, and fuel cells, work for you. Note that this discussion onlyand 10 percent for microturbines. The covers small-scale wind electric systems.geothermal credit remains at 10 percent. Two other options, not covered here, are ofMaximum incentive is $550 per 0.5 kW great importance to agricultural producers:www.attra.ncat.org ATTRA Page 9
    • First, landowners in windy locations often lower your electricity bill, help you avoid lease farmland to developers who want to the high costs of having utility power lines install large wind turbines or wind farms. extended to remote locations, prevent power These “turnkey” operations, where the interruptions, and it is non-polluting. landowner receives an annual payment, can generate an attractive income stream How Do Wind Turbines Work? while often allowing farming and livestock Wind is created by the unequal heating of grazing to continue in close proximity to the the Earth’s surface by the sun. Wind tur- wind turbines. For information about sit- bines convert the kinetic energy in wind ing large-scale wind turbines on your land, into mechanical power that runs a genera- see Electricity from the Wind: What Land- tor to produce clean electricity. Today’s tur- owners Should Know. (www.eere.energy.gov/ bines are versatile modular sources of elec- windandhydro/windpoweringamerica/docs/ tricity. Their blades are aerodynamically what_landowners_should_know.doc) designed to capture the maximum energy Second, farmers in some parts of the coun- from the wind. The wind turns the blades, try have formed cooperatives, pooling their which spin a shaft connected to a generator fi nancial resources in order to purchase that makes electricity. and operate their own large wind turbines. For more information, see Community Wind Financing, a handbook from the Environ- mental Law & Policy Center. (www.elpc.org) Wind turbines operate in harmony with farming and ranching. Photo courtesy of NREL. Is Wind Energy Practical for Me? A small wind energy system can provide you with a practical and economical source of electricity if: • your property has a good wind resource • your farm, home, or business is located on at least one acre of land in a rural areaHomeowners, ranchers, and small businesses can use wind-generated electricityto reduce their utility bills. This grid-connected system installed in Norman, Okla- • your local zoning codes or covenantshoma, reduces the owner’s utility bill by $100 per month. Photo courtesy of NREL. allow wind turbines • your average electricity bills are $150 per month or more Why Should I Choose Wind? • your property is in a remote loca- Under certain circumstances, wind energy tion that does not have easy access systems can be a cost-effective renewable to utility lines energy system. Depending on your wind • you are comfortable with long-term resource, a small wind energy system can investmentsPage 10 ATTRA Renewable Energy Opportunities on the Farm
    • Is There Enough Wind at My Site? caution should be used because local ter- rain influences and other factors may causeDoes the wind blow hard and consistently the wind speed recorded at an airport toenough at my site to make a small windturbine system economically worthwhile? be different from your particular location.That is a key question and not always eas- Airport wind data are generally measuredily answered. The wind resource can vary at heights about 20–33 feet (6–10 meters)significantly over an area of just a few miles above ground.because of local terrain influences on the Average wind speeds increase with heightwind flow. Yet, there are steps you can take and may be 15–25 percent greater at athat will go a long way towards answering typical small wind turbine hub-height ofthe above question. 80 feet (24 meters) than those measured atAs a first step, consult resources such as the airport anemometer heights. The NationalNational Wind Technology Center website at Climatic Data Center collects data from air-www.nrel.gov/wind and DOE’s Wind Power- ports in the United States and makes winding America website at www.eere.energy.gov/ data summaries available for purchase.windandhydro/windpoweringamerica to esti- Summaries of wind data from almostmate the wind resource in your region. The 1,000 U.S. airports also are included inhighest average wind speeds in the United Wind Energy Resource Atlas of the UnitedStates are generally found along seacoasts, States, available online at http://rredc.nrel.on ridgelines, and on the Great Plains; gov/wind/pubs/atlas.however, many areas have wind resources Another useful indirect measurement of thestrong enough to power a small wind tur- wind resource is the observation of an area’sbine economically. vegetation. Trees, especially conifers orAnother way to indirectly quantify the wind evergreens, can be permanently deformedresource is to obtain average wind speed by strong winds. This deformity, known asinformation from a nearby airport. However, “flagging,” has been used to estimate thewww.attra.ncat.org ATTRA Page 11
    • average wind speed for an area. For more may be able to obtain information on the information on flagging, you may want to annual output of the system and also wind obtain A Siting Handbook for Small Wind speed data if available. Energy Conversion Systems, by H. Wegley, J. Ramsdell, M. Orgill & R. Drake, Report Zoning Issues No. PNL-2521, available from National Agricultural producers generally have Technical Information Service at www.ntis. greater freedom than residential homeown- gov or 703-605-6585. ers in what they do on their own, agricul- turally-zoned land. Nonetheless, before you invest in a wind energy system, you should research potential obstacles. Some jurisdic- tions, for example, restrict the height of the structures permitted in residentially zoned areas, although variances are often obtain- able. Most zoning ordinances have a height limit of 35 feet. You can find out about the zoning restrictions in your area by calling the local building inspector, board of super- visors, or planning board. They can tell you if you will need to obtain a building permit and provide you with a list of requirements. In addition to zoning issues, your neighbors might object to a wind machine that blocks their view, or they might be concerned about noise. Most zoning and aesthetic con- cerns can be addressed by supplying objec- tive data. For example, the ambient noise level of most modern residential wind tur- bines is around 52 to 55 decibels. ThisFlagging, the effect of strong winds on area vegetation, can help determine area means that while the sound of the wind tur-wind speeds. bine can be picked out of surrounding noise if a conscious effort is made to hear it, a residential sized wind turbine is no noisier Direct monitoring by a wind resource mea- than your average refrigerator. surement system at a site provides the clearest picture of the available resource. What Size Wind Turbine Do I Need? A good overall guide on this subject is the Wind Resource Assessment Handbook, which The size of the wind turbine you need is available online at www.nrel.gov/docs/ depends on your application. Small tur- legosti/fy97/22223.pdf. Wind measure- bines range in size from 100 watts to 100 ment systems are available for costs as low kilowatts. The smaller or “micro” (100– as $600 to $1,200. This expense may or 500-watt) turbines are used in a variety of may not be hard to justify, depending on applications such as charging batteries for the exact nature of the proposed small wind recreational vehicles and sailboats. One- to turbine system. The measurement equip- 10-kW turbines can be used in applications ment must be set high enough to avoid tur- such as pumping water. Wind energy has bulence created by trees, buildings, and been used for centuries to pump water and other obstructions. The most useful read- grind grain. Although mechanical windmills ings are those taken at hub-height, the ele- still provide a sensible, low-cost option for vation at the top of the tower where the wind pumping water in low-wind areas, farmers turbine is going to be installed. If there is a and ranchers are finding that wind-electric small wind turbine system in your area, you pumping is a little more versatile and theyPage 12 ATTRA Renewable Energy Opportunities on the Farm
    • can pump twice the volume for the same Grid-Connected Systemsinitial investment. In addition, mechanical In grid-connected systems, the only addi-windmills must be placed directly above the tional equipment required is a power con-well, which may not take the best advantage ditioning unit (inverter) that makes the tur-of available wind resources. Wind-electric bine output electrically compatible withpumping systems can be placed where the the utility grid. Usually, batteries are notwind resource is the best and connected to needed. Small wind energy systems canthe pump motor with an electric cable. be connected to the electricity distributionTurbines used in residential applications system and are called grid-connected sys-can range in size from 400 watts to 100 kW tems. A grid-connected wind turbine can(100 kW for very large loads), depending on reduce your consumption of utility-suppliedthe amount of electricity you want to gener- electricity for lighting, appliances, andate. For residential applications, you should electric heat. If the turbine cannot deliverestablish an energy budget to help defi ne the amount of energy you need, the utilitythe size of turbine you will need. Because makes up the difference. When the windenergy efficiency is usually less expensive system produces more electricity than thethan energy production, making your house household requires, the excess is sent or soldmore energy-efficient fi rst will probably be to the utility. Grid-connected systems can bemore cost-effective and will reduce the size practical if the following conditions exist:of the wind turbine you need. Wind turbine • You live in an area with averagemanufacturers can help you size your sys- annual wind speed of at least 10tem based on your electricity needs and the mph (4.5 m/s)specifics of local wind patterns. • Utility-supplied electricity is expen-Wind Turbine Sizes sive in your area (about 10 to 15 Size Height Diameter cents per kilowatt-hour). 1 kW 30-100 ft. 4-8 ft. • The utility’s requirements for con- 10 kW 60-120 ft. 23-25 ft. necting your system to its grid are not prohibitively expensive. 100 kW 80-120 ft. 56-60 ft.Examples. Specific component sizes vary by manufacturer. • There are good incentives for the sale of excess electricity or for theA typical home uses approximately 9,400 purchase of wind turbines.kilowatt-hours (kWh) of electricity per year Federal regulations (specifically, the Pub-(about 780 kWh per month). Depending on lic Utility Regulatory Policies Act of 1978,the average wind speed in the area, a wind or PURPA) require utilities to connect with and purchase power from small wind energyturbine rated in the range of 5 to 10 kilo- systems. However, you should contact yourwatts (kW) would be required to make a utility before connecting to their distribu-significant contribution to this energy need. tion lines to address any power quality andThe manufacturer can provide you with theexpected annual energy output of the tur-bine as a function of annual average windspeed. The manufacturer will also provideinformation on the maximum wind speedat which the turbine is designed to operatesafely. Most turbines have automatic over-speed-governing systems to keep the rotorfrom spinning out of control in very highwinds. This information, along with yourlocal wind speed and your energy budget,will help you decide which size turbine willbest meet your electricity needs. A grid-connected wind turbine can reduce your consumption of utility-supplied electricity.www.attra.ncat.org ATTRA Page 13
    • safety concerns. Your utility can provide This federal grant program applies to solar you with a list of requirements for connect- water heating, solar space heating, photovol- ing your system to the grid. The American taics, wind, biomass, geothermal electric, Wind Energy Association (www.awea.org) geothermal heat pumps, hydrogen, anaer- is another good source for information on obic digestion, renewable fuels, and fuel utility interconnection requirements. cells in commercial and agricultural appli- cations. Grants amount to 25 percent of eli- What Do Wind Systems Cost? gible project costs; guaranteed loans are 50 A small turbine can cost anywhere from percent of eligible project costs (pending). $3,000 to $35,000 installed, depending Maximums are $500,000 per renewable- on size, application, and service agree- energy project for grants, and $10 million ments with the manufacturer. A general for guaranteed loans. (Subject to funding rule of thumb for estimating the cost of a limitations.) Effective date: 10/5/2004. residential turbine is $3,000 per kilowatt Expiration date: 2007. for systems up to 10 kW. Smaller wind systems are more costly per kilowatt of Wind Energy Production Tax Credit installed capacity. Wind energy becomes The Energy Policy Act of 2005 extends the more cost-effective as the size of the tur- tax credit for wind energy systems. The tax bine’s rotor increases. Although small tur- credit amounts to 1.9 cents-per-kilowatt- bines cost less in initial outlay, they are hour (kWh) tax credit for electricity gener- proportionally more expensive. The cost of ated with wind turbines over the fi rst ten an installed residential wind energy system years of a project’s operations. (Subject that comes with an 80-foot tower, batteries, to funding limitations.) Expiration date: and inverter, typically ranges from $13,000 12/31/2007. to $40,000 for a 3- to 10-kW wind turbine. Although wind energy systems involve a sig- nificant initial investment, they can be com- Renewable Fuels for petitive with conventional energy sources Transportation when you account for a lifetime of reduced Transportation accounts for 65 percent of or avoided utility costs. The length of the U.S. oil consumption and is the predomi- payback period—the time before the savings nant source of air pollution. However, there resulting from your system equal the cost are safe, environmentally friendly alter- of the system itself—depends on the system native fuels that can substitute for gaso- you choose, the wind resource on your site, line and diesel or be blended with them to electricity costs in your area, and how you reduce toxic air emissions. Using renewable use your wind system. fuels also reduces greenhouse gas buildup,Photo courtesy of NREL. dependence on imported oil, and trade defi- Financial Incentives cits, while supporting local agriculture and The following information identi- rural economies. fies federal financial incentives. For more information on these, What are renewable fuels? as well as state incentives, see the Renewable fuels are not petroleum-based, Database of State Incentives for so they’re cleaner burning. Renewable Renewable Energy (DSIRE) at fuels include: www.dsireusa.org. Biodiesel – a low-polluting diesel alterna- Renewable Energy Systems tive fuel made from vegetable oils, animal and Energy Efficiency fats, and even recycled cooking greases. Improvements Program Ethanol – an alcohol-based fuel derived www.rurdev.usda.gov/rd/farmbill/ from crops, usually corn, barley, and wheat. 9006resources.html Ethanol can be blended with gasoline inPage 14 ATTRA Renewable Energy Opportunities on the Farm
    • varying concentrations. E85, for example, heavy-duty AFV applications include tran-is a blend of 85 percent ethanol and 15 sit buses, airport shuttles, delivery truckspercent gasoline. and vans, school buses, refuse haulers, and street sweepers.The Energy Policy Act of 1992 (EPAct)requires state and federal government fleetsto purchase renewable fuel vehicles for three- AFV Typesquarters of their new light-duty vehicle pur- Flex-Fuel Vehicles can be fueled with gaso-chases. Additionally, renewable fuel provider line or, depending on the vehicle, with eitherfleets covered by EPAct are required to pur- methanol (M85) or ethanol (E85). The vehi-chase renewable fuel vehicles for 90 percent cles have one tank and can accept any mix-of their new vehicle purchases. Local govern- ture of gasoline and the alternative fuel.ment and private fleets are not covered by this Bi-fuel or Dual-Fuel Vehicles have tworule, but the U.S. Department of Energy has tanks—one for gasoline and one for eitherthe authority to include them at a future date. natural gas or propane, depending on theEthanol is an excellent renewable fuel (the vehicle. The vehicles can switch betweenstandard is E85, a blend of 85 percent eth- the two fuels.anol and 15 percent gasoline). Flexible-fuel Dedicated Vehicles are designed to be fueledvehicles designed to use E85 or other gaso- only with an alternative fuel. Electric vehiclesline mixtures include modified oxygen sen- are a special type of dedicated vehicle.sors and different seals in the fuel system.Because ethanol has less energy per gal- Hybrid Vehicles combine the best features oflon than gasoline, E85 vehicles also need two different energy sources, one of which islarger fuel tanks to keep the same range. electric power. Until alternative fuels reallyE85 flex-fuel vehicles qualify as alternative catch on, hybrids can be a good choice.fuel vehicles and Daimler-Chrysler, Ford,and General Motors all offer several mod- Fuelingels designed to use E85 or gasoline for the Alternative fuel stations are becomingsame price as gasoline-only models. Today, increasingly popular across the country, as92 state and alternative fuel provider fleets more consumers and agencies turn to cleanuse E85 flex-fuel vehicles to help them meet fuels. Find out where these stations aretheir EPAct requirements. using DOE’s Alternative Fuel Station Loca- tor at http://afdcmap.nrel.gov/locator.Alternative-Fuel VehiclesAlternative fuel vehicles (AFVs) can use Ethanol and Local Resourcesrenewable fuel instead of gasoline or From Corn: In the Uniteddiesel fuel. AFVs range in size and shape, States, ethanol, also known asfrom small commuter cars to large 18- grain alcohol, is made from thewheeler trucks. A number of automobile starch in kernels of field corn.manufacturers offer light-duty vehicles for (Field corn is otherwise predom-personal transportation. inantly used as animal feed; inAFVs are well-suited for fleets in certain 2005 ethanol production used“niche” markets. Taxi fleets, for example, 15 percent of the feed cornare high-mileage vehicles that drive fairly crop). Modern fuel ethanol tech-centralized routes and may benefit from nology is highly sophisticatedusing a less expensive alternative fuel such and efficient, and the processas natural gas or propane. Local delivery is similar to making alcoholicfleets with low mileage, and high-use vehi- beverages. Starch is convertedcles that frequently idle in traffic or must into sugars, the sugars areoften start and stop, may be good candi- fermented to a “beer,” and thendates for electric vehicles. Medium- and the beer is distilled to make Photo courtesy of NREL.www.attra.ncat.org ATTRA Page 15
    • pure ethanol. Of U.S. blended in one of out every eight gallons of corn ethanol production, gasoline for pollution reduction. about half is in wet-mill Ethanol made from corn is slightly more plants and half is in dry- expensive than gasoline. To encourage eth- mill plants. The former anol use, however, the federal government are typically large opera- exempts 5.3 cents per gallon of 10percent tions that produce etha- ethanol blend (53 cents per gallon of etha- nol along with a slate of nol) of the 18.3 cents per gallon federal food products such as fuel excise tax. In effect since 1979, this corn sweeteners, corn exemption makes ethanol competitive for syrup, corn oil, and glu- fuel additive use. Several states also pro-Corn is a common feedstock for ethanol, provid- ten feed. The latter are vide additional incentives. The federal sub-ing an economic boon for agricultural states. typically smaller facili- sidy, however, is more than offset by reducedPhoto courtesy of NREL. ties that produce ethanol agricultural price support payments, and as their primary product increased employment taxes for an estimated and a high-protein ani- net taxpayer savings of about $3.6 billion per mal feed known as distillers dried grains as year. The U.S. Department of Agriculture a co-product. The dry-mill plants are typi- credits the sale of corn for ethanol produc- cally located in rural communities and often tion—about 600 million bushels per year— farmer-owned, which make them an excellent with increasing corn prices by 25 to 30 cents way to develop the local economy. In 2005, per bushel. (The typical price range of field more than 80 U.S. ethanol plants produced corn is $1.80 to $2.30 per bushel.) about four billion gallons of ethanol. While ethanol accounts for about three percent of From Other Starch or Sugar: Even automotive fuel use in the United States, it is states with a small corn crop can benefitPage 16 ATTRA Renewable Energy Opportunities on the Farm
    • from building ethanol plants. Conventional reasons related to economics, air quality,ethanol technology can process any starch and health. B100 (straight biodiesel) canor sugar source. While corn certainly pre- cut carbon monoxide, hydrocarbons, partic-dominates, U.S. plants are currently mak- ulates, and other pollutant emissions in halfing ethanol from barley, milo, wheat starch, while reducing the cancer-risk contributionpotato waste, cheese whey, and brewery and of diesel by about 90 percent. Emissionbeverage waste. reductions with B20 are roughly propor- tional. Biodiesel will even reduce the smellyFrom Cellulose and Hemicellulose: oily smoke that makes it so frustrating toStarches and sugars constitute only a small get caught behind a truck, tractor, or bus.portion of plant matter. The bulk of most Since it is biodegradable, biodiesel is farplants consists of cellulose, hemicellu- more benign than petroleum-based diesellose, and lignin. Cellulose and hemicellu- fuels, should it be spilled on the ground.lose, though, are made of chains of sugars.Advanced bioethanol technology can break From Fats or Oils: Fatty acid methylthese chains down into their component sug- ester, commonly known as biodiesel, isars, and then ferment them to ethanol. This made by bonding alcohol (com-makes it possible to produce ethanol from monly methanol) to oils or fatsvirtually any biomass material. In the near- (even animal fats or used cook-term, ethanol will probably be made from ing oil). The process is relativelylow- or negative-cost opportunity feedstocks routine, but must consistentlysuch as municipal waste, wood process- achieve prescribed standardsing waste, sugarcane bagasse, rice hulls, or adopted by the American Soci-rice straw. In the mid-term, ethanol sources ety for Testing and Materials towill include agricultural and forestry resi- minimize the risk of damagingdues such as corn stover—a huge potential expensive diesel engines.source—or wood chips. From a Growing Industry:In the long-term, farmers may grow dedi- Biodiesel popularity is grow-cated energy crops, such as switchgrass or ing rapidly. According to thefast-growing trees, just for fuel production. Nat iona l Biodiesel Board,Because it requires sophisticated conversion biodiesel production reached 75technology, making ethanol from cellulosic million gallons in 2005, com-biomass is currently more expensive than pared to 25 million gallons inmaking it from corn grain—especially when 2004. As of April 2006, thereusing waste or residue feedstocks. However, are 65 commercial biodiesel Soybeans can be made into biodiesel to fuel any vehicle currently runningcellulosic feedstocks would be inexpensive, production plants in the United biodiesel with little to no conversion ofso experts expect equal or lower costs in the States, with a combined annual the vehicle. Photo courtesy of NREL.long run. Advanced bioethanol technology production capacity of 395 mil-will supplement rather than replace corn- lion gallons per year. Anothergrain ethanol by greatly expanding the poten- 50 plants are scheduled to be online by thetial feedstock supply and making ethanol end of 2007 and several plants are expand-production an option outside the Cornbelt. ing, which will have a combined annualThe U.S. Department of Energy National capacity of 713 million gallons.Biofuels Program is spearheading the effort Also, the detergent and fatty acid industries,to improve advanced bioethanol technology. which supply methyl esters to the biodieselFor more information, see the ATTRA publi- industry and can provide extra suppliescation Ethanol Opportunities and Questions. when demand grows quickly, could provide another 30-50 million gallons of capacity, ifBiodiesel—Easily Produced needed to meet demand.Many agricultural producers are taking When purchased from commercial sup-a hard look at biodiesel these days, for pliers, biodiesel is generally more expen-www.attra.ncat.org ATTRA Page 17
    • sive than diesel fuel, but B20 typically The Energy Policy Act of 2005 will provide costs only 8 to 20 cents more than reg- a federal excise tax credit for biodiesel as a ular diesel. Although usually used by tax incentive for petroleum distributors who centrally fueled fleets, biodiesel is becom- blend biodiesel with diesel fuel into both ing increasingly available at retail service on-road and off-road markets. The incen- stations across the country. tive equates to $1.00 per gallon of biodiesel made from virgin vegetable oils (like soy) For information on biodiesel distribu- and animal fats, and $0.50 per gallon for tors, suppliers, and retailers, see “Buying biodiesel made from recycled oils (subject Biodiesel” at http://nbb.org/buyingbiodiesel/ to funding appropriation.) producers_marketers/Supplier_List.pdf Newly purchased, qualified electric vehi- Farmers in some parts of the country are cles and clean-fuel vehicles (including gaso- also successfully making their own biodie- line/electric hybrids) are eligible for federal sel from waste oil, often collected from local income tax incentives: restaurants. The cost of this “home-brewed” biodiesel is often far lower than the cost of • Purchasers of hybrid and advancedB conventional diesel fuel. For more informa- lean-burn diesel vehicles can receive iodiesel is tion on making biodiesel, see the ATTRA a federal tax credit of up to $3,400. becoming publication Biodiesel – a Primer. This will be capped at 60,000 increasingly vehicles per manufacturer and willavailable at retail expire in 2014. For medium and Financial Incentives heavy hybrid trucks the tax creditservice stations The following information identifies federal will expire in 2009, and for lean-across the country. fi nancial incentives. For more information burn diesel vehicles, the tax credit on these, as well as state incentives, see the will expire in 2010. Database of State Incentives for Renewable • Electric vehicles are eligible for a Energy (DSIRE) at www.dsireusa.org. one-time tax credit of 10 percent of The Federal government exempts offers a the vehicle cost, up to $4,000 per 53 cents per gallon incentive to encourage vehicle. The credit will be reduced ethanol use. A 10-percent ethanol blend to $1,000 in 2006 and will expire fuel receives an exemption of 5.3 cents at the end of that year. For more from the federal fuel excise tax (currently information, visit www.fueleconomy. 18.3 cents per gallon). gov/feg/tax_afv.shtml.ResourcesAmerican Solar Energy Society DOE Vehicle Buyers Guidewww.ases.org www.eere.energy.gov/cleancities/vbgAmerican Wind Energy Association DOE Wind and Hydropower Technologies Programwww.awea.org www.eere.energy.gov/windandhydroDOE Biomass Program EERE Information Centerwww.eere.energy.gov/biomass www.eere.energy.gov/informationcenterDOE Clean Cities Programwww.eere.energy.gov/cleancities/transportation.html Florida Solar Energy Center www.fsec.ucf.eduDOE’s Office of Energy Efficiency and RenewableEnergy (EERE) HybridCenter.orgwww.eere.energy.gov www.hybridcenter.orgPage 18 ATTRA Renewable Energy Opportunities on the Farm
    • Interstate Renewable Energy Councilwww.irecusa.org/smallwindenergy/index.htmlNational Biodiesel Boardwww.biodiesel.orgNational Renewable Energy Laboratorywww.nrel.govNational Sustainable Agriculture InformationService/ATTRAwww.attra.ncat.orgRenewable Energy Accesswww.renewableenergyaccess.comNoteswww.attra.ncat.org ATTRA Page 19
    • Renewable Energy Opportunities on the Farm By Cathy Svejkovsky NCAT Energy Specialist © 2006 NCAT Paul Driscoll, Editor Amy Smith, Production This publication is available on the Web at: www.attra.ncat.org/attra-pub/energyopp.html or www.attra.ncat.org/attra-pub/PDF/energyopp.pdf IP304 Slot 299 Version 080107Page 20 ATTRA