Page 4 April 2009 UW College of Agriculture

Considerations for small wind systems in Wyoming

By Lindsay Taylor one acre, siting a in by all lenders. Wind energy is a familiar a place with unobstructed wind Example of wind All of these economic con- technology to many Wyoming flow may be difficult. Typically, a turbine sizing: siderations will vary by situation residents. 100- to 160-foot tower is needed but are factors in the feasibility There was a time wind was for unobstructed and maximum of small wind use on the ranch 750 kW-h average the most common form of potential wind access. Placing a or residence. There are several turbine too low or behind trees monthly use Web calculators available to help energy used at the farmstead. × 12 months = and buildings is like putting solar determine payback periods for were used to pump 9,000 kW-h annual use panels in the shade. these projects. The U.S. Depart- water and run the first of many w Sizing of the system is the (9,000 kW-h) ÷ ment of Energy’s - electrical appliances to come main factor in determining 8,760 h/year) = 1.03 kW ing America Web site has a free into a home. upfront costs. For most grid- payback calculator program While today’s technologies tied systems – those producing (1.03 kW) ÷ available on the “Small Wind are more efficient and utilize .20 = electricity that flows onto the Economic Model” link, which electrical rather than mechanical 5.14 power grid – having a turbine can be found at www.windpow- energy, the concept is very much that produces more electricity In this case a 5-kW eringamerica.gov/small_wind. the same and can still be used than is needed by the farm or turbine would asp. on a farm or at a rural residence residence is not cost effective. be a sufficient-sized use and to offset our growing electricity To determine individual needs, tower development is a popular topic needs and rising costs. the number of kW-h used in one in news and government policy. Residential wind energy, year is divided by the number of Whether people are interested termed “small wind,” is wind hours in a year, 8,760, and then in it for economics, energy electricity generation of less than comparable if the upfront costs ity prices are generally quite low divided by the capacity factor for can be recouped in electricity and therefore often not worth the independence, environmental 10 kilowatts (kW). The average the site. The number of kW-h can concerns, or other reasons, there American home uses about 20 savings before the end of the upfront cost of installing a small be found on old electricity bills. useable life of the equipment. wind system. A good rule of are many benefits to considering kilowatt hours (kW-h) per day. The capacity factor of the site de- renewable energy sources for Residential scale wind develop- The four factors that will deter- thumb for this is if someone has pends on the wind resource. This mine this are the wind resource, a greater than $150 per month ranch or residential use. In many ment is much different than the number is the percentage of time average monthly electricity average cost of electricity. cases, it may be worthwhile for commercial wind development the wind blows hard enough costs, state and federal policies, landowners to at least consider projects seen throughout the State, Federal Policies for the turbine to produce at and financing. utilizing the wind resource that state. Turbines are much smaller, maximum capacity. For most State and federal policies just might be Wyoming’s next as they are typically generating small applications, this number Wind Resource are a consideration because they source of energy generation. electricity for only one home is between 15 and 25 percent. Most of Wyoming has a high may decrease the upfront cost Lindsay Taylor is a University of rather than a region and they are Currently, small wind turbines enough average annual wind of the project and can dictate Wyoming Cooperative Extension much less invasive on both land cost anywhere from $2,000 to speed to consider wind genera- the availability of . Service area educator in and scenery. tion. A general rule of thumb is Federal and state governments $7,000 per installed kW. northeast Wyoming. She can be Residential-sized turbines greater than 10 mph. For a better have several grant programs, Important Considerations reached at (307) 682-7281 can be used to supplement exist- look at the map of Wyoming’s rebates, and other incentives or [email protected]. ing electricity use or in a hybrid The two most important wind resource shown below, to aide in installing renewable system designed to power a considerations are the wind re- please see www.windpowerin- energy projects. home or farm without tying into source and economic feasibility. gamerica.gov/wind_maps.asp. A listing of Wyoming-specif- the existing power grid. Each of These two factors are directly Without actual data collection ic incentives can be found at the these uses has its own benefits, related because the better the from a specific site, determin- “Database of State Incentives for drawbacks, and considerations. wind resource the more electric- ing the true wind resource is Renewables and Efficiency” at ity can be generated by the wind difficult; however, this map is Small Wind Turbines turbine and the more quickly the a way to get a fair idea of a A small wind turbine tied turbine can return its upfront site’s potential. If a site-specific http://www. into the utility power grid can costs to the owner. study is desired, the Wyoming dsireusa.org/. Net metering is be practical for people who live There are many advantages Business Council offers an an- a mandated policy in Wyoming. in a rural residential location of using wind power to supple- emometer loan program. An This means utilities are required near an existing power line. To ment electricity needs, ranging anemometer placed on site for to net meter their customers be a feasible option, the basic from self-sufficiency to envi- a year will provide specific wind producing small amounts of requirements are more than ronmental benefit to providing speed data that can be useful in renewable energies. Therefore, one acre of land in a place with energy with little or no water a decision to purchase or site a electric bills would reflect only no restrictions on tall towers, requirement; however, most peo- wind turbine. The annual energy the difference between what is a known amount of electricity ple will not embrace the technol- output (AEO) of a wind turbine is used by the customer and what is used, substantial wind, and eco- ogy unless it is cost competitive equal to 0.01328 (a constant) × produced. The specific terms of nomic feasibility. If the property with existing sources of power. rotor diameter2 × wind speed3 these agreements vary by utility to be powered sits on less than Wind energy is economically so small increases in wind speed and are on file with the Wyoming translate to big gains in energy Public Service Commission. output. For more information on Financing the Wyoming Anemometer Loan The final consideration in Program, contact Tom Fuller at economic feasibility is financing (307) 777-2804. options. If a turbine is financed, Monthly Electricity Costs the interest will be a cost that Average monthly electricity needs to be considered in the costs are another important con- payback period. Grants and sideration and one that makes cost-share programs are pos- residential wind turbines less sible ways to decrease the feasible in Wyoming than the amount of a project financed. wind resource would predict. Financing a wind turbine The more money spent on elec- as a part of new home tricity, the more quickly on-site construction can greatly production of electricity will pay decrease the payback for itself. In Wyoming, electric- period but is not allowed