Distributed Wind Turbines for Industrial and Commercial Facilities. Executive Summary

Transcription

1 Endurance Wind Power # Avenue Surrey, British Columbia V3S 3V7 T: F: endurancewindpower.com Dave Burgess 04 August 2011 White Paper Distributed Wind Turbines for Industrial and Commercial Facilities Executive Summary Distributed wind turbines are a new category of wind turbines designed to be installed behind the power meter at an industrial plant or commercial/institutional building and to generate much of the facility s energy requirements. These quiet, attractive, and productive machines make a very visible contribution to business sustainability and energy goals, and make good economic sense on the right sites. Distributed wind helps utilities to meet their renewable energy quotas and to generate power near where it is used. Governments find distributed wind more attractive than other energy alternatives and in many cases incentives are available to help fund turbine installations. Distributed wind turbines must be installed on appropriate sites where adequate wind is the first priority. Large turbine rotors and tall towers contribute directly to the power generated and are important when matching a turbine to a site. Potential turbine installations should be compared using the expected annual energy production of the machines, not the nameplate power rating. A well-supported turbine made by a reputable manufacturer with a track record of satisfied customers is also an important consideration when choosing a turbine. The economics of a wind turbine as part of a facility project can be assessed using standard methods and the return on investment (ROI) is the best metric for comparing alternatives. The potential for an increased ROI with rising energy prices and a turbine s contribution to sustainability goals and environmental branding, are factors that contribute strongly to the attractiveness of a turbine installation.

2 Table of Contents Introduction to Distributed Wind... 1 Benefits of Distributed Wind Turbines for an Industrial or Commercial Facility Project... 2 Fulfilling a Sustainable Business Strategy... 3 Meeting Green Building Requirements... 3 Fulfilling Organizational Environmental Targets... 3 Energy Security... 3 Displaying Sustainability Leadership and Branding... 3 Financial Returns... 3 Combined Benefits... 4 Distributed wind in context... 4 Feasibility of a Distributed Wind Turbine Installation... 5 The Wind Resource... 5 Power in the Wind... 5 Wind Speed Distributions... 6 Yearly Wind Energy... 8 Factors Affecting Site Wind... 9 Determining Site Wind...10 Converting Wind to Power...11 Distributed Wind Turbine Features...13 Turbine Electrical Production...13 Locating the Turbine on the Site...15 Permits and Approvals...16 Community Review...16 Grid connection Economics Capital costs Operating Cash Flows Return on Investment...18 The Right Turbine for the Right Site...18 Conclusions...19 Further Information...20 ii

3 Introduction to Distributed Wind Wind power is a common source of renewable energy. According to the American Wind Energy Association, wind provided 2.3% of American electricity in From 2007 to 2010, US wind generation capacity has doubled and provided 35% of new US generating capacity during this period. Wind is a practical, proven method of electrical generation backed by decades of experience. Today, large, utility-scale turbines provide most of the generation capacity, but smaller and more flexible distributed wind turbines are bringing on-site wind power to industrial and commercial facilities, institutions, and farms. Figure 1. Endurance E-3120 Wind Turbine BTI, Kansas Wind power can be a significant addition to new or upgraded industrial plants, or commercial and institutional facilities. These projects increasingly include components aimed at energy efficiency, sustainability, and green building. This paper explains why and when distributed wind turbines should be considered for these projects. People have become familiar with utility-scale wind power over the past few years where these projects: Have many large turbines installed in the windiest areas Sell wholesale power to utilities with complex contracts Are large and are financed by project developers Are connected directly to major electrical transmission lines and sometimes require expensive new line construction. Many people also have memories of windmills on farms, where the windmill was mainly used to pump water, but sometimes generated electricity. Today, these sites would be called off-grid applications, being located in remote 1

4 areas with scarce, high-value electric power and using batteries for storage when the wind is unavailable. Recently, a new market for medium-sized distributed wind turbines has emerged where these installations have the following characteristics: The turbine is connected to the grid but is behind the meter; a significant fraction of the power generated by the turbine is consumed on-site before passing through to the grid. This obtains retail value for much of the power, more than the wholesale price obtained by wind farms. The grid acts as a battery, supplying power when the wind is low and absorbing the extra production in strong winds. Turbines are usually installed in single units but occasionally a site has more. Turbines are located at existing facilities; not in locations specifically chosen for the strongest winds. The machines are thus optimized for efficiency in less-than-perfect winds. Although there are no firm boundaries, distributed wind turbines often have a nameplate rating of 30 kw to 200 kw, and generate 50,000 kwh to 750,000 kwh of electricity yearly. These machines are not nearly as tall as utility turbines and therefore, are acceptable on many more sites. Figure 2. Endurance E-3120 Wind Turbine Minnesota Department of Transportation Benefits of Distributed Wind Turbines for an Industrial or Commercial Facility Project Industrial plants frequently undertake capital projects for expansion, modernization, process changes, and increasingly, energy efficiency. Likewise, commercial buildings and institutions undertake projects to modernize, expand, or to control energy use. The addition of an on-site wind turbine to supply a substantial part of the electrical demand at these facilities is becoming a real alternative due to the evolution of distributed wind power. A distributed wind turbine project can provide the following benefits. 2

5 Fulfilling a Sustainable Business Strategy Many firms and organizations have adopted sustainability goals where they have recognized that energy and other resources will become scarcer and more costly in the future. It makes business sense to reduce consumption now instead of being forced into knee-jerk reactions later. On-site wind generation makes a direct contribution to these goals. Meeting Green Building Requirements Some organizations are adopting green building requirements such as Leadership in Energy and Environmental Design (LEED). Wind generation, at appropriate sites, can make a big contribution to raising the accreditation level of a facility. Fulfilling Organizational Environmental Targets Direct environmental goals, such as lower greenhouse gas emissions, have been adopted by some organizations, particularly where coal is used by utilities for electrical generation. Distributed wind power makes a big contribution in helping organizations achieve these aims. Energy Security Although distributed wind turbines require the electric grid to operate, they do provide some independence from energy supply or price increases caused by distant, unstable, or unpredictable world or national situations. A distributed wind turbine provides electricity at a fixed cost and there are no fuel expenses for the life of the turbine. Displaying Sustainability Leadership and Branding An on-site wind turbine is a very visible commitment to forward thinking and sustainable, low-impact operating policies. This is having an increased impact on customers, tenants, investors, and voters looking to support organizations that actually implement sustainability policies. Financial Returns Depending on electrical rates, the site wind resource, the turbine chosen, and the incentives available, distributed wind turbines make good economic sense. A return on investment of 5% to 33% is typical for feasible sites, without accounting for future increases in electrical rates. 3

6 Combined Benefits The benefits of distributed wind turbines need to be assessed as a package. A payback period of 8.5 years for an electric generator is not attractive; however, an investment with a 10% rate of return that contributes to business sustainability with a high public profile is appealing to many organizations. The rate of return increases with energy prices. Distributed wind in context Distributed wind generation is generally beneficial to utilities. Although utilities lose the revenue for the power that the turbine makes for the owner, many utilities need to obtain some fraction of their power from renewable sources and distributed wind generation helps them meet these obligations. Because distributed wind electricity is consumed locally, the loads on transmission lines are reduced and this delays the need for extremely expensive upgrades. As the overall demand for electricity increases, distributed wind saves utilities the cost of building both generation and transmission capacity. Distributed wind is also an industry that is attractive to governments. Distributed wind turbines are usually locally owned and revenues flow to local organizations, often in rural areas with limited economic opportunities. The distributed wind industry provides more jobs than utility wind for the same power generation and is more appealing to voters than other energy alternatives, such as building new transmission lines or nuclear plants. Despite the rapid growth of distributed wind, there remain challenges in the market. For instance, the cost of power with medium turbines is higher than with large machines. Equipment cost reductions from high-volume manufacturing are still to come and in many areas, capital or operating incentives are needed for distributed wind to make economic sense. The newness of the market means utilities don t always have streamlined connection processes and local approvals can take some time if neighbours are apprehensive. Turbine installation and support infrastructure is still developing and the market is somewhat fragmented because requirements, processes, and costs vary between regions. 4

7 Figure 3. Endurance E-3120 Wind Turbine Waste Water Treatment Facility, Perry, Idaho Feasibility of a Distributed Wind Turbine Installation This section looks at what is involved in determining if a distributed turbine is appropriate for a specific project. The professional guidance of a wind expert is suggested to confirm this initial assessment. When assessing a distributed wind turbine as part of an industrial or commercial facility project, there are several major areas to consider: 1. Wind resource available at the site 2. Converting wind to power 3. Permits and approvals needed for the turbine installation 4. Project economics The Wind Resource Power in the Wind The available wind is the dominant factor in the success of any wind turbine installation. The power in wind increases with the cube of the wind speed, that is, twice the wind speed means eight times the available power. The following graph illustrates the point. 5

8 Power in Wind (W/m 2 of rotor area) Wind Speed (m/s) Figure 4. Power in the Wind Wind Speed Distributions Wind blows at different speeds, depending on the site, weather systems, and time of day. If the probability of each wind speed on an average site were measured and graphed, it would form a Rayleigh distribution as shown below. This is considered a standard wind speed model unless specific measurements for a site have been collected. The annual average wind speed (assuming a Rayleigh distribution) is a common way to describe the strength of winds for a given site. 6

9 7.00% 6 m/s average wind speed 6.00% 5.00% Probability of Wind Blowing at Speed Shown 4.00% 3.00% 2.00% 1.00% 0.00% Wind Speed (m/s) Figure 5. Rayleigh Wind Distribution The following graph shows the difference in wind speed probabilities between sites with two different average wind speeds. 7

10 7.00% 6.00% 5.00% Probability of Wind Blowing at Speed Shown 4.00% 3.00% 6 m/s average wind speed 8 m/s average wind speed 2.00% 1.00% 0.00% Wind Speed (m/s) Figure 6. Comparing Average Wind Speeds Yearly Wind Energy For each site, the number of hours of wind at each speed can be multiplied by the energy in the wind for that speed with the following result. 8

11 [6 m/s average wind speed, Rayleigh distribution. Total site energy 2209 watt hours/m 2 of rotor] Energy Available per Year (watt hours) No energy in wind here. Wind rarely blows this hard Wind Speed (m/s) Figure 7. Yearly Wind Energy Available (by Wind Speed) The Yearly Wind Energy Available (by Wind Speed) chart is typical for many sites with reasonable wind and it shows the following: 1. There is very little energy to be collected from light winds. Therefore, there is little benefit to designing a turbine with a low cut-in speed; it would be like making a solar cell to use at night. 2. As the wind rarely blows faster than 15 m/s, there is little energy available from high winds. On most sites there is no need to have a turbine which operates in extreme winds. Factors Affecting Site Wind Regional weather patterns have the biggest effect on the average wind at a site. Hill-tops are often more exposed to the local wind while valley bottoms are normally sheltered. Sometimes valleys act as wind channels, while the lee of hills can be in a turbulent wind shadow, as can cliff-tops. Site obstructions, such as buildings or trees, create turbulent wind shadows and reduce the energy in the downstream wind. 9

12 As ground roughness slows the strong, steady upper winds, turbines on tall towers produce more power. The approximate variation of wind speed with turbine height is: (V/V 0 ) = (H/H 0 ) α where α, the wind shear exponent, varies depending on the ground cover. The standard value for α is 0.14 but it ranges from 0.4 in rough terrain (such as hedges, woodlands, and built-up areas) to 0.1 on very smooth ground like ice or the sea. A direct implication from this formula is that taller towers are more important in rough terrain. 40% Built-up areas, woodlands 20% Average terrain Change in turbine height 0% Baseline turbine height Smooth terrain - offshore or ice -20% Baseline wind speed -40% -10.0% 0.0% 10.0% Wind speed difference Figure 8. Wind Variation with Height The effect of height on wind speed must be considered when looking at different towers or when adjusting wind measurements to a different height. Determining Site Wind There are various methods to estimate winds at a potential turbine site, all with different degrees of accuracy, cost, and convenience. 10

13 Meteorological Towers A wind study with a met tower deployed for at least a year is the most accurate method to determine site wind conditions. The wind during the study period can be compared to nearby weather stations with historical records to compare the study period with long-term averages. These studies provide reliable information but they are slow, expensive, and often difficult to justify for small wind projects. Wind Maps Wind maps are available from various online sources and provide estimates of average wind speed for a specified location. These maps are based on analysis of points on a grid which is usually too coarse to account for local terrain features. Also, the effects of ground cover are not included. However, these maps are very convenient for an initial feasibility assessment. There can be occasional surprises when the site winds found after a turbine is installed prove to be very different than predicted. Wind Estimation Services Online services are available which use proprietary wind data and adjust the wind estimate based on factors like ground cover in different wind directions, site topography, and the proposed turbine height. This is convenient and provides increased confidence in the wind estimates for increased cost. However, wind surprises are still possible. Tree Deformation The Griggs Putnam index relates the deformation of trees to the long-term winds experienced at a site and is an independent confirmation of the average wind speed. Minimum Wind As a rule of thumb, it is rare to find a distributed wind project that makes economic sense with an average annual wind speed at the turbine hub of less than 5 m/s (11 mph). Converting Wind to Power A wind turbine converts wind energy to electric power. There has been extensive experimentation in turbine design, spanning a history of hundreds of years, but the key factor in judging the success of a turbine is the value of the electrical power generated compared to the cost of owning the machine. The characteristics of wind energy near the ground dictate how the turbine should be designed for maximum output at minimum cost. A large rotor area captures more wind and creates more power. Therefore, the area swept by the rotor is the primary factor in generating power in a given wind; there is no substitute. A tall tower moves the rotor into strong, smooth, upper winds and is usually the least expensive way to increase production on a given machine. Additionally, optimizing the rotor aerodynamics for the normal wind speeds at a site increases the energy collected (within the rotor diameter selected). For all except the windiest sites, turbines that operate in winds from 5 m/s to 20 m/s (11 mph to 45 mph) capture most of the available energy. Other important factors in 11

14 turbine design include safety, sound levels, reliability, and storm survival. Figure 9. Endurance S-343 Wind Turbine Turning Point Brewery, Vancouver, BC Despite the wide variety of turbines that have been built, the dominant design for on-grid generation emerged in the mid 1980s and consists of the familiar two or three bladed horizontal axis machine. No other turbine types generate a commercially significant portion of wind electricity. The horizontal axis machine generates power more economically than the other designs because of the following: They provide more rotor area for less manufacturing and maintenance costs. They can be mounted on tall towers at less cost. They have more efficient rotors over a range of wind speeds. Currently, there are some questionable wind turbine innovations riding the wave of interest in renewable energy. Signposts of some of these concepts include: Toy turbines these are machines with small rotors that generate little electricity; they are more decorative than productive. However, off-grid turbines for sailboats and remote areas are exceptions as they supply very high-value power. Short towers tall towers are required to get into the strong, productive winds that generate significant electricity. Building mounting buildings slow the wind and create severe turbulence which impairs the generation of electricity. Buildings are not built strong enough to withstand the forces of useful turbines and the turbine vibrations are unpleasant in inhabited buildings. 12

15 Vertical axis rotors while vertical axis turbines can generate real power, they have comparatively small, inefficient, and short-lived rotors. Also, they are expensive to mount and maintain on tall towers. For the equivalent cost you can get a horizontal rotor that is bigger, more efficient, and lasts longer. Vertical axis turbines have been extensively researched over many years but their limitations have precluded real commercial success. In conclusion, the effectiveness of a wind turbine is measured by its ability to generate as much electricity as possible for minimum cost and the market has been relatively effective at weeding out poor design concepts. The common public image of a wind turbine is the design that works. Distributed Wind Turbine Features A good turbine for distributed wind applications is slightly different than a utility or off-grid machine. Utility turbines are installed on wind farms in the windiest locations. Distributed wind turbines usually go on a site that was chosen for industrial or commercial purposes but still has fair wind. Distributed wind turbines should thus be optimized to work efficiently in lower winds. Other activities at the site usually involve people working or living nearby, so quiet operation and a pleasing appearance are very important qualities. A behind-the-meter turbine has the best return if it generates roughly the power consumed on-site, so distributed wind turbines are smaller than utility machines. The size and lower height of distributed wind turbines makes these machines more suitable to many sites where utility turbines are not acceptable. Turbines designed for remote or off-grid operation are often designed for harsh sites with very high winds, cold temperatures, and unstable electrical grids. These turbines may work in conjunction with complex power electronics to drive the grid and back-up batteries which store the excess energy. All of these factors drive up the cost and complication over what is needed for a standard grid-connected distributed wind turbine. The safety and reliability of wind turbines are taken for granted, but all are heavily loaded machines that operate with minimal maintenance in a harsh environment. A reputable manufacturer with a good warranty and field support organization, and a track record of satisfied customers is the best assurance of a reliable turbine that performs as promised. Turbine Electrical Production Once the site winds are known, it is possible to estimate the electric production for different turbines. Turbines are often labelled with a nominal Rated or Nameplate power which has little relation to the energy it will produce. Instead, the production should be determined from the expected site wind. Power Curve The power curve graph shows the measured turbine power compared to the short-term wind speed. Measuring a turbine power curve requires a calibrated test site and enough measurements to average out variations from turbulence. 13

16 70.0 Power Delivered to Grid (kw) Hub Height Wind Speed (m/s) Figure 10. E-3120 Wind Turbine Power Curve Annual Energy Production Annual energy production (AEP) is the key figure for comparing different turbines and sites, not rated power. To determine a turbine s AEP, multiply its power curve by each individual wind speed and duration from the site wind speed distribution. Assuming an ordinary site (using the Rayleigh wind speed distribution), this can be done for a range of average wind speeds to get an AEP graph. The AEP information is the key to estimating turbine economics at different sites and with different towers. The wind speed should be adjusted to the hub height of the turbine and, if the site wind speed distribution is known, this can be used in place of a Rayleigh distribution to obtain a more accurate site AEP. 14

17 300, , ,000 AEP (kwh) 150, ,000 50, Annual Average Hub Height Wind Speed (m/s) Figure 11. E-3120 Annual Energy Production versus Annual Average Wind Speed Turbine Size The annual energy consumption of the site is a guide for sizing a distributed wind turbine. With most utility rate structures, the best value for power is obtained if the turbine annual output is the same or less than the site energy consumption. The capacity of the site s electrical connection may also limit the turbine size. Locating the Turbine on the Site The exact location of a turbine on a site can have a major effect on its productivity, cost, and safety. The prevailing winds should have a smooth, unobstructed approach to the rotor. The rotor bottom should be at least twice the height of an obstruction for 20 times the height downstream. As well, the location of the electrical connection is important to minimize the cost and power loss of long connecting cables. Although problems are rare, turbines should not be located where the uninformed public is frequently nearby as wind turbines have heavy parts moving high in the air. Clearance of at least two rotor diameters to occupied buildings is recommended. Snow and ice can accumulate on wind turbines and this normally causes them to shut-down. Although ice usually falls near the tower, in extreme cases it can be thrown some distance from the blades. The site also requires space and access for turbine erection and service. A wind professional is the best resource to correctly site a turbine. 15

18 Figure 12. Endurance E-3120 Wind Turbine Camp Whitcomb, Hartford, Wisconsin Permits and Approvals Community Review Local authorities and neighbours can have decisive effects on allowing a wind turbine to be constructed. However, this influence is minimal for industrial sites where there is already extensive activity. The following issues may come up for consideration: Acoustics the sound effect of the turbine needs to be considered. Distributed wind turbines can be very quiet, with their sound levels masked by the wind at typical distances. Wildlife studies have shown that distributed wind turbines have virtually no effect on birds or bats. Shadow flicker large blade shadows methodically passing over sunny windows can create discomfort for the inhabitants. While distributed turbines have much smaller blades, it is best to keep shadows from strongly interfering with sunlight in frequently-used rooms. Curtains or room-lighting can help alleviate minor problems. Aviation nearby airports can impose height limits or require clearance lighting. Also, turbine blades can interfere with radar. Tower heights some areas have height limits and setback requirements. Appearance perceptions are subjective and can be affected by the familiarity of the local community with wind turbines. Three bladed machines look balanced when stopped and are more appealing than the two bladed units. Turbines are sometimes prohibited from carrying advertising. Some regions have specific policies regarding wind turbines or limit the power of communities to block turbine installations. In all cases, a wind professional can effectively sort through these issues. 16

19 Grid connection Distributed wind turbines tie-in to the site electrical supply on the customer side of the meter. Utilities are normally under some obligation to allow a turbine to be connected, assuming the technical requirements are met. For this reason, the turbine must match the site electrical system. While the capacity of the connection is usually not an issue, the utilities are interested in safeguards that prevent the turbine from energizing a grid that is being repaired. To address this issue, the machines are equipped with a relay that disconnects the turbine if grid abnormalities are detected. While the utility is also concerned about the stability of their grid, small wind turbines have little effect, particularly when most of the power is being consumed on-site. Economics The economics of a distributed wind project are often decisive in planning a project, even if other factors weigh-in on the decision. The current low price of electricity means some type of incentive is often required to make a project attractive. These incentives are given to help utilities meet renewable energy supply targets or to fulfil governmental policy objectives. In many cases, the funding for the incentive comes as a small levy on all the utility rate-payers. The need for distributed wind incentives will diminish in the future due to rising energy prices and the increased scale of the industry which will reduce the cost of turbine manufacturing, installation, and support. Distributed wind projects can be analyzed like other projects, with capital costs and operating revenues. Capital costs The capital cost of a turbine installation includes the turbine, tower, and installation costs. Capital grants offset some of these costs and often are provided as a percentage of expenses, or related to the expected turbine output. Operating Cash Flows Operating cash flow for a wind installation consists of the revenue from power generation, less the operating costs of the turbine. The electrical revenue from a turbine depends on the utility rates and policies, which vary widely. A wind specialist is the best guide to the situation. Some common concepts are: 1. Industrial and commercial customers may be billed for total energy use, a combination of energy use and peak power consumption, or time-of-day consumption. 2. Power not consumed (due to on-site generation) usually results in savings at the power rate at that moment. 3. Excess power fed back onto the grid can result in a credit ranging between zero, the wholesale power rate, the full retail rate, or a special feed-in-tariff (FIT) rate. 4. Wind power reduces peak-load billing only if the wind occurs during the peak. Similar time-of-use savings depend on when the wind blows, which is difficult to model. 5. Net-metering relates to charges for the net power consumed during the billing period. Electric meters work in either direction and net consumption is easily tracked. This is advantageous for the customer because excess 17

20 generation in high winds covers the retail-rate consumption during low wind periods. 6. There are variations in net metering, such as remote net metering, virtual net metering, or meter aggregation where the generation at one meter covers the consumption at another meter. These variations increase flexibility in deploying and owning turbines. 7. FITs are a higher payment rate for power generated with a specific technology, such as wind. FITs may cover only power exported from the site or all generation. 8. Renewable energy certificates (RECs, also called green tags) or carbon credits may also be a source of revenue if they are sold through an aggregator. In conjunction with the turbine s expected AEP, utility rates determine the revenue to be expected from a turbine. Outgoing cash flow, for instance, maintenance and insurance, are handled similarly as in any other capital project. Return on Investment As with all capital projects, the return-on-investment (ROI) is the best metric for comparing a turbine installation with other uses of cash. Comparing payback periods over-emphasizes the risk and ignores the long-term benefits of a project. A payback period of 8.5 years for a wind turbine doesn t sound attractive but an equivalent 10% rate of return (which increases with energy prices) coupled to a very public environmental dividend and branding opportunity is appealing to many more customers. The ROI for distributed turbines in acceptable sites ranges from 5% to 33%, depending on the wind speed, incentives, electric rates, productivity of the equipment chosen, and installation variables. The Right Turbine for the Right Site When the factors of available wind, turbine capabilities, compatibility with utilities and the community, and project economics are considered, the right turbine for the site can be determined. Different factors favour different turbines, towers, installation locations, and financial models there is no universal solution. It is surprising how often wind turbines are proposed or even installed on sites with little wind, or other serious problems. Wind and energy are both intangible and once seeded with the idea of wind power, some clients become very enthusiastic despite the realities of their situation. Often the desire to make a public commitment to environmental issues dominates all other considerations. Wind turbines should be installed only on productive, safe sites. Sites with low wind will have turbines that are frequently stationary, which raises public doubts about the effectiveness of wind power. Poor revenue and non economical sites can lead to the neglect of turbine maintenance and create an eyesore that lasts for years. Poorly-performing turbines also damage the reputation of the installer and designer, who look to previous installations for references. Inappropriate installations should not be pursued despite short-term customer pressures. 18

21 Figure 13. Endurance E-3120 Wind Turbine Orion Energy Systems, Manitowoc, Wisconsin Conclusions Distributed wind turbines could make a valuable contribution to many industrial or commercial facility projects, particularly for organizations with business sustainability, environmental, or energy goals. As well, distributed wind turbines provide a visible public signpost of commitment to these strategies. In addition to this, distributed wind turbines can provide a good return on investment, with an upside potential if energy prices rise or supplies are constrained. Distributed wind turbines need to be installed on appropriate sites to be successful. The most important factor for a good site is adequate wind. The local utility rate structure and incentives available are also important considerations. As part of planning the project, the other site details need to be reviewed and approval obtained from the local community. The correct turbine and tower need to be selected for a solution that is productive, attractive, quiet, and well supported. Distributed wind is a growing segment of the renewable energy industry and it provides benefits for businesses, utilities, and communities. This industry will contribute to the growing need for renewable energy in the future. 19

22 Further Information American Wind Energy Association. Oriented more to the utility wind industry. Retrieved August 4, 2011, from Canadian Wind Energy Association. Oriented more to the utility wind industry. Retrieved August 4, 2011, from Danish Wind Energy Association. This site has an excellent wiki with a wide range of turbine information. Retrieved August 4, 2011, from Database for State Incentives for Renewables and Efficiency: Retrieved August 4, 2011, from Distributed Wind Energy Association. Specifically oriented to distributed wind turbines. Retrieved August 4, 2011, from Gipe, Paul. (2004). Wind Power. Chelsea Green Publishing Company. ISBN This book is considered the authoritative reference of small to medium wind turbine selection and installation. About Endurance Wind Power Endurance Wind Power is a manufacturer of advanced small wind turbines from 5 to 50 kw in size, designed specifically for distributed wind power applications. Their line of modern, induction-based wind turbines brings efficient, reliable, safe and quiet, renewable energy within reach of homeowners, farmers, businesses and institutions across North America, the United Kingdom, and an expanding global market. Endurance Wind Power, Inc All rights reserved. All other brands or products are trademarks or registered trademarks of their respective holders and should be treated as such. The information contained in this White Paper is not for general publication or distribution, directly or indirectly, and is intended only for use of the individual or entity sent to. Any unauthorized review, use, disclosure, or distribution is prohibited. The technical data is subject to change without notice. 20