August 2013

The U.S. Department of Energy established its Wind Powering America (WPA) initiative in 1999 with the goal of increasing the installed wind capacity, then around 2.5GW, to 5GW by 2005 and 10GW by 2010.  It also set goals for wind generation capacity at the state level and renewable energy consumption at the federal level of 5 percent by 2010.

In fact, by 2005 the national installed wind capacity had reached over 9GW—far surpassing the original WPA goal.  During this same time, the average generating capacity of mass produced wind turbines increased by more than 40 percent.  Wind turbines were getting taller and wind farms were growing larger.  Until this time FAA Advisory Circulars had treated wind turbines much like communication towers, requiring prescribed lighting on each structure.  Wind turbine farms represented a new type of obstruction, not a lone structure like a communication tower, and not multiple structures closely spaced together like “antenna farms,” but many tall structures spread over large distances.  The FAA’s William J. Hughes Technical Center took on the task of studying how best to mark wind turbine farms.  The study took over four years to complete and included eleven wind turbine sites in five separate states.  The result of the study, a report authored by James W. Patterson, Jr., titled “DEVELOPMENT OF OBSTRUCTION LIGHTING STANDARDS FOR WIND TURBINE FARMS” was published in November, 2005.  FAA Advisory Circular 70/7460-1K Obstruction Marking and Lighting was updated in February of 2007 and incorporates many of the recommendations of the Patterson report with the addition of Chapter 13. Marking and Lighting Wind Turbine Farms.

Marking and Lighting of Wind Turbine Farms
The following is brief summary of FAA Advisory Circular 70/7460-1K, Chapter 13, Marking and Lighting of Wind Turbine Farms.  The complete Advisory Circular is available at www.faa.gov.  Red flashing obstruction lights (FAA Type L-864) are the preferred lighting system for wind farms.  Light fixtures should be placed as high as possible on the nacelle for increased visibility.  Wind turbines around the periphery of an array of turbines should be lit.  Unlighted gaps of less than one half statue mile are allowed in many instances, however, a wind turbine located apart from the grouping of turbines should be lit.  The array of flashing obstruction lights should be synchronized to flash simultaneously.  For daytime conspicuity turbine structures painted in a bright white or light off-white color are effective.  Other colors, such as light gray or blue are less effective.

Monitoring Obstruction Lights
Section 47 of FAA Advisory Circular 70/7460-1K addresses monitoring of obstruction lights.  This brief section covers both visual and automatic monitoring. Figure 1 

Visual Monitoring
The AC states “It is extremely important to visually inspect obstruction lighting in all operating intensities at least once every 24 hours on systems without automatic monitoring.”  Since the release of 70/7460-1K in February of 2007 most wind turbine farms have used the “preferred L-864 red flashing lights.” L-864 lights have only one operating intensity so a single visual inspection every 24 hours performed when the light is operating is all that is required.  Prior to the 2007 revision of the AC, wind turbine farms may have used white lighting systems (L-865) or dual red/white lighting systems (L-864/L-865), both of which have two operating intensities.  Both of these types of lighting systems have different operating intensities for day time and night time operation.  Dual lighting systems are also commonly used on meteorological towers (MET towers).  Lighting systems with two operating intensities require visual inspection of day intensity operation and night intensity operation, requiring two inspections daily.  It can be argued that a single visual inspection where the photocell is stimulated (covered to block light or illuminated with artificial light) to force the system to change operational intensity would be an acceptable alternative, however, visual verification of night time intensities during day can prove to be difficult.  The AC also requires that a log be maintained for each lit structure in which the daily operational status of the lighting system be maintained.

•Visually inspect all L-864 red flashing obstruction lighting systems at least once every 24 hours.
• Visually inspect all L-864/L-865 obstruction lighting systems during day intensity operation and during night intensity operation.
• Maintain a log of each lit structure noting the operational status of the lighting system for each 24 hour period.  Note all operational intensities inspected.

Automatic Monitoring
While the FAA Advisory Circular does allow for visual inspection of obstruction lighting systems, the size and location of wind farms is rapidly making visual inspection impractical. The Advisory Circular addresses this in stating “In the event that a structure is not readily accessible for visual observation, a properly maintained automatic monitor should be used.”  Wind turbines are typically equipped with remote monitoring capability such as SCADA (Supervisory Control And Data Acquisition).  Wind turbine obstruction lighting systems provide dry-contact alarm points that can be easily interfaced to monitoring equipment such as SCADA for alarm notification.  All available dry contact alarms on the obstruction lighting system should be monitored.  During installation, the latency of the alarm reporting should be measured to verify that it happens quickly enough to allow reporting within the 30-minute time window.  Similar to visual monitoring, the AC similarly states that “When using remote monitoring devices, the communication status and operational status of the system should be confirmed at least once every 24 hours.” 

• Verify the communication status of the system at least once every 24 hours.
• Verify the operational status of each obstruction light at least once every 24 hours.
• Maintain a log of each lit structure noting the operational status of the lighting system for each 24 hour period.

Reporting
Section 23 of FAA AC 70/7460-1K addresses light failure notification or reporting.  The AC states “Any failure or malfunction that lasts more than thirty (30) minutes and affects a top light or a flashing obstruction light, regardless of position, should be reported immediately.”  The AC includes the basic information required for reporting an obstruction light outage, however, it refers the reader to the “telephone book” or to www.afss.com (Automated Flight Service Station) web site for information on who to contact to report outages.  Unfortunately, neither of these resources provides quick access to the contact information for reporting an outage.  A valuable resource that clearly presents this information is the FAA’s Obstruction Evaluation / Airport Airspace Analysis (OE/AAA) web site (https://oeaaa.faa.gov).  In the left side bar of this the page there is a link for “Light Outage Reporting.” The Light Outage Reporting page lists the toll free numbers for reporting, 877-487-6867, for Alaska 800-478-3576, as well as detailed information that will be required to complete the report.  This site has many other useful resources in the sidebar so it is worth spending some time exploring. When you call the toll free number, you will be connected with Lockheed Martin Flight Services. An automated system will ask you “What state are you departing from?”  You should answer will the name of the state in which you wish to report the outage. You will then be directed to Flight Service Specialist who will ask you for information regarding the outage.  The list below is an example of the minimum that should be recorded for an obstruction light outage report.  This list also contains much of the information the Flight Service Specialist may request. Figure 2 

• Your name and the name of your company or organization
• Your phone number
• Name or identification number of the structure.
• The type of Structure
• Location of structure (latitude/longitude)
• Height of structure above ground level (AGL)/above mean sea level (AMSL)
• Nearest Airport to the structure with the outage.
• A return to service date (usually assumed to be 15 days)
• Your initials (usually given using the NATO phonetic alphabet, ie. “Alpha-Zulu”)
• Flight Service Specialist initials for the outage report
• Date and time of the outage report

The Flight Service Specialist will issue a Notice to Airmen (NOTAM) describing the outage.  NOTAMs are associated with airports so you may be asked for the airport nearest the structure with the outage.  You may also be asked for the “ASN” or “ASR.” For telecommunication structures this is the Antenna Structure Registration Number, but for wind turbines and MET towers you will not have such a number. The Flight Service Station processes an average of 13,200 obstruction light outage NOTAMs each month.  Since most of these NOTAMs are issued for communication and broadcast towers it is often assumed you are reporting on a structure that is regulated by the FCC.

A NOTAM will be issued that will last 15 days after which time it will automatically be canceled.  If additional time past the 15 days is required to repair the outage, call before the NOTAM expires and request to extend the NOTAM.  Rather than let the NOTAM expire, call and cancel the NOTAM when a repair has been completed and the lighting system is functioning correctly.  Allowing NOTAMs to expire is at least considered bad housekeeping. In the world of telecommunications, FCC licensees risk fines when a NOTAM is allowed to expire.  In addition to the information listed above the date and time that the NOTAM was canceled should be recorded as well as the initials of the Flight Service Specialist who canceled the NOTAM.

• Flight Service Specialist for NOTAM cancellation
• Date and time of NOTAM cancellation

Keeping an up-to-date database of information on each structure equipped with obstruction lighting is essential to facilitating the timely and accurate reporting of light outages.

Reporting via the Internet with e-NOTAM II
At a time when everything is changing through internet connectivity one might wonder why you have to pick up a telephone and call a toll free number to report a tower light outage.  The FAA has undertaken the Federal NOTAM System (FNS) modernization initiative and it is approaching completion.  Companies providing tower light monitoring services, like my employer International Tower Lighting, LLC (www.i-nocc.com), already use FNS NOTAM Origination Service (FNS NOS) to electronically file NOTAMs, and “Sponsors” such as wind farms, broadcasters, and wireless infrastructure providers are being provided with access to e-NOTAM-II (EN-II) Web Application to request NOTAMs using a web portal.  The EN-II web site contains a new user registration link that can be used to request access.  EN-II accounts must be individual so each person who will need to file NOTAMs must register at https://notams.aim.faa.gov/en2/.

Going Further
While the FCC does not have regulatory authority over wind farms, it may be of benefit to review some of their requirements.  FCC rules in 47 CFR §17.47 require quarterly light Inspections. 
47 CFR §17.47 “The owner of any antenna structure which is registered with the Commission …. Shall inspect at intervals not to exceed 3 months all automatic or mechanical control devices, indicators, and alarm systems associated with the antenna structure lighting to insure that such apparatus is functioning properly.”

Performing and documenting quarterly light inspections would be an appropriate practice for wind farm operators to consider adopting.

Conclusion
While the majority of this article has dealt with FAA Advisory Circular 70/7560-1K requirements for reporting light outages and filing NOTAMs, a NOTAM is not a substitute for a properly functioning obstruction lighting system.  The Advisory Circular makes this point well:

“Sponsors should keep in mind that conspicuity is achieved only when all recommended lights are working. Partial equipment outages decrease the margin of safety. Any outage should be corrected as soon as possible.”

As today’s operating wind turbine assets age, owners and operators are being straddled with higher operation and maintenance costs than those experienced during the early years of operations; in many cases, more than those assumed within the pro forma. These cost increases are particularly common for wind turbine rotor blades. Even many of those operators who have signed long-term maintenance and service contracts will discover they aren’t immune to these rising costs.

Most owners and operators do not perform full-scale rotor blade inspections on the operating fleet after end-of-warranty, and are typically only carried out after the field technicians start to report increased signs of damage or when higher associated rotor blade maintenance costs dictate that the inspections be performed to get a better understanding of the conditions of the rotor blades on-site. Once the rotor blades reach this condition, on-site/on-tower repair becomes much more costly and impractical, and other options must be considered. These are commonly:

A. Allow the turbines to operate with minimal maintenance and plan for near-term re-powering of the site
B. Re-blading the wind turbines with newer blades of the same or greater length
C. Refurbishment of rotor blades
D. Some hybrid solution of b and c

Most owner/operators do not have the in-house rotor blade knowledge required to perform the comprehensive assessment of their rotor blades in order to understand their current operating condition. For this reason, many third party independent service providers (ISP’s) are brought in to perform these inspections and aid in the decision-making process for addressing issues with the rotor blades. Provided that the condition of the rotor blades is not so deteriorated that options “A” or “B” are the only feasible solutions and on-site repair is no longer an economical option, most companies prefer option “D”.

Option “D” is generally used due to the ramp-up time associated with the refurbishment process, as most spare rotor blade sets are not normally readily available on-site.  At minimum, a lag-time of 4–6 weeks can be expected from the time the rotor blades are removed from the turbine until the refurbishment is completed and the blades are ready to be re-installed. Subsequent rotor blade sets can be expected to be available at much lower lag-times. In order to minimize this downtime cost, new rotor blade sets are purchased, when possible; when not possible, older rotor blades that can be matched into a set are sought and purchased. As is most often the case, these older rotor blades require some degree of refurbishment before being installed, so in many instances these rotor blades are the first to go through the refurbishment process.

What is involved in the refurbishment process?
From the inspection findings, a detailed understanding of the wind farm rotor blades condition is known. When the discovered damage includes defects such as extensive surface coat cracking; flaking; erosion; chord-wise and span-wise cracking in the max chord and transition area; leading edge (LE) erosion; and interior defects affecting a high percentage of the rotor blade population; an off-site refurbishment plan is usually found to be the most cost effective solution—if repair is even economically feasible. In order for an owner and/or operator to proceed with this process, a number of steps need to be taken and items considered:

Step 1: Project Tender
If the work is to be performed by third party contractors, the work should be tendered to multiple potential contractors. Within the tender, a detailed scope of the work to be performed provided with the request that a fixed price for refurbishment be provided. For this reason, most owners and operators work diligently—with outside consultants when required—to establish which of the common defects require repair; and ensure that these defects are repaired under the standard scope of repair. Time and materials rates are also requested for defects requiring repair that are out of the original scope of refurbishment definition. Figure 1

Establishing, before submitting the request for tender, which rotor blade repairs need to be included as part of the fixed set refurbishment cost is critical to obtaining a higher level of cost certainty for the project. However, careful consideration must be given to which repairs are and are not critical, as this can greatly influence the overall set refurbishment cost. When replacement rotor blades are available, refurbishment costs above 40–60 percent of new rotor blades costs are generally considered as the upper limit. At a minimum, the following classes of defects require repair:

1. Interior and exterior structural defects that will have an effect on the safe operation of the rotor blade during the expected operating life
2. Lack of continuity in lightning protection system down conductor
3. Blocked drain holes
4. Missing and damaged aerodynamic elements

Additional repairs will influence the overall set refurbishment cost. However, careful consideration must also be given to the following:

1. The condition of the LE of the rotor blade commonly deteriorates. Based on an assessment of the current condition at the time of refurbishment and the local site conditions, the application of a supplementary LE protective coating is typically performed.
2. A number of interior and exterior structural defects will be discovered during inspection following operation of the rotor blades. Not all of these defects will have an effect on the safe and continued operation of the rotor blades within the rotor blade design life. Taking a conservative approach when selecting which defects require repair will increase the refurbishment cost, but will likely decrease the long-term operating costs.
3. Re-application of the final surface coat following completion of repairs is recommended for three main reasons:
a. A very patchwork surface results from the refurbishment process. This will leave the final surface condition of the rotor blade very unaesthetic.
b. Wear of the surface coating will occur as the rotor blades continue to operate.  Re-coating will ensure areas of thin coating are repaired.
 c. A refurbished surface coating will facilitate defect discovery during subsequent rotor blade inspections.

If, as is commonly requested, the contractors request access to a sample of the rotor blade population prior to responding to the request for tender, this access should be granted. It can be expected that through this inspection, the individual contractors will gain a better understanding of the rotor blade condition, and be able to provide more accurate pricing. Figure 2

It is also important that, as a requirement of responding to the tender, the contractor is able to provide demonstrated knowledge of the specific rotor blade materials and design as well as the general practices within the rotor blade repair industry. If this information cannot be provided, the contractor must be able to describe the processes that will be employed to determine this information and ensure the integrity and continued safe operating ability of the refurbished rotor blades.

Step 2: Selection of Contractor
Selection of the contractor to perform the work cannot be awarded solely on a lowest-tendered-quote basis. Careful consideration must be given during this process and individual site visits to assess the individual contractor’s capacity to perform the required work should be performed. Figure 3

Depending on the scale of the wind farm, the number of years planned for refurbishment and the capacity of the individual contractors responding the request for tender, multiple contractors may be required to complete the refurbishment project.

Step 3: Development of Standard Repair Procedures
If possible, the development of standard repair procedures should be performed prior to commencing with the rotor blade refurbishment process. Individual procedures for all of the common defects specified within the request for tender are required. This is an arduous task, and the required development of 10–20 procedures or more, is not uncommon for the full scale refurbishment process. However, as this generally set-up as a milestone event in the process, the contractor has the required encouragement to perform and complete this task. Figure 4

Accordingly, standard repair procedures contain at least the following information:

1. Specific defect condition for which the standard repair procedure applies
2. Acceptance limits for the individual defects before repair is required
3. Materials to be utilized
4. Allowable ambient environmental conditions
5. Specific and detailed instructions for performing the repair
6. Reference to quality control check and hold points
 

Step 4: Quality Assurance
A quality system designed to ensure that all inspections, repairs, and documentation are being performed as per project expectations; and where available, defined policy, is required before beginning with the refurbishment project. Once the quality system is implemented, it must be clear that at every stage of the refurbishment process a quality control plan is present and being followed. Insufficient quality control will lead to variability in the refurbished rotor blades end quality, potentially leading to increased operating costs. Periodic audits of this system should be considered as an integral part of the project due diligence. Figure 5

Step 5: Performance of Standard and Out of Scope Repairs
All defects that have a standard repair procedure must be repaired following the prescribed procedure. This ensures repair and refurbished rotor blade final condition consistency. Any and all defects that are to be repaired according to a specific standard repair procedure that are not repaired as per the standard repair procedure should be recorded as a non-conformance.

Out-of-scope repairs are for defects that require repair without a standard repair procedure. The sub-process for developing, approving, and performance of out of scope repairs must be decided prior to commencing with repair portion of the refurbishment process. As these repairs represent a cost increase to the fixed rotor blade set refurbishment cost, the scope of the repair must be clearly defined so that cost and quality assurance can be tracked and maintained.

Step 6: Documentation
As part of the delivery package for each rotor blade set, the following documentation, at minimum, should be requested and provided:
1. Interior and exterior inspection findings and defect disposition
2. Repairs performed and procedures used
3. Rotor Blade Set Balancing
a. Individual Rotor Blade Mass
1. Inclusive of mass added and location added at to balance
b. Centre of Gravity
c. Individual Rotor Blade Static Moment

Step 7: Rotor Blade Set Matching
Following the refurbishment of the rotor blades, the deviation between the individual rotor blade static moments is almost always above the allowable limit, necessitating the need for mass addition to balance the rotor blade set. Establishment of what this acceptance limit is should be performed prior to commencing with the refurbishment process. In all instances, if an OEM specified imbalance limit is available, it should be utilized. In the event no OEM specified limit is available, technical rationale for the acceptance limit to be utilized is required. Figure 6

As part of the original rotor blade design, sealed compartment(s), which are accessible from the exterior of the blade, are bonded in the rotor blade to allow for the addition of mass in order to match the individual static moments within the rotor blade set. Unfortunately, the records for the mass added to these compartments during original manufacture are not commonly available. Additionally, in many cases these compartment(s) have already been filled to max capacity. For this reason, as part of the refurbishment process, if not already defined, limits must be established for the allowable mass quantity addition and location(s) for balancing rotor blade sets. Uncontrolled mass addition to the rotor blade may lead to the development of non-design operating characteristics, affecting the safe operating condition of the turbine.

Although the rotor blades to be refurbished began as matched rotor blade sets, following refurbishment, all of these blades will not be able to be placed in their original matched sets, due to the mass addition limits defined above.  For this reason, a minimum work in progress (WIP) of approximately 3 sets is recommended. With the increased number of blades in WIP, and the common practice of some wind turbine OEM’s to have rotor blades manufactured from different rotor blade OEM’s at the same wind farm, owners and operators must be diligent in ensuring that only like operating characteristic and aerodynamic profile rotor blades are matched and whenever possible, that rotor blades are matched in sets by manufacturer and mold.

Step 8: Re-Installation on Turbine
Incoming inspection of the rotor blades prior to re-installation on the rotor hub is a due diligence check that is required. Transportation damage is commonly found, and should be repaired at this time, as the ease of access to the rotor blades and repair will provide long-term cost savings.
Additional due diligence checks such as testing of rotor mass imbalance and aerodynamic imbalance should be considered. Failing to perform these due diligence checks may lead to greater than design loading in the rotor blades and through the wind turbine drive train and structure.

Step 9: Development of Comprehensive and Thorough Long Term Maintenance Plan
Through the refurbishment process substantial costs will be incurred. In most cases, these costs could have been minimized through the development of a thorough and comprehensive long term maintenance and inspection program implemented during the original project commissioning. To avoid Einstein’s definition of insanity and repeating the original process and expecting a different end result, it is imperative that a program be developed. If an in-house model is not already available, owners and operators are encouraged to work with the contractor(s) performing the refurbishment and other industry experts to develop a cost effective program that remains sufficiently comprehensive. 

With wind power production surging to a new record last year and steady growth expected to continue, the need for reliable, effective, and community-friendly obstruction lighting has become a paramount concern for both the FAA and wind farm operators. LED technology has been used extensively in the wind power market for nearly a decade as a greener, more efficient, and reliable solution to FAA AC 70/7460-1K specified wind turbine obstruction lighting. New advances in longer-life, energy-efficient LED technology have made it the de facto standard for optimum performance, cost savings, and the lowest total cost of ownership.
 
But with new capacity on tap for construction over the next five years, and many existing wind farms due for an upgrade, operators need to know that all LED obstruction lights are not created equal. Variations in engineering design, reliability testing, product materials and even certification can mean the difference between a high-quality, long-lasting product and one that will require costly maintenance down the road.

Wind turbine beacons are unique compared to standard beacons in that each beacon light has its own internal Global Positioning System (GPS) unit and photocell. The individual wind turbines of the farm are located at substantial distances from each other, so running control wires between beacons is not practical. The GPS units in each of the beacons receive a clock signal from the orbiting satellites. The beacons use this clock signal to set the timing of their flash sequences. All beacons flash synchronously throughout the wind farm because they all use the same satellite clock signal.

The photocells in each of the beacons measure the ambient light level in order to transition the lights on and off for the day. It is important that the beacons transition on and off at about the same time each day, so a high-accuracy photocell that is stable throughout its life is important. Avoid the standard, and problematic, photoresist-type photocells and opt for a photocell that utilizes a communication-grade silicon photodiode for maximum accuracy and long life. Figure 1

If you’re thinking of an upgrade or need lighting for a new installation, here are the top ten questions you should ask any prospective LED lighting supplier to ensure you get the best product at the best value to deliver the longest life and highest return on your investment.

1. Does the product carry the required federal and local certifications?
This seems like an obvious first step, but surprisingly, there are suppliers that actually sell non-certified obstruction lighting into the wind market. In short: buyer beware. In North America, the FAA, Transport Canada, and DGAC in Mexico all have established standards that obstruction lighting must meet. In many ways, this certification provides both quality and compliance assurance—a sort of “Good Housekeeping Seal of Approval.” To reduce your risk in quality, reliability and compliance, purchase only LED systems that carry the required certifications. In fact, for operators with presence in multiple countries, it’s wise to choose a supplier with products that meet ALL certification requirements, to streamline supply chain and provide installation flexibility.

2. How well does the product perform in extreme environments?
Turbines are installed in some of the toughest conditions on earth—blistering heat, deep-freezing temperatures, and brutal winds can take a major toll on an obstruction lighting system.  To ensure maximum reliability, be sure the product you choose is rated for performance in extreme temperature ranges. The FAA standard requires third-party performance testing at a range of -40°C/F to +55°C (131°F), and reputable suppliers will provide their temperature performance testing results.

3. Does the product have battery backup capability?
Global certifications normally require 12-16 hours of battery backup capability on obstruction lighting to ensure failsafe operation in the event of a primary power outage. Look for a turnkey solution that either integrates, or is compatible with, standard battery backup systems to reduce your risk of unexpected failure, aviation safety concerns and noncompliance fines.

4. How does the product design maximize the life of the LEDs?
LEDs offer superior long life performance compared to conventional incandescent and Xenon lighting, but not all LEDs offer the same lifetime. To operate at their best, LEDs require two key design considerations: thermal management and optimal drive current. LEDs produce a fair amount of heat, and dissipating this heat efficiently is a must in order to protect the fixture components and circuitry from damage. Poor thermal management within the fixture will negatively impact the performance of the system, no matter how robust the LEDs may be.

Similarly, drive current is a major concern. In order to achieve the specified light output, some manufacturers over drive the LEDs (often using off-the-shelf power supplies not intended for demanding obstruction lighting applications), which takes a toll on the components, produces excessive heat and contributes to premature failure. To maximize your LED obstruction system investment, look for a manufacturer that incorporates state-of-the-art thermal management technology and custom-designed power supplies specifically tailored for the challenging demands of obstruction lighting. Figure 2

5. Do the LEDs come from a reputable supplier?
While there are many components in each LED flash head design, the actual LEDs are the system linchpin when it comes to maximum performance. It’s wise to purchase a system from a company that specializes in LED design and manufacturing with a long history in the LED industry. Working with a supplier that has been at the forefront of innovation, industry firsts and achieving FAA certifications for their products will ensure the investment you make will result in a quality product that delivers on the long-life performance and durability benefits of LED technology.

LED obstruction technology has seen rapid evolution over the last decade. The first FAA certified L-864 (red strobe) system became available in 2001, with the L-865 white strobe following 10 years later. Last year, the first dual high-intensity white/red L-856/L-864 strobe achieved FAA certification per AC 70/7460-1K specifications. Like most technological evolutions, each new generation of LED fixture has emerged smaller, lighter, more efficient, and longer lasting—with most products now carrying a five-year industry-standard warranty. However, it’s important to note that manufacturing processes often differ. Some suppliers are merely assemblers, putting off-the-shelf components together to build a fixture. More advanced suppliers custom-build the fixtures, including other critical components such as those used in the power supply, giving these manufacturers much greater control over the system to optimize the design for maximum performance under the harsh conditions seen on wind turbines.

6. Is the product energy efficient?
As sustainable energy advocates, wind energy producers strive to “practice what they preach,” implementing green operating practices wherever possible. It’s no doubt that LEDs provide the greenest lighting solution for this green energy industry. Consuming as little as 4W on average, the most advanced LED beacons only sip electricity to minimize energy cost and the associated CO₂ emissions. This not only reduces operating cost for overall bottom-line savings, but also amply satisfies sustainable practice initiatives for any wind operator. However, energy consumption among LED suppliers can vary. Look for the lowest-wattage lighting systems to minimize energy usage and maximize your savings.

7. Does the product offer adequate surge and lightning protection?
By their nature, wind turbines are highly susceptible to lightning strikes and other electrical discharges — and while the intense voltage levels that occur during strikes far surpasses the FAA’s requirements for surge protection, the lighting system should be able to handle all types of electrical surges. Reputable suppliers will not only satisfy the FAA standards with a certified product, but can also produce test reports to show their products’ resilience to lighting, including indirect and direct hits. Again, ask for the reports—a supplier with the credentials will be happy to provide them to you.

8. Is the flash head dome made from high-impact, UV-resistant material?
Many suppliers use acrylic material to enclose the flash head. Acrylic is susceptible to cracking from impact during installation or maintenance and hail or “shedding” of snow/ice off the rotor blades. Choose a supplier that uses high-impact UV-resistant polycarbonate material on the dome. This offers a higher IK (impact strength) rating and is more resistant to the adverse effects of UV rays. Use a lighting supplier that can apply an additional specialized “hard coat” to the dome to maximize UV protection, scratch resistance, and protection from chemical attack. This will provide about 10 years of protection out in the elements. Without this hard coating, the lens will show degradation after just a few years.  It’s also wise to make sure the product carries a minimum IP66 rating for water ingress protection, which is part of the FAA standard.
 
9. How well does the lighting system control light pollution?
The FAA specifies the minimum and maximum light intensity at zero degrees, i.e., along the horizon, for red beacons. These standards ensure beacon lights provide the proper lighting needed to alert aircraft pilots of obstructions in their flight path. However, the FAA does not specify any limits on the maximum light intensity requirements below the horizon for red beacons since this does not affect aviation safety. But, at the end of the day, complaints about disturbing flashing lights at night will go to the tower owner, not the FAA. As a result, it behooves the tower owner to evaluate the proximity of local residents to determine if light pollution may be an issue. Therefore, preventing neighbors from filing these complaints is the responsibility of the individual purchasing the obstruction lighting system. As such, it is a good idea to request light intensity distribution charts from the obstruction lighting supplier. Many suppliers will claim “community friendly” optics but some products emit more than 10 times more light pollution compared to the best products in the market.

10. Does the product have a smooth outer lens?
This might seem superficial at first (who cares what the lens looks like, right?). But, it’s actually a critical factor in the durability of the flash head. Products that incorporate optic features on the outside of the dome to direct the light, such as sharp edges and contoured shapes of Fresnel lens features, are susceptible to snow/ice buildup and accumulation of dirt and debris. On the other hand, suppliers that use internal optics design can enclose their flash head with a smooth dome that is not prone to these harsh conditions.

Future LED Road map to Meet Wind Power Needs
Down the road, a number of new challenges are on the horizon for the wind energy market. As turbines grow taller, the combined tower and blade circumference are beginning to exceed FAA medium-intensity marking requirements, obligating operators to install high-intensity lighting systems. To reduce neighborhood intrusion and energy consumption, there is also a movement toward incorporating radar technology into turbine lighting systems that would trigger the signals to come on only when aircraft are in the immediate area. In addition, the FAA is now recommending visible marking for Meteorological Tower (MET) installations used ahead of wind turbine construction to determine ideal turbine placement. While the current parameters call for orange/white paint schemes, guy wire sleeves and marker balls, these all must be maintained and replaced, causing many operators to consider whether signal lighting might be a better option. Figure 3

From a forward-looking perspective, the very nature of the LED systems design provides much more flexibility for innovation to meet these evolving needs and specifications. The combination of maintenance savings, energy efficiency and more precise optics and controller technology of LED obstruction lighting is already providing bottom-line savings and payback/ROI in as little as two years. Coupled with a customizable design that supports a road map for continued innovation, LED lighting is certain to remain the technology of choice for the wind energy market. 

In early 50 years ago, Bob Dylan sang that “you don’t need a weatherman to know which way the wind blows.” Dylan certainly wasn’t referring to the wind energy industry in 2013, but his commentary is surprisingly applicable: Surrounding every wind turbine are political factors that cannot be measured by instrumentation alone.

The things that affect whether a wind project is sited—or not—require more than sound science and excellent engineering. Reaching a favorable outcome means understanding and thriving in the local political climate by mitigating threats and influencing key decision-makers.

Power projects are inherently political, and without identifying the pitfalls on the path to permitting, consolidating support, and neutralizing opposition, even the best-planned efforts may be left twisting in the wind. What follows is an in-depth look at how to properly navigate the obstacles on your landscape so that the permitting process may go according to plan.

Gauge the Atmosphere
When it comes to a wind project, the landscape is more than just the local geography. It encompasses all of the facts on the ground, including the people and their politics. No two sites are the same, so understanding the configuration of the surrounding community—and the why and where of potentially vociferous opposition—can prevent a project from slipping off the path to approval. Indeed, when projects fall through, it is often because preliminary steps were skipped or avoidable mistakes were made.

When it comes to wind developments, scientific assessments determine the project’s internal viability. But the permitting process is not governed by science; rather, obtaining approval is more of an art. The path to success requires appropriate attention paid to external factors.

Investors in any business, whether a restaurant or shoe store, should expect a detailed market research study. That’s because good market research is predictive: It provides backers with a reliable forecast by giving due consideration to the external factors that influence the project. While wind power doesn’t operate like a retail outlet, understanding these external factors is just as valuable. This is why every wind project needs a political due diligence assessment.

Get a Good Barometer
A proper due diligence report answers critical questions that can determine a project’s likelihood of a favorable outcome. First, it examines the procedural landscape. This includes a holistic evaluation of where the battles may be fought, be they at the regional level—planning commissions, economic development committees, and zoning boards, for example—or inside local bodies like county commissions and city councils. The assessment envisions scenarios at each level of approval, paying particular heed to procedural matters. What are the guidelines for public hearings and citizen input? How does a resolution make it to the agenda? How many readings does the motion require? How many votes are needed for it to pass?

While these boards and committees hold power as a collective, they are comprised of individuals. Determining who is for or against the turbine project is only the starting point. Who are the personalities that will decide on the legislation? What motivates them and where do their allegiances lie? When are the next elections? Is the swing vote a businessman or a bureaucrat, a political neophyte or veteran decision-maker? How does this official respond to public pressure and his constituents? To learn this make-or-break information, profiles of the lawmakers in question must be created, looking to previous votes and statements on similar issues to fully elucidate their tendencies on wind energy or renewable power.

Identifying stakeholders does not stop at the policy level. The other influencers in a community—the heads of social organizations, civic groups, and local businesses—should be mapped out and their motivations and goals clearly understood. This cadre of community-minded individuals will be essential for building support for wind—or, at the very least, knowing who to keep on the sidelines. Seeking these opinion leaders prior to the permitting process can allow a wind farm developer to have key allies in hand.

Doing the appropriate due diligence is about the proverbial “ounce of prevention”—it facilitates smarter investments. As plans go off-course, they rack up high incidental costs. Imagine the damage to a developer’s bottom line stemming from unanticipated legal fees (for fending off community-based challenges), hiring experts, and even the need to make additional land acquisitions. Then multiply those expenses by the months and years of delays as the unsettled issues stumble toward resolution. These difficult scenarios can often be avoided by simply structuring the project with the most favorable political circumstances in mind. A good political due diligence assessment can save a company untold time and money by identifying the most advantageous path to permitting.

There’s No Flying Under the Radar
Determining who is negatively affected by the project—and who is most likely to transform their disapproval into vocal opposition—is often a simple matter of geography. The wind farm’s neighbors, whether they live in the shadow of the turbines or travel daily on impacted roads, are the most obvious source of hostility. They often form the core of the “Not In My Backyard” (or NIMBY) crowd that has rankled developers of projects big and small for years.

These citizens abutting the project need to be engaged from the beginning—even before feasibility is being studied—if possible. Knocking on doors in the neighborhood, listening to concerns, and identifying opponents and supporters is an important step as the permitting process begins to take shape. It may seem naive that by simply engaging residents early on, many of the potential land-mines can be defused safely—but in fact, experience shows this is the case. In-depth conversations with abutters also serve as an informal focus group, helping proponents can understand community dynamics and honing the pro-wind message accordingly. Determining which arguments—and which words—are most effective for communicating wind power’s benefits is instrumental in educating the public.

Of course, not everything will be copacetic even after the most dedicated neighbor-to-neighbor outreach. Opposing groups may be campaigning to draw attention to their cause, utilizing a combination of fliers, blog posts, letters to the editor, public meetings, rallies, and demonstrations. To address these community concerns, wind developers are known for holding town hall-style meetings in a single, centralized forum. While this approach can be well received, it opens up the possibility of a wind project’s worst nightmare—the angry mob.

A more effective approach may be a “community walk-through,” an open house-style event with small stations for engineers, developers, local officials and company employees. At a walk-through, each group of stakeholders can discuss the wind project with ordinary residents and local press. Community members will feel listened to—and the threat of a public spectacle is significantly reduced.
Meanwhile, skeptical or antagonistic public officials will have their own pulpit. It is easy for local politicians to throw in their lot with the opposition crowd; when they see an angry group of constituents, they understand the threat to re-election. More than that, however, ambitious political leaders see an emotional base of voters and seek to capitalize on their energy for the next election (and beyond). The question is, then: Who is willing to speak in favor of the wind project? Who is willing to lead the pro side and explain the benefits? Who is willing to create political cover so elected officials can support economic development and feel secure in their jobs?

This is where the dividends paid from the political due diligence assessment will be most visible. While opponents and decision-makers will be in plain view, finding a local leader to carry the torch for the project is a painstaking but important portion of the process. Often, it starts with looking at a map of the affected area and knocking on doors in the neighborhood. The invaluable nature of face-to-face interaction creates an immediate bond, and provides a launching point for developing supporters into flag-carrying leaders. This is an underrated aspect of siting a project from the grassroots: cultivating proponents early and empowering them to organize and lead.

Cause Forces to Shift
With a group of local proponents leading the way, the critical weeks and months leading up to ‘the big vote’ should be fought like a political campaign. Those managing the campaign must help their citizen leaders educate on the issue and make a lot of noise in the process. Just like a race between two candidates, local issues—like job creation, future tax revenue, funding for schools, or infrastructure improvements—must play prominent roles.

Informing and persuading should follow the tactics of a targeted media offensive. Focusing on the key players, this stage entails spreading hyper-local pro-wind messages through meetings with editorial boards, columnists, community activists, and representatives from business and trade organizations. Mobilizing pro-wind citizens and redoubling their grassroots efforts—canvassing neighborhoods on foot and by telephone—is essential.

Advertising via mail, print and broadcast media can be enormously effective at drawing attention to the campaign’s messages and should be utilized as appropriate. A site-fight also relies heavily on person-to-person communication; use of social media platforms like Facebook and Twitter, as well as blogs and YouTube videos are all vital for demonstrating broad citizen support. Similarly, a good website acts as a clearinghouse for proponents, media and information-seekers alike.

Increase the Pressure
Where the political campaign analogy diverges from an election for mayor, for example, is that ordinary citizens do not decide—and the ballot is not secret. Instead, the people that stand between a wind investor and project approval are a small group of local officials. Their vote will forever be part of the public record. Many local decision-makers understand the benefits of inviting wind energy into their community, but are faced with the pressures of elected office.

Imagine a throng of irate NIMBYs showing up to a county commission meeting, with no one there to voice support for the project. The commissioners might reasonably fear what a ‘yes’ vote could mean for their political careers. This is why a strong pro-wind citizen group is so critical—they provide decision-makers with the reassurance and political cover to permit the project.

Every community has its pressure points. If its schools are dealing with budget cuts, tax revenues from wind power generation can plug that hole. If area infrastructure is deteriorating, permitting wind turbines can provide the catalyst to fund improved roads and bridges. If crop yields are low, or families’ farms are in trouble, leases can help farmers stay afloat. If police officers and firefighters are facing layoffs, a municipal host agreement could keep those essential services properly funded.  Understanding these sensitive issues—and communicating to citizens and public officials how wind energy can solve them—is essential in shaping the outcome. No political leader would like to be known as the person who voted against restoring school budgets or keeping local farms in business.
Even at the smallest scale, the benefits of wind farms must be visible. If a little league team needs uniforms or a river needs a clean-up, donations and a civic-minded approach will help local officials and residents understand the value of siting wind in their community. The challenge is in identifying these community priorities and educating residents on their importance to the area’s ongoing debate about wind farms.

Conclusion—Always Have the Wind at Your Back
For many wind developers, it’s a terrifying thought: The difference between a project that receives approval and one that withers away can have nothing to do with investors, engineering, or environmental impact. Instead, the gatekeepers are a small group of people—sometimes well-versed in wind power, sometimes not—who need a reason to issue a permit. It starts with planning and assessment, then the painstaking work of coalition building, followed by strategic communication and public education. Properly executed, the project can sail through, applying pressure to ambivalent decision-makers and giving political cover to those officials who need it.

In other words—and with sincerest apologies to Bob Dylan—wind developers in 2013 must understand that you can’t solely use a met tower to know which way the wind blows.