Appendix H Evans Associates Report on the Effects upon RF Facilities due to the construction of the PdV Wind Energy Project

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1 Appendix H Evans Associates Report on the Effects upon RF Facilities due to the construction of the PdV Wind Energy Project

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3 ENGINEERING REPORT CONCERNING THE EFFECTS UPON FCC LICENSED RF FACILITIES DUE TO THE CONSTRUCTION OF A WIND TURBINE FARM At Kern County, California PPM Energy Revised: March 19, 2007 By: B. Benjamin Evans, P.E. Evans Associates 210 South Main Street Thiensville, WI PHONE FAX Page 3

4 ENGINEERING REPORT CONCERNING THE EFFECTS UPON FCC LICENSED RF FACILITIES DUE TO THE CONSTRUCTION OF A WIND TURBINE FARM At Kern County, California PPM Energy I. INTRODUCTION This engineering report describes the results of a study and analysis to determine if certain FCClicensed microwave and two-way transmitting facilities would be adversely impacted as a result of the construction of the PdV wind turbine farm in Kern County, California. This document describes impact zones, and any necessary mitigation procedures, along with recommendations concerning individual wind turbine locations. All illustrations, calculations and conclusions contained in this document are subject to on-site verification 1. Frequently, wind turbines located on land parcels near RF facilities or receivers can cause an impact that affects spectrum users. The purpose of this study is to facilitate the siting of turbines to avoid unacceptable impact to FCC licensed RF facilities. The wind turbines to be used will have a rotor diameter of 77 meters. The total height will not exceed 122 meters above ground level to the tip of one blade at the 12:00 position. The windfarm project occupies an area about 13 miles south of the city of Tehachapi in eastern Kern County (see Figure 1 attached). Using industry standard procedures and FCC databases, a search was conducted to identify existing and proposed microwave paths crossing the subject property. In addition, public safety and other two-way RF facilities in or near the turbine area were searched. These searches revealed three proposed microwave paths that have been applied for at the FCC, all apparently connected with this project (shown in attached Figures 1 and 2) that would impact the turbine property. No existing microwave paths were found to impact the area. Also, no land mobile or public safety antenna sites were found to be significantly impacted by the wind project. 1 The databases used in creating the attached tables and maps are generally accurate, but anomalies have been known to occur. An on-site verification survey is suggested as part of the pre-construction surveys. PdV Engineering Report All Rights Reserved 2007 Page 4

5 The following analysis examines in detail the pertinent FCC licensed services in the area for significant adverse impact. This analysis assumes that all licensed services have been designed and constructed according to FCC requirements and good engineering practice. Pertinent data has been taken from FCC databases. Important Note: Microwave path and fixed station studies are based upon third party and FCC databases that normally exhibit a high degree of accuracy and reliability; however, database errors do exist that may lead to incomplete results. Before the turbine layout is finalized, a land surveyor should visit the transmit and receive sites of the RF facilities that might be affected, in order to confirm their locations through actual survey, and to determine if antennas for the licensed facilities are actually at the sites and if so, if they appear to be in operation. Each of the RF analyses is described separately in the sections that follow. II. ANALYSIS OF MICROWAVE LINKS An extensive analysis was undertaken to determine the likely effect of the new wind turbine farm upon the existing and proposed microwave paths, consisting of a Fresnel x/y axis study. The microwave path is overlaid on the USGS topographic base maps, attached, and are also available as overlays for the GeoPlanner program files. In the Comsearch study, Worse Case Fresnel Zones (WCFZ) were calculated for each microwave path. The mid-point of a microwave path is the location where the widest (or worst case) Fresnel zone occurs. Possible geographic coordinate errors must be added to the Fresnel zone clearance numbers 2. The radius R of the Worst Case Fresnel Zone, in meters, is calculated for each path using the following formula: where D is the microwave path length in kilometers and F GHz is the frequency in gigahertz. The WCFZ is defined by the cylindrical area (catenary) with its axis as the direct line between the microwave link endpoints and whose radius is R as calculated above. This is the zone where the siting of obstructions should be avoided. As shown in Table 1 below, Evans Associates has identified five unique microwave paths that intersect, or come close to, the project area, represented by the following microwave links: 2 Many microwave facilities were built before accurate methods were available to establish exact geographic coordinates (such as GPS). It is not unusual for database errors of up to 4 or 5 seconds to occur, which can effect the positioning of critical turbines located near Fresnel paths. PdV Engineering Report All Rights Reserved 2007 Page 5

6 ID Name Site 1 Name Site 2 Call Sign Site 1 Call Sign Site 2 BAND NAME Licensee WCFZ (m) 1 COTTONWIND ANTELOPE COTTONWI KMO48 Lower 6 GHz Southern California Edison Co COTTONWIND ROSAMOND COTTONWI KMY63 11 GHz Southern California Edison Co BURNT PEAK COTTONWIND WAA514 COTTONWI Lower 6 GHz Southern California Edison Co DBL MTN 29 OAT MTN WNEN856 WNEN869 Lower 6 GHz Southern California Gas Co USAF PLANT TEJON RANCH WNTT724 WNTT GHz Northrop Grumman Systems Corp Table 1 Microwave Links in or Near the Turbine Area These microwave paths have been overlaid on a USGS topographic map which is shown in attached Figure 2. Only the microwave paths shaded in blue, which are subject to approval by the FCC, actually are impacted by the turbine project. The two existing licensed microwave links, WNEN856 and WNTT724, come close to the turbine area boundaries but do not come within the worst-case clearance distance (WCFZ plus the radius of the rotor). When siting turbines, the following worst-case clearances are applicable to the identified impacted paths: ID WCFZ (m) Blade Radius (m) Total Clearance (x,y,z) meters Table 2 Paths Creating Blackout Zones and Clearances Required Final siting of the turbines should be done in coordination with a land surveyor to verify the coordinates of the endpoints of the microwave path. The accuracy of license coordinates as obtained from the FCC s database generally does not exhibit the required precision. The three proposed microwave links that would be impacted either originate or terminate at a proposed antenna site in the southeast corner of the approximately 80-acre Cottonwind substation parcel located in the north half of the northwest quarter of Section 4 T9N. In order to prevent RF impact to any of these links, no turbines should be placed in a rectangular area bounded by: 1. an east-to-west line 52.5 meters north of the proposed microwave tower 2. the eastern border of the Cottonwind substation parcel 3. the southern border of the Cottonwind substation parcel 4. a north-to-south line 90 meters west of the proposed microwave tower. PdV Engineering Report All Rights Reserved 2007 Page 6

7 The blackout zone describe above is shown in attached Figure 3. There may be other setback requirements (legal, construction- or safety-related, etc.) that could expand this exclusion zone, which are not within the purview of this report. The proposed microwave link from the Cottonwind substation to Rosamond (ID #2) forms a turbine blackout zone in the southernmost turbine area, in the east half of Section 2 T9N. As seen in the terrain profile graph of this microwave path, Figure 4, a turbine placed in the path would obstruct the microwave signal. The blackout zone is shown in attached Figure 5. The radius of the zone is 48.3 meters 3 on either side of the line of the path. The line of the path through the turbine area is uniquely identified by the geographical coordinates of the entry and exit coordinates shown in Figure 5. III. ANALYSIS OF FIXED RADIO FACILITIES There are no land mobile or public safety transmitter sites that fall within the property boundaries or within one mile of any property boundary. There is one land mobile station within two miles, namely WPTS384, whose fixed transmitter location, according to the licensed geographic coordinates, is about 1.7 miles from the nearest turbine property boundary 4. No significant adverse effects are expected to be caused to the station, however, it is recommended that PPM Energy notify the licensee of WPTS384 to give them the opportunity to comment on the potential impact of the wind project on the operation of the land mobile facility. IV. FAA AND DOD CONCERNS At the present time, FAA and Department of Defense (DoD) standards for aircraft and airport navigation facilities, including military radar, are in a state of flux. The long-awaited DoD wind farm interference report 5 was released to the public on September 27, The Department of Defense and the Department of Homeland Security Long Range Radar Joint Program Office JPO had previously adopted an interim policy of objecting to any turbines located within line of sight of any air defense or Homeland Security radar 6. At least 12 projects in Illinois, Wisconsin, North Dakota and South Dakota had been held up because of this interim policy % of the first Fresnel zone for the pertinent distances from the transmitter site (9.8 meters), plus the radius of the rotor (38.5 meters). 4 WPTS384 is licensed to Air France and is apparently used by the airline to coordinate internal airline activities. However, the address of the base station site and the site elevation as listed on the FCC license corresponds to a location at Los Angeles International Airport, and not near the PdV windfarm in Kern County. It is strongly suspected that the licensed coordinates are off by exactly one degree latitude. To clear up the matter, this affiant spoke with two people from Air France, one in New York and the other at Los Angeles International Aiport. Neither could state with absolute certainty whether or not Air France operates a two-way facility in Kern County. 5 This report is named The Effect of Windmill Farms On Military Readiness. 6 This consultant is not aware of any publicly accessible database identifying the locations of military radar sites. PdV Engineering Report All Rights Reserved 2007 Page 7

8 The standards contained in the 2006 report allow intervening terrain shielding, as well as placing turbines beyond line of sight, to be used to avoid impact to military radar, but these are the only mitigation measures that have been approved so far. PPM Energy may assume that FAA obstruction clearance also includes defense radar and military flight routes 7. However, it is absolutely crucial that the FAA clearance, once received, must not be allowed to expire. It would also be prudent to submit forms to the FAA as the first consideration in the site development process. At the same time, notification should be made to the JPO. V. OTHER GOVERNMENT RF FACILITIES Operation of RF frequencies for federal government use is managed by the National Telecommunication Information Agency (NTIA), which is part of the U.S. Department of Commerce. The technical specifications for most government facilities are unavailable to the public. In order to avoid the derailment of the PdV wind energy project due to late objections from a government agency, the NTIA should be notified of the proposed project during preconstruction planning. The NTIA has set in place a review process, wherein the Interdepartmental Radio Advisory Committee (IRAC), consisting of representatives from various government agencies, reviews new proposals for wind turbine projects for impact on government frequencies. In almost all cases, no adverse impact is found, and IRAC usually issues a determination within 30 days. However, notification to NTIA should not be regarded as an alternative to notifying JPO concerning military radar impact or the FAA. All three agencies should be notified. VI. CONCLUSIONS The following conclusions have been reached as a result of the analysis undertaken with respect to the PdV wind project: 1. There are no existing microwave paths that are impacted, but three proposed microwave paths would traverse the turbine property. Turbines should be sited to avoid the blackout zones shown in attached Figures 3 and 5, with the assistance of a land surveyor to determine the exact locations of the transmit and receive sites for the microwave stations. 2. According to the FCC database, the closest land mobile station, WPTS384, is about 1.7 miles from the nearest wind turbine boundary. During the pre-construction surveys, a 7 Evans has contacted private aeronautical consultants who agree with this assertion. However, there are no guarantees that FAA approval will not be rescinded if it is in the interest of national security. The best way to guard against this eventuality is to submit the turbine project proposal to the JPO office at Langley Air Force Base in Langley, Virginia at the time the FAA is notified. Care should be taken in contacting JPO once clearance is received, however, lest the case be re-opened. PdV Engineering Report All Rights Reserved 2007 Page 8

9 determination should be made of whether or not WPTS384 is in operation at the notified coordinates. Although the operation of this station is not expected to be significantly impacted by the turbines, the licensee should be notified of the proposed wind project as part of the public review process. There are no other land mobile or public safety stations identified as being within two miles of the turbine property boundaries A physical inspection should be done to determine if there are any undocumented nonbroadcast transmitters of any type in the turbine parcels or within a half-mile of the property boundaries. For example, cellular base station locations are not individually notified to the FCC. A database search was conducted by this affiant for communications towers registered at the FCC, and none were found in the area. However, unregistered towers should be checked by on-site inspection. 4. The wind farm proposal should be referred to NTIA and the Joint Program Office to assure that no unlisted RF facilities are impacted by the turbines. Respectfully Submitted, B. Benjamin Evans, P.E. Communications Consultant March 19, 2007 ATTACHED FIGURES: Figure 1 -- Turbine Area Layout Figure 2 -- Map of Microwave Paths in Area of Wind Farm Figure 3 -- Turbine Blackout Zone in Cottonwind Substation Parcel Figure 4 -- Microwave Path Profile Cottonwind Substation to Rosamond Figure 5 -- Turbine Blackout Zone in Section 2 T9N E:\EA\Client Services\Windmills\PPM Energy\ (formerly Tejon Ranch)\RFImpactStudyReport Revised.doc 8 Two miles is the industry standard for which comments from FCC-licensed facilities for possible RF impact by a wind project are solicited. This is not an FCC requirement, but rather a good neighbor policy. PdV Engineering Report All Rights Reserved 2007 Page 9

Evans Associates Figure 2 Microwave Paths in Area of

14 Figure 4 Microwave Path Profile of Proposed 11 GHz Link From Cottonwind Substation to Rosamond (Impact in Section 2 T9N Shown by Blue Outline) PdV Engineering Report All Rights Reserved 2007 Page 14

Figure 5 Turbine Blackout Zone in Section 2 T9N Parcel

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