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1.06 General Application Materials_Part7
Page 3 of 4 TOPO Map for ASN 2021-ANM-489-OE Page 4 of 4 Sectional Map for ASN 2021-ANM-489-OE Mail Processing Center Federal Aviation Administration Southwest Regional Office Obstruction Evaluation Group 10101 Hillwood Parkway Fort Worth, TX 76177 Aeronautical Study No. 2021-ANM-490-OE Page 1 of 4 Issued Date: 02/11/2021 Joshua Mayer AES High Mesa Solar, LLC 282 Century Place, Suite 2000 Louisville, CO 80027 ** DETERMINATION OF NO HAZARD TO AIR NAVIGATION ** The Federal Aviation Administration has conducted an aeronautical study under the provisions of 49 U.S.C., Section 44718 and if applicable Title 14 of the Code of Federal Regulations, part 77, concerning: Structure: Solar Panel AES High Mesa Solar, LLC PV power plant Location: Parachute, CO Latitude: 39-23-25.45N NAD 83 Longitude: 108-04-17.66W Heights:5630 feet site elevation (SE) 14 feet above ground level (AGL) 5644 feet above mean sea level (AMSL) This aeronautical study revealed that the structure does not exceed obstruction standards and would not be a hazard to air navigation provided the following condition(s), if any, is(are) met: Based on this evaluation, marking and lighting are not necessary for aviation safety. However, if marking/ lighting are accomplished on a voluntary basis, we recommend it be installed in accordance with FAA Advisory circular 70/7460-1 M. This determination expires on 08/11/2022 unless: (a) the construction is started (not necessarily completed) and FAA Form 7460-2, Notice of Actual Construction or Alteration, is received by this office. (b) extended, revised, or terminated by the issuing office. (c) the construction is subject to the licensing authority of the Federal Communications Commission (FCC) and an application for a construction permit has been filed, as required by the FCC, within 6 months of the date of this determination. In such case, the determination expires on the date prescribed by the FCC for completion of construction, or the date the FCC denies the application. NOTE: REQUEST FOR EXTENSION OF THE EFFECTIVE PERIOD OF THIS DETERMINATION MUST BE E-FILED AT LEAST 15 DAYS PRIOR TO THE EXPIRATION DATE. AFTER RE-EVALUATION OF CURRENT OPERATIONS IN THE AREA OF THE STRUCTURE TO DETERMINE THAT NO SIGNIFICANT AERONAUTICAL CHANGES HAVE OCCURRED, YOUR DETERMINATION MAY BE ELIGIBLE FOR ONE EXTENSION OF THE EFFECTIVE PERIOD. Page 2 of 4 This determination is based, in part, on the foregoing description which includes specific coordinates, heights, frequency(ies) and power. Any changes in coordinates, heights, and frequencies or use of greater power, except those frequencies specified in the Colo Void Clause Coalition; Antenna System Co-Location; Voluntary Best Practices, effective 21 Nov 2007, will void this determination. Any future construction or alteration, including increase to heights, power, or the addition of other transmitters, requires separate notice to the FAA.This determination includes all previously filed frequencies and power for this structure. If construction or alteration is dismantled or destroyed, you must submit notice to the FAA within 5 days after the construction or alteration is dismantled or destroyed. This determination does include temporary construction equipment such as cranes, derricks, etc., which may be used during actual construction of the structure. However, this equipment shall not exceed the overall heights as indicated above. Equipment which has a height greater than the studied structure requires separate notice to the FAA. This determination concerns the effect of this structure on the safe and efficient use of navigable airspace by aircraft and does not relieve the sponsor of compliance responsibilities relating to any law, ordinance, or regulation of any Federal, State, or local government body. If we can be of further assistance, please contact our office at (206) 231-2990, or paul.holmquist@faa.gov. On any future correspondence concerning this matter, please refer to Aeronautical Study Number 2021-ANM-490- OE. Signature Control No: 466811488-469060900 ( DNE ) Paul Holmquist Specialist Attachment(s) Map(s) Page 3 of 4 TOPO Map for ASN 2021-ANM-490-OE Page 4 of 4 Sectional Map for ASN 2021-ANM-490-OE AES High Mesa Solar – Land Use Change – Major Impact permit application (10/22/2021) AES High Mesa Solar – Garfield County 53 Please see the following pages for the Stormwater Memo prepared by NEI Engineering for AES High Mesa Solar, LLC published in October 2021. STORMWATER MEMO Appendix C6 neiengineering.com + 303-431-7895 12600 W Colfax Avenue, Suite C500, Lakewood, CO 80215 To: Joshua Mayer AES Clean Energy The AES Corporation 282 Century Place, Suite 2000 Louisville, CO 80027 From: NEI Electric Power Engineering, Inc. 12600 W Colfax Avenue, Suite C500 Lakewood, CO 80215 Date: October 8, 2021 Project Name: High Mesa Solar Project No.: 3704.002 Subject: Stormwater Memo (30% Review) High Mesa Solar is a proposed solar facility located at 1691 County Road 300, Garfield County approximately 4 miles south of Parachute, Colorado. Construction of this project will be limited to approximately 75.4 acres of the 364-acre lot. The project is expected to change approximately 40,371 (0.93 ac; 1.23% lot coverage) of pervious area into impervious area. The impervious area will consist of four (4) concrete equipment pads, two (2) gravel access roads, and foundations for solar arrays. Onsite drainage patterns will be maintained with exception to minor grading related to proposed gravel roads; therefore a Drainage Report is not required per county standards. This memo is intended to provide Garfield County with drainage and land disturbance information with respect to this project. Existing Conditions The project site is mostly developed agricultural fields throughout the property. The undeveloped land cover consists of native vegetation, sparse weeds and grasses. The topography consists of rolling hills, plains and mesas. The existing soils on site are primarily types A and C. The site generally drains from west to east mesas with a topographic relief of approximately 170 ft. Stormwater runoff sheet flows southwest and AES Clean Energy High Mesa Solar STORMWATER MANAGEMENT PLAN p. ii collects in a natural channel. The channel conveys flow west and discharges to the Colorado River approximately 1 mile west of the project site. Proposed Conditions Construction activities associated with the proposed solar facility will affect approximately 75.4 acres onsite. However, much of the disturbed area will involve construction of support structures for solar panel arrays, leaving the surface beneath the panels undeveloped and pervious. These solar arrays are not expected to result in a significant creation of impervious area. The project also proposes four (4) concrete equipment pads, an O&M pad, a switch gear pad, and gravel access roads. In total, the project will result in the generation of approximately 40,370 sf of impervious area which covers 1.23% of the project site. Grading activities will be localized around the gravel access road and existing drainage patterns will be maintained. Impervious Area Calculations Quantity Area Impervious Factor Impervious Area Units Equipment Pads 4 2,660 1.0 10,640 sf O&M Pad 1 800 1.0 800 sf Switchgear Pad 1 24 1.0 24 sf Gravel Access Road 1 72,069 0.4 28,828 sf Total Area 40,292 sf Total LOD 3,281,706 sf Coverage Ratio 1.23% A gravel access road will cross existing stormwater conveyances; therefore, the project also proposes one (1) culvert, which will be discussed below. Stormwater Management Strategy Stormwater Management (treatment & detention) are not required because the proposed impervious area is not expected to significantly alter stormwater quality and quantity and existing drainage patterns are maintained. Using a grass seed mix to restore all areas of disturbance, stormwater quality will be improved through a native seed mix. The mix will also decrease the quantity of stormwater runoff previously experienced on site. Flood Zone The project site would be reported on Flood Insurance Rate Map (FIRM) community panel 0802051700B. Currently the panel is not printed, and flood hazard areas are unidentified. However, the project site is approximately 140 and 190 ft above the intermittent creeks to the east and west, respectively. Therefore, this project is not expected to negatively impact these creeks. AES Clean Energy High Mesa Solar STORMWATER MANAGEMENT PLAN p. iii Culvert Design This project proposes an access road which intersects a drainage ditch. This crossing requires a culvert to maintain drainage through the site. The culverts are designed to convey the 25-yr peak flow from their contributing drainage basin. The 25-yr storm event (4% annual exceedance probability) is the typical design storm for stormwater conveyances per the County’s Land Use & Development Code (2013). The UDFCD’s modified rational method, an allowable reference per CDOT’s Drainage Design Manual (DDM, 2019), was used to quantify the 25-yr peak flow for each culvert’s contributing drainage basin. The following equation is referenced: Q25 =C25 ∙ I25 ∙ A Where Q25 is the 25-yr peak flow (cfs), A is the contributing drainage area (acres), I 25 is the rainfall intensity in inches per hour for a duration equal to the time of concentration, and C 25 is the runoff coefficient from equations based on NRCS soil groups and storm return period. For soil groups C/D, the runoff coefficient was determined to from the equation: CC/D = 0.64i + 0.31 The runoff coefficient, C, used was 0.33 and the rainfall intensity, I, used was 3.80 inches per hour. Rainfall depth was derived from “NOAA ATLAS 14 POINT PRECIPITATION FREQUENCY ESTIMATES”. Culverts are assumed to be HDPE, with the exception of Culvert E being RCP, which both have a roughness coefficient (n) of 0.012 per the DDM. The results of the hydraulics calculations are shown in Table 1 below. Table 1 – Culvert Sizing Results Summary The project proposes 0.93 ac of impervious area, which consists of concrete equipment pads, a gravel access road, and foundations for solar arrays. This impervious area constitutes of 1.23% of the solar development area. The project will not alter existing drainage patterns, thus does not require a drainage report. The proposed access road will require the installation of culverts. Initial sizing has been provided and will be refined as the site design develops. Attachments • Basin Exhibit FYRWALD EXEMPTION PLAT LOT 3LAND SURVEY PLAT DEPOSIT NO. 312FRANK W & YONEKO McNEILPARCEL NO. 240935300128 FYRWALD EXEMPTION PLAT LOT 4LAND SURVEY PLAT DEPOSIT NO. 312GERALD GRUNKSA ET ALPARCEL NO. 240935300129 FYRWALD EXEMPTION PLAT LOT 3LAND SURVEY PLAT DEPOSIT NO. 312FRANK W & YONEKO McNEILPARCEL NO. 240935300128 FYRWALD EXEMPTION PLAT LOT 4LAND SURVEY PLAT DEPOSIT NO. 312GERALD GRUNKSA ET ALPARCEL NO. 240935300129 CULVERT A 18" DIA. @ 2.00% 1.1 1.2 STORMWATER MANHOLE W/ GRATE INLET TOP 10/04/21 C01-0510/04/21 ML RB ISSUED FOR 30% REVIEWA-- - ---- - ---- - ---- - ---- - --JOB NO. SCALEDATEREVISIONSNO. DATEDWN. CHK.ELECTRIC POWER ENGINEERING, INC.12600 W. COLFAX AVE, STE. C500LAKEWOOD, CO 80215(303) 431-7895 www.neieng.com1691 300 COUNTY ROAD, PARACHUTE, CO1" = 200' 3704.002 PV CIVILSITE PLANHIGH MESAPRELIMINARY NOT FOR CONSTRUCTION FOR REVIEW & APPROVAL ONLY SCALE: 200' 100' 0 200' 400' 600' 1"=200' N NOTES 1. SURVEY AND TOPOGRAPHY DATA TAKEN FROM "HIGH MESA-ALTA SURVEY - ACQUISITION-ISSUED_04-20-2021" BY SGM INC.; DATED APRIL 20, 2021. 2. WETLANDS SHOWN AS PROVIDED IN THE ALTA SURVEY. LEGEND: EXISTING FEATURES EXISTING FENCE EXISTING CONTOUR MINOR EXISTING CONTOUR MAJOR EXISTING ROAD EASEMENT EXISTING FENCE EXISTING UTILITY POLE EXISTING OVERHEAD ELECTRIC EXISTING LIMITS OF GAS PIPELINE EXISTING UNDERGROUND WATER LINE EXISTING PROPERTY LINE EXISTING WETLANDS EXISTING DITCH EXISTING PROPERTY LINE EXISTING WETLANDS EXISTING DITCH EXISTING DITCH SETBACK EXISTING WETLANDS SETBACK PROPOSED LIMIT OF DISTURBANCE PROPOSED CULVERT PROPOSED FEATURES RIPRAP EROSION CONTROL #BASIN ID BASIN BOUNDARY AES High Mesa Solar – Land Use Change – Major Impact permit application (10/22/2021) AES High Mesa Solar – Garfield County 54 Please see the following pages for proof of receipt from the Colorado Department of Health and Environment a Stormwater Management Plan prepared by NEI Engineering for AES High Mesa Solar, LLC on November 8th, 2021. The full stormwater management plan will be provided as separate addenda to this application given its size. STORMWATER MANAGEMENT PLAN – RECEIPT OF SUBMISSION TO CDPHE Appendix C6a AES High Mesa Solar – Land Use Change – Major Impact permit application (10/22/2021) AES High Mesa Solar – Garfield County 55 Please see the following pages for the Forge Solar Glare Analysis for AES High Mesa Solar, LLC conducted in August 2021. FORGESOLAR GLARE ANALYSIS Appendix C7 FORGESOLAR GLARE ANALYSIS Project: High Mesa Solar 10MW PV with BESS Site configuration: HMS Analysis conducted by Derrick Worden (Derrick.worden@aes.com) at 17:26 on 20 Aug, 2021. U.S. FAA 2013 Policy Adherence The following table summarizes the policy adherence of the glare analysis based on the 2013 U.S. Federal Aviation Administration Interim Policy 78 FR 63276. This policy requires the following criteria be met for solar energy systems on airport property: • No "yellow" glare (potential for after-image) for any flight path from threshold to 2 miles • No glare of any kind for Air Traffic Control Tower(s) ("ATCT") at cab height. • Default analysis and observer characteristics (see list below) ForgeSolar does not represent or speak officially for the FAA and cannot approve or deny projects. Results are informational only. COMPONENT STATUS DESCRIPTION Analysis parameters PASS Analysis time interval and eye characteristics used are acceptable 2-mile flight path(s) N/A No flight paths analyzed ATCT(s)N/A No ATCT receptors designated Default glare analysis parameters and observer eye characteristics (for reference only): • Analysis time interval: 1 minute • Ocular transmission coefficient: 0.5 • Pupil diameter: 0.002 meters • Eye focal length: 0.017 meters • Sun subtended angle: 9.3 milliradians FAA Policy 78 FR 63276 can be read at https://www.federalregister.gov/d/2013-24729 SITE CONFIGURATION Analysis Parameters DNI: peaks at 1,000.0 W/m^2 Time interval: 1 min Ocular transmission coefficient: 0.5 Pupil diameter: 0.002 m Eye focal length: 0.017 m Sun subtended angle: 9.3 mrad Site Config ID: 57669.10309 PV Array(s) Name: PV array 1 Axis tracking: Single-axis rotation Tracking axis orientation: 180.0° Tracking axis tilt: 0.0° Tracking axis panel offset: 0.0° Max tracking angle: 60.0° Resting angle: 60.0° Rated power: - Panel material: Smooth glass with AR coating Reflectivity: Vary with sun Slope error: correlate with material Vertex Latitude (°) Longitude (°) Ground elevation (ft) Height above ground (ft) Total elevation (ft) 1 39.398583 -108.074465 5447.32 12.00 5459.32 2 39.397837 -108.075774 5438.03 12.00 5450.03 3 39.397390 -108.075903 5437.59 12.00 5449.59 4 39.396958 -108.075452 5452.05 12.00 5464.05 5 39.396245 -108.075838 5457.10 12.00 5469.10 6 39.396129 -108.076396 5454.68 12.00 5466.68 7 39.395582 -108.076675 5460.01 12.00 5472.01 8 39.394504 -108.076740 5472.17 12.00 5484.17 9 39.394554 -108.077491 5459.02 12.00 5471.02 10 39.394140 -108.077426 5460.05 12.00 5472.05 11 39.393244 -108.076396 5471.44 12.00 5483.44 12 39.392597 -108.074615 5483.81 12.00 5495.81 13 39.393310 -108.073907 5502.58 12.00 5514.59 14 39.393227 -108.072577 5532.93 12.00 5544.93 15 39.392763 -108.072190 5545.50 12.00 5557.50 16 39.392548 -108.072791 5542.13 12.00 5554.13 17 39.391917 -108.072555 5556.32 12.00 5568.32 18 39.391271 -108.072169 5564.74 12.00 5576.74 19 39.391204 -108.071010 5581.84 12.00 5593.84 20 39.390889 -108.070388 5592.38 12.00 5604.38 21 39.390226 -108.070131 5589.87 12.00 5601.87 22 39.390292 -108.068006 5625.28 12.00 5637.28 23 39.390873 -108.069272 5609.17 12.00 5621.17 24 39.392597 -108.070431 5572.63 12.00 5584.63 25 39.392166 -108.070989 5569.00 12.00 5581.00 26 39.392780 -108.071976 5549.58 12.00 5561.58 27 39.393543 -108.071332 5549.07 12.00 5561.07 28 39.393858 -108.071053 5548.78 12.00 5560.78 29 39.393609 -108.070646 5558.27 12.00 5570.27 30 39.393808 -108.069959 5557.89 12.00 5569.89 31 39.395217 -108.070324 5529.28 12.00 5541.28 32 39.397837 -108.071268 5484.07 12.00 5496.07 33 39.397605 -108.072083 5486.29 12.00 5498.29 34 39.397605 -108.072791 5480.38 12.00 5492.38 35 39.398036 -108.073821 5460.88 12.00 5472.88 Discrete Observation Receptors Name ID Latitude (°) Longitude (°)Elevation (ft)Height (ft) OP 1 1 39.389494 -108.075232 5506.46 10.00 OP 2 2 39.390771 -108.077925 5455.36 10.00 OP 3 3 39.392427 -108.080817 5402.80 10.00 OP 4 4 39.383348 -108.077926 5603.67 10.00 OP 5 5 39.384785 -108.076048 5606.83 10.00 OP 6 6 39.386944 -108.082266 5475.52 10.00 OP 7 7 39.387879 -108.083316 5452.34 10.00 OP 8 8 39.395993 -108.077494 5452.55 10.00 OP 9 9 39.401712 -108.072797 5338.57 10.00 Route Receptor(s) Name: Route 1 Path type: Two-way Observer view angle: 50.0° Note: Route receptors are excluded from this FAA policy review. Use the 2-mile flight path receptor to simulate flight paths according to FAA guidelines. Vertex Latitude (°) Longitude (°) Ground elevation (ft) Height above ground (ft) Total elevation (ft) 1 39.409473 -108.075024 5079.76 6.00 5085.76 2 39.409440 -108.076955 5090.61 6.00 5096.61 3 39.409755 -108.078629 5106.82 6.00 5112.82 4 39.409755 -108.079766 5116.64 6.00 5122.64 5 39.409738 -108.080453 5112.59 6.00 5118.59 6 39.409887 -108.081440 5105.16 6.00 5111.16 7 39.409490 -108.081891 5099.55 6.00 5105.55 8 39.408677 -108.082363 5087.47 6.00 5093.47 9 39.407649 -108.082577 5075.32 6.00 5081.32 10 39.406555 -108.082406 5063.49 6.00 5069.49 11 39.404930 -108.082019 5059.56 6.00 5065.56 12 39.404168 -108.081934 5059.89 6.00 5065.89 13 39.401979 -108.082019 5055.95 6.00 5061.95 14 39.401299 -108.081976 5054.74 6.00 5060.74 15 39.400387 -108.082019 5056.80 6.00 5062.81 16 39.397966 -108.082019 5074.77 6.00 5080.77 17 39.397585 -108.082277 5085.25 6.00 5091.25 18 39.396457 -108.084380 5082.71 6.00 5088.71 19 39.395860 -108.086526 5046.33 6.00 5052.33 20 39.395479 -108.087062 5042.55 6.00 5048.55 21 39.394816 -108.089058 5038.15 6.00 5044.15 22 39.394584 -108.091504 5083.32 6.00 5089.32 23 39.394235 -108.093242 5079.83 6.00 5085.83 24 39.393920 -108.093757 5066.03 6.00 5072.03 Name: Route 2 Path type: One-way (toward increasing index) Observer view angle: 50.0° Note: Route receptors are excluded from this FAA policy review. Use the 2-mile flight path receptor to simulate flight paths according to FAA guidelines. Vertex Latitude (°) Longitude (°) Ground elevation (ft) Height above ground (ft) Total elevation (ft) 1 39.399808 -108.115944 5082.94 6.00 5088.94 2 39.410320 -108.096761 5094.93 6.00 5100.93 3 39.411182 -108.095559 5103.60 6.00 5109.60 4 39.412293 -108.094529 5108.45 6.00 5114.45 5 39.414415 -108.092984 5105.32 6.00 5111.32 Name: Route 3 Path type: One-way (toward increasing index) Observer view angle: 50.0° Note: Route receptors are excluded from this FAA policy review. Use the 2-mile flight path receptor to simulate flight paths according to FAA guidelines. Vertex Latitude (°) Longitude (°) Ground elevation (ft) Height above ground (ft) Total elevation (ft) 1 39.424347 -108.082132 5106.39 6.00 5112.39 2 39.420352 -108.088118 5109.69 6.00 5115.69 3 39.418115 -108.090801 5095.50 6.00 5101.50 4 39.414368 -108.093848 5111.19 6.00 5117.19 5 39.412213 -108.095328 5108.97 6.00 5114.97 6 39.411434 -108.096122 5104.08 6.00 5110.08 7 39.410489 -108.097495 5093.26 6.00 5099.26 8 39.405432 -108.106636 5083.78 6.00 5089.78 GLARE ANALYSIS RESULTS Summary of Glare PV Array Name Tilt Orient "Green" Glare "Yellow" Glare Energy (°) (°)min min kWh PV array 1 SA tracking SA tracking 0 0 - Total annual glare received by each receptor Receptor Annual Green Glare (min) Annual Yellow Glare (min) OP 1 0 0 OP 2 0 0 OP 3 0 0 OP 4 0 0 OP 5 0 0 OP 6 0 0 OP 7 0 0 OP 8 0 0 OP 9 0 0 Route 1 0 0 Route 2 0 0 Route 3 0 0 Results for: PV array 1 Receptor Green Glare (min) Yellow Glare (min) OP 1 0 0 OP 2 0 0 OP 3 0 0 OP 4 0 0 OP 5 0 0 OP 6 0 0 OP 7 0 0 OP 8 0 0 OP 9 0 0 Receptor Green Glare (min) Yellow Glare (min) Route 1 0 0 Route 2 0 0 Route 3 0 0 Point Receptor: OP 1 0 minutes of yellow glare 0 minutes of green glare Point Receptor: OP 2 0 minutes of yellow glare 0 minutes of green glare Point Receptor: OP 3 0 minutes of yellow glare 0 minutes of green glare Point Receptor: OP 4 0 minutes of yellow glare 0 minutes of green glare Point Receptor: OP 5 0 minutes of yellow glare 0 minutes of green glare Point Receptor: OP 6 0 minutes of yellow glare 0 minutes of green glare Point Receptor: OP 7 0 minutes of yellow glare 0 minutes of green glare Point Receptor: OP 8 0 minutes of yellow glare 0 minutes of green glare Point Receptor: OP 9 0 minutes of yellow glare 0 minutes of green glare Route: Route 1 0 minutes of yellow glare 0 minutes of green glare Route: Route 2 0 minutes of yellow glare 0 minutes of green glare Route: Route 3 0 minutes of yellow glare 0 minutes of green glare Assumptions 2016 © Sims Industries d/b/a ForgeSolar, All Rights Reserved. "Green" glare is glare with low potential to cause an after-image (flash blindness) when observed prior to a typical blink response time. "Yellow" glare is glare with potential to cause an after-image (flash blindness) when observed prior to a typical blink response time. Times associated with glare are denoted in Standard time. For Daylight Savings, add one hour. Glare analyses do not account for physical obstructions between reflectors and receptors. This includes buildings, tree cover and geographic obstructions. Several calculations utilize the PV array centroid, rather than the actual glare spot location, due to V1 algorithm limitations. This may affect results for large PV footprints. Additional analyses of array sub-sections can provide additional information on expected glare. The subtended source angle (glare spot size) is constrained by the PV array footprint size. Partitioning large arrays into smaller sections will reduce the maximum potential subtended angle, potentially impacting results if actual glare spots are larger than the sub-array size. Additional analyses of the combined area of adjacent sub-arrays can provide more information on potential glare hazards. (See previous point on related limitations.) Glare locations displayed on receptor plots are approximate. Actual glare-spot locations may differ. Glare vector plots are simplified representations of analysis data. Actual glare emanations and results may differ. The glare hazard determination relies on several approximations including observer eye characteristics, angle of view, and typical blink response time. Actual results and glare occurrence may differ. Hazard zone boundaries shown in the Glare Hazard plot are an approximation and visual aid based on aggregated research data. Actual ocular impact outcomes encompass a continuous, not discrete, spectrum. Refer to the Help page at www.forgesolar.com/help/ for assumptions and limitations not listed here. AES High Mesa Solar – Land Use Change – Major Impact permit application (10/22/2021) AES High Mesa Solar – Garfield County 56 Please see the following pages for a Letter of Attestation from Holy Cross Energy in support for AES High Mesa Solar, LLC provided in August 2021. HOLY CROSS ENERGY LETTER OF ATTESTATION Appendix C8 3799 HIGHWAY 82∙P.O. DRAWER 2150 GLENWOOD SPRINGS, COLORADO 81602 (970) 945-5491∙FAX (970) 947-5480 August 5, 2021 AES Clean Energy 282 Century Place, Suite 2000 Louisville, CO 80027 RE: Letter of Support Dear Mr. Mayer, Please let this letter serve as an attestation that Holy Cross Energy (HCE) is supportive of AES’s High Mesa and Peace Bear Ranch projects in development in Garfield County. HCE confirms there is a Power Purchase Agreement in place with AES for both projects, with scheduled Commercial Operation dates of December 31, 2022. While this letter serves to support AES’s permit efforts with Garfield County, it does not constitute permission to operate in parallel with HCE’s electric distribution system. HCE and AES will continue to coordinate to ensure the requirements of the Power Purchase Agreement are met, a Generator Interconnection Agreement is signed by both parties, and the requirements of that Generator Interconnection Agreement are met prior to the facility operating in parallel with HCE’s electric distribution system. The Peace Bear Ranch project is additionally contingent on results from Public Service Company of Colorado’s Affected System Study. Please contact me with any questions and concerns. Sincerely, HOLY CROSS ENERGY Sam Whelan Manager, Power Supply AES High Mesa Solar – Land Use Change – Major Impact permit application (10/22/2021) AES High Mesa Solar – Garfield County 57 Please see the following pages for AES’ Fire Risk Assessment of Battery Storage Systems similar to those designed and specified for AES High Mesa Solar, LLC. AES BATTERTY STORAGE SYSTEM FIRE RISK ASSESSMENT Appendix C9 AES Distributed Energy Contains Proprietary Information Page 1 of 18 Fire Risk Assessment for Outdoor, Remote, Non-Walk-in BESS Enclosures 26 Nov 2019 Rev 1 for SMART Projects 10 April 2020 Rev 2 Modified for NY DER Projects 1 May 2020, Rev 2. Part 3 Covering NFPA 1 Ch 52 Added AES Distributed Energy Contains Proprietary Information Page 2 of 18 Contents Purpose ......................................................................................................................................................... 4 Part 1. Fire Safety Analysis Based on NFPA 551 and NFPA 550 .................................................................... 4 1. Fire Safety Objectives ............................................................................................................................ 4 Risk Criteria ........................................................................................................................................... 4 Protection of Human Life ...................................................................................................................... 4 Protection of Property .......................................................................................................................... 5 Protection of Business .......................................................................................................................... 5 Fire Scenarios ........................................................................................................................................ 5 2. Prevent Fire Ignition .............................................................................................................................. 6 Combustible Materials and Mitigation ................................................................................................. 6 Potential Causes of Ignition and Mitigation .......................................................................................... 6 3. Manage Fire Impact .............................................................................................................................. 7 Fire Detection ........................................................................................................................................ 7 Fire Control ........................................................................................................................................... 8 Fire Emergency Response ..................................................................................................................... 9 Part 2. Fire Safety Analysis Based on NFPA 855.......................................................................................... 10 Chapter 4 ................................................................................................................................................. 10 Section 4.1 General and 4.14 Hazard Mitigation Analysis ...................................................................... 10 Section 4.2 Equipment ............................................................................................................................ 12 Section 4.3 and 4.4 Installation Requirements and Location ................................................................. 12 Sections 4.5 4.6, 4.7, 4.8, & 4.9 ............................................................................................................... 13 Section 4.10 Smoke and Fire Detection .................................................................................................. 13 Section 4.11 Fire Control and Suppression ............................................................................................. 13 Section 4.12 Explosion Control ............................................................................................................... 13 Section 4.13 Water Supply ...................................................................................................................... 13 Sections 4.14, 4.15 .................................................................................................................................. 14 Section 4.16 Remediation Measures ...................................................................................................... 14 Chapter 5. System Interconnections ...................................................................................................... 14 Chapter 6, 7 & 8 ...................................................................................................................................... 14 Chapter 9 Electrochemical Energy Storage Systems .............................................................................. 14 Chapters 10, 11, 12, 13, 14, & 15 ............................................................................................................ 14 Part 3. Fire Safety Analysis Based on NFPA 1 Chapter 52 ........................................................................... 15 AES Distributed Energy Contains Proprietary Information Page 3 of 18 Section 52.1 General and 52.2 Permits................................................................................................... 15 Section 52.2 PdAcid & NiCd, Section 52.3.3 Capacitors ......................................................................... 15 Section 52.3.2.1 Location ........................................................................................................................ 15 Section 52.3.2.2 and 3 Max Allowable Quantities, Battery Arrays ......................................................... 15 Section 52.3.2.4 Hazard Mitigation Analysis ........................................................................................... 15 Section 52.3.2.5 Listings .......................................................................................................................... 15 Section 52.3.2.6 Installation ................................................................................................................... 16 Sections 52.3.2.6. 6, 7 & 8. Seismic, Caps and Mixed Batteries............................................................. 16 Section 52.3.2.7 Fire Suppression and Detection ................................................................................... 16 Section 52.3.2.8 & 9 Ventilation and Spill Control .................................................................................. 16 Section 52.3.2.10 and 11 Thermal Runaway for Lithium Ion Batteries .................................................. 16 Section 52.3.2.12 Testing, Maintenance, and Repairs. ........................................................................... 16 Definitions ................................................................................................................................................... 17 Reference Documents ................................................................................................................................. 17 AES Distributed Energy Contains Proprietary Information Page 4 of 18 Purpose This assessment provides justification and explanation for the Fire Safety Design, Implementation and Operation of the AES BESS enclosure for outdoor, remote, non-walk-in type enclosures for energy storage facilities owned and operated by AES in an area under access control to only qualified individuals. Part 1. Fire Safety Analysis Based on NFPA 551 and NFPA 550 This part of the analysis uses the concepts outlined in NFPA 551 on Evaluation of Fire Risk Assessments, and NFPA 550 on a Fire Safety Concepts Tree (Figure 1). First, the fire safety objectives are defined. Then, there is an examination on preventing a fire, and how to manage the impact of the fire if one does occur. Figure 1 Fire Safety Concepts Tree 1. Fire Safety Objectives The fire safety objectives for this product are: 1. No harm to personnel, including operators, first responders and bystanders outside the project boundary. 2. Minimize impact to the environment. 3. Minimize the fire risk to assets. Risk Criteria • No harm to personnel is acceptable • Negligible harm to assets with an Occasional probability • Marginal harm to assets with a Remote probability • Critical and Catastrophic harm to assets should be Improbable Protection of Human Life Since these enclosures are non-walk-in, and access is restricted, the fire hazard harm to people would be the result of a fire, or explosion that escapes the boundary of the enclosure to a person in the vicinity. Fire Safety Objectives Prevent Fire Ignition Manage Fire Impact Control Heat- Energy Sources Control Source- Fuel Interactions Control Fuel Manage Fire Manage Exposed AES Distributed Energy Contains Proprietary Information Page 5 of 18 Thus, if a fire were to occur, containing it, preventing an explosion, and making sure people are not in the vicinity during a fire is the priority. Protection of Property There is a significant investment in the assets within the enclosure. The priority for protecting these assets from fire damage is preventing the fire in the first place. If there is a fire of any significance, it would be undesirable to re-use the batteries and equipment. After a fire event, the probability of a compromised material that could due further damage to the system is high. Therefore, there is no value is preserving the equipment in the enclosure if a fire event happens. There is value in preserving the property assets within the vicinity of the BESS enclosure, such as the PCS and transformers. Thus, if a fire were to occur, containing it and preventing an explosion are the asset protection priorities. Protection of Business Any fire event would negatively impact the business in terms of operating revenue, reputation, and the ability to execute additional projects. Again, the priority is not to have a fire in the first place. Any fire that did occur would require the replacement of the BESS equipment. The generating plant would not be operational, which would result in lost revenue. Fire Scenarios The fire assessment considers the following Fire Scenarios, as described in NFPA 551: (1) Fire ignition. Often based on the most probable event in a particular setting, for example, cigarette ignition of a couch in a living room. Prevention education would reduce the probability of occurrence of this event and the consequential risks. (2) Fire growth. Based on all probable developments of a fire, from smoldering to flashover fires. Fire protection systems such as sprinklers, compartmentation, and door closers may help to contain these fires and to reduce their consequential risks. The reduction in risk depends on the reliability and effectiveness of the fire control systems. (3) Smoke spread. Based on smoke spread to critical egress routes and other parts in a building. Fire protection systems such as smoke control and stairwell pressurization may help to contain the smoke and to reduce its consequential risks. The reduction in risk depends on d1e reliability and effectiveness of the smoke control systems. (4) Exposure of occupants. Based on smoke and fire blocking egress routes. Fire protection systems such as fire alarms, voice communication, clear egress routes, and refuge areas may help to provide early warning to occupants and to direct them either to evacuate the building or to seek refuge in certain areas. The reduction in risk depends on the reliability and effectiveness of the warning and evacuation systems. (5) Failure of fire department to respond. Based on no response or late response. Proper notification procedure and adequate fire department resources would help to rescue the trapped occupants or to control the fire. The reduction in risk depends on the reliability of the notification procedure and the adequacy of fire department resources. AES Distributed Energy Contains Proprietary Information Page 6 of 18 2. Prevent Fire Ignition Combustible Materials and Mitigation The BESS enclosure structural elements are mostly metal, or other non-combustible materials. Combustible materials in the BESS enclosure include: 1. Electrochemical components of the batteries, namely the electrolyte, o The combustion properties of the Samsung batteries have been studied and tested according to UL9540A. Although most of the report is confidential, a redacted portion of that report is submitted as a reference in this report, which includes gas compositions and flame spread properties. In a multi-rack test, fire that was initiated in one rack did not spread to the adjacent racks. 2. Plastic in the housing of the battery modules, o The effects of the plastic housing are included Samsung’s UL9540A findings. 3. Some enclosure barrier walls to control air flow, o The material is a construction grade polycarbonate and contains a Flame Retardant, listed as an ASTM E84-01 Class A material. 4. Some auxiliary component housings o Minimal material in the form of plastic fittings and covers. 5. Polyurethane spray foam under the steel floor o Contains fire retardant to meet E-84 Class 1 approvals. 6. Electrical cable insulation o All cables are rated for the voltage and installation location, according to the NFPA 70E type and UL listing. o Most common conductor insulation types are NFPA 70E types MTW and RHW-2. 7. Potential unwarranted combustible materials not part of the system that would be placed inside the container counter to signage, policy, and training. o The site is fenced and monitored. The container is locked. Door switches alarm if a door is opened and the system shuts down automatically if a door is opened during operation. Potential Causes of Ignition and Mitigation The most common ignition of fires in BESS containers are: 1) Electrical fires caused by resistance heating due to: a) Conductors sized too small; o The design has been reviewed and all conductor sizes are sufficient to prevent overheating b) Conductors with loose interconnections connections. o All electrical connections require torque marks to be checked during QC steps o All electrical connections require lock-nuts or spring washers to ensure tight connections o Annual Maintenance checks review major electrical connections to ensure connections remain tight over the life of the project 2) Chemical fires caused by heating of the batteries due to: a) Exceeding State of Charge (SOC) limits by over-charging or discharging the batteries AES Distributed Energy Contains Proprietary Information Page 7 of 18 o The SOC is managed and tracked by the BMS. Alarms and automatic shutdowns occur if the SOC limits are exceeded. b) Exceeding Rate of Charge/Discharge (C-rate) limits o The C-rate is managed and tracked by the BMS. Alarms and automatic shutdowns occur if the SOC limits are exceeded. c) Poor State of Health (SOH) due to degradation of the batteries o The SOH is managed and tracked by the BMS. Alarms and automatic shutdowns occur if the SOH drops below a minimum threshold. d) Exceeding acceptable interior environmental controls, hot air temperature or condensation o An HVAC system controls the interior environment. This system in monitored by the PPC against lockouts, high or low air temperatures, and high humidity. Alarms and automatic shutdowns occur if the temperature or humidity threshold limits are exceeded. e) Failure of a battery component o Component failures would result in temperature and/or voltage variances. Temperatures and voltages of all cells are monitored at 1 second intervals by the BMS. Alarms and automatic shutdowns occur if the temperatures or temperature variations exceed safe thresholds. Alarms and automatic shutdowns occur if the voltages or voltage variations exceed safe thresholds. Alarms detected by the BMS are watched by the PPC and SCADA to alert operational staff of hazards, and the PPC has a watchdog timer to monitor communication status to the BMS. The PPC has additional redundant protection measures based on temperatures and voltages that it monitors. 3) Arson a) The container is set fire due to criminal activity. o The site is fenced and monitored. The container is locked. Door switches alarm if a door is opened and the system shuts down automatically if a door is opened during operation. 3. Manage Fire Impact Fire Detection In addition to fire detection, strategies also include detection of flammable gases that could increase the chance of a fire. 1) Smoke Detectors. There are four detectors in the enclosure at locations to meet the design guidelines of NFPA 72. The detectors are tied to the Fire Control Panel, which provides alarm signals to the PPC through the enclosure PLC. 2) Air Temperature Sensors. There are 6 temperature sensors located in the enclosure. Heat from a fire could be detected by these sensors. High temperature alarms are handled by the PPC. 3) Battery Cell Temperature Sensors. There are 3 temperature sensors in every module. These temperature sensors would capture off-gassing threshold temperature and run-away temperature thresholds. Temperatures and alarms are monitored by the BMS and PPC. AES Distributed Energy Contains Proprietary Information Page 8 of 18 Fire Control 1) Fire Suppression A Fire Suppression System with NOVEC 1230 is included in these containers. Although NFPA 2001 is intended for occupied buildings and this BESS container is not occupied, the design of the fire suppression system complies with the relevant parts of that standard. Cup burner tests on the electrolyte in the Samsung batteries resulted in a 5.6% Novec 1230 concentration to extinguish the fire. Even though other studies and actual events have shown that large scale lithium battery fires were not able to be put out by a clean agent fire suppression system, the suppression system in these containers will suppress a smaller fire from a non-battery source and prevent it from becoming a larger fire. 2) Explosion Control, NFPA 68 and 69 NFPA 69: Explosion Control There is no flammable gas released during the normal operation of the unit. Therefore, a continuous or intermittent ventilation system is not required, nor desirable. If several operational safety stops fail, and a hazard occurs that brings the batteries to exceed 160 °C, then thermal decomposition could occur, during which flammable gas could be released from the batteries. The first method for predicting a potential flammable gas condition checks for excessive battery temperature and voltage readings. This method is the most reliable. If excessive voltage and temperatures are detected by the rBMS, sBMS, or PCS controller, the system is automatically shut down, and AES operators are notified. As a secondary detection method, gas detectors for Hydrogen (H2), Carbon Monoxide, (CO), and/or methane (CH4), can be added and connected to an active exhaust system. Based on testing of the gases vented from a battery, these three have the highest fraction as shown in Table 1. When one of these flammable gasses are detected, the exhaust system activates. The exhaust system blows at about 3000 cfm, so for a 40’ HC container size enclosure, the turnover time is about 1 minute. Table 1. Measured Gas Composition of a Vented Cell (SDI Confidential Information) Gas Measured v/v% Component LFL Hydrogen 31.8% 4.0% Carbon Monoxide 19.4% 10% Methane 9.2% 4.4% Other Various HC Gasses* 11% ~2% Non-Flammable CO2 28.6% N/A *Various C2-C5 hydrocarbons released, but none > 5.5% and most > 1%. NFPA 68: Deflagration Venting Because the system has a flammable gas detection and active exhaust system, deflagration protection is not required. Even so, the calculations per NFPA 68 were calculated for informative purposes. AES Distributed Energy Contains Proprietary Information Page 9 of 18 Deflagration venting using the off-gassing data from Samsung’s UL9540A tests would require a rupture area of 14 m2 to prevent the internal pressure from rising above the safe requirements of a low strength structure (<0.5 bar-g rise). There are 105 meters of linear door seal area with a width of 2 cm (2 m2) that would also blow out in an explosive event. In an explosive event the pressure inside the container could reach 3.5 bar-g with the rupture vents and doors seals release according to high strength structure calculations. Such a deflagration event could only occur upon the failure of all four levels of protection that are in place. 3) Fire Spread and Exposures Containers are spaced a minimum of 8 feet from other electrical equipment, and at least 16 feet from any combustible materials. This separation reduces the likelihood that a fire originating in the battery container will spread to other equipment, or that fire originating outside the battery container will spread to the container. Fire Emergency Response First responders should not approach the container if there is a fire in the BESS. Fire control management should be restricted to protect property surrounding the site and prevent the fire from spreading beyond the site. AES will provide a Fire Mitigation Person in the event there is a fire. This person will be one of the AES operations members in the area and assigned to that site. AES Distributed Energy Contains Proprietary Information Page 10 of 18 Part 2. Fire Safety Analysis Based on NFPA 855 NFPA 855 is the newest Fire Code specifically written to address safety for large stationary battery systems. This assessment reviews NFPA 855 for the sections specific to the Hazard Analysis. Adherence to requirements of NFPA 855 regarding the general design, construction and operation are incorporated in the project design documents. Chapters 1, 2 and 3 are informative. Chapter 4 The design, construction, and operation of the system complies with the relevant sections of Chapter 4. Section 4.1 General and 4.14 Hazard Mitigation Analysis The General requirement in Section 4.1 have been followed for this system. The following responds to NFPA 855, Section 4.1.4 Hazard Mitigation Analysis. 4.1.4.1* A hazard mitigation analysis shall be provided to the AHJ for review and approval when any of the following conditions are present: (1) When technologies not specifically addressed in Table 1.3 are provided. (2) More than one ESS technology is provided in a room or indoor area where adverse interaction between the technologies is possible. (3) When allowed as a basis for increasing maximum stored energy as specified in 4.8.1 and 4.8.2. Items 1 and 2 do not apply. Item 3 applies as the Max Stored energy in Table 4.8 is 600 kWh and this project stores up to 4240 kWh in an enclosure. 4.1.4.2 The analysis shall evaluate the consequences of the following failure modes and others deemed necessary by the AHJ: (1) Thermal runaway condition in a single module, array, or unit (2) Failure of an energy storage management system (3) Failure of a required ventilation or exhaust system (4) Failure of a required smoke detection, fire detection, fire suppression, or gas detection system 4.1.4.2.1 Only single failure modes shall be considered for each mode given in 4.1.4.2. These 4 items have been included in the FMEA: 1) Thermal runaway conditions in a single module, array and rack have been evaluated and reported by Samsung in their UL 9540A report. In summary, it was found that off gassing of a cell occurs at temperature greater than 160 °C, thermal runaway occurs and temperature greater than 168 °C. A thermal runaway propagated to other cells in a single module but did not propagate to other modules. And, a thermal runaway in one rack did not propagate to another rack. There were no re- ignitions after the initial event and no flaming occurred during the test. Each cell can release up to 144L of gas during complete thermal decomposition. To reach the LFL (5.5%) during off-gassing, every cell in at least 1.3 modules would need to vent. AES Distributed Energy Contains Proprietary Information Page 11 of 18 2) A failure of power or communications of the BMS or PPC results in the automatic shut down of the system and disconnection of strings from the DC bus. This puts the system in a safe condition from electrical fires caused by faults, overcharging, or undercharging. a) The BMS protection map is found in Section 2 of the Samsung O&M Manual. b) The PPC protection map is found in the GPTech PPC Signal List, v0.5.1 or newer. 3) There is no continuous exhaust ventilation required for this system. A failure of the flammable gas detection and ventilation system could result in a combustible gas mixture in the enclosure, which could result in an explosion, ONLY IF THE FOLLOWING ADDITIONAL FAILURES TAKE PLACE: a) The PPC fails to detect and act on an over or undercharging condition; and b) The BMS fails to detect and act on an over or undercharging condition; and c) The PPC and BMS fail to detect cell temperatures that exceed the off-gassing limits; and d) A significant number of cells simultaneously reach the critical temperature for off gassing such that the Flammability Limits are reached; and e) An ignition source is available that initiates combustion of the gasses. The probability that all these failure events would occur is considered improbable and is not necessary to consider according to 4.1.4.2.1. One condition where such simultaneous failures could take place would be a large site fire that started externally and engulfed the battery enclosure, which is made unlikely through the separation from combustible materials. 4) The fire suppression system installed in the container is primarily to limit the possible spread of an electrical or other non-battery fire. The fire suppression system is monitored by the PPC, which will shut down the system if communication is lost or the fire suppression system triggers a system lockout as a result of an internal error. 4.1.4.3 The AHJ shall be permitted to approve the hazardous mitigation analysis as documentation of the safety of the ESS installation provided the consequences of the analysis demonstrate the following: (1) Fires will be contained within unoccupied ESS rooms for the minimum duration of the fire resistance rating specified in 4.3.6. (2) Suitable deflagration protection is provided where required. (3) ESS cabinets in occupied work centers allow occupants to safely evacuate in fire conditions. (4) Toxic and highly toxic gases released during normal charging, discharging, and operation will not exceed the PEL in the area where the ESS is contained. (5) Toxic and highly toxic gases released during fires and other fault conditions will not reach concentrations in excess of immediately dangerous to life or health (IDLH) level in the building or adjacent means of egress routes during the time deemed necessary to evacuate from that area. (6) Flammable gases released during charging, discharging, and normal operation will not exceed 25 percent of the LFL. 1) This requirement is not applicable as the BESS enclosure is not in the vicinity of any occupied building or structure. AES Distributed Energy Contains Proprietary Information Page 12 of 18 2) Deflagration protection is provided by prevention and detection of flammable gases, and finally the failure of the door seals and rupture vents. See the section below on deflagration analysis. 3) This requirement is not applicable as the BESS enclosure is unoccupied. 4) There are no toxic gases released during normal operation. 5) Since the enclosure is non-occupied, this section does not apply. The hazard was investigated for personnel that may be in the vicinity, external to the enclosure. During nail penetration tests, thermal off gassing and combustion of the Samsung batteries, there was minimal toxic gases produced, the most abundant being carbon monoxide as shown in Figure 2 and Figure 3. 6) There are no flammable gasses released during normal operation. Figure 2 – Gas evolved from two nail penetration tests of a Samsung Battery Cell (94Ah). Figure 3 – Gas evolved from thermal run-away tests of a Samsung Battery Cell (94Ah). 4.1.4.4 The hazard mitigation analysis shall be documented and made available to the AHJ and those authorized to design the operate the system. This report will be made available as required. 4.1.4.5* Construction, equipment, and systems that are required for the ESS to comply with the hazardous mitigation analysis shall be installed, tested, and maintained in accordance with this standard and the manufacturer's instructions. This requirement is met by the Quality Control procedure and documents as part of the system commissioning. The overall site Operations and Maintenance manual includes all necessary commissioning tests, which may be repeated from time to time to ensure ongoing safe operation of the system. Section 4.2 Equipment The section relates to the design and operation of the system. The system complies to the applicable requirements. Section 4.3 and 4.4 Installation Requirements and Location The BESS facilities assessed are considered Outdoor, Remote, and Non-occupied. As a result, many of the requirements in Section 4.3 and 4.4 do not apply Gas H2 CO CO2 CH4 C2H6 C2H4 C3H8 C3H6 C3H4 C4's C5's Sample 31.8% 19.4% 28.6% 9.2% 0.52% 5.5% 0.20% 3.4% 0.03% 1.3% 0.053% AES Distributed Energy Contains Proprietary Information Page 13 of 18 4.4.3.1 Remote outdoor locations include ESS located more than 100 ft (30.5 m) from buildings, lot lines that can be built upon, public ways, stored combustible materials, hazardous materials, high-piled stock, and other exposure hazards not associated with electrical grid infrastructure. Sections 4.5 4.6, 4.7, 4.8, & 4.9 Section 4.5 on Mobile systems does not apply. Section 4.6. Per 4.6.1, Size and Separation restrictions do not apply for this system. Section 4.7 Occupied Work Center restrictions does not apply. Section 4.8 Maximum stored energy restrictions do not apply. Section 4.9 Exhaust Ventilation does not apply. Section 4.10 Smoke and Fire Detection 4.10.1 All fire areas containing ESS systems located within buildings or structures shall be provided with a smoke detection system in accordance with NFPA 72. Smoke detectors are included in the design per NFPA 72 Sections 17.7. Section 4.11 Fire Control and Suppression Fire Suppression systems are not required for this system (outdoor, remote, non-walk-in) according to 4.11.1, as it is not required elsewhere in the standard. Chapter 9 requires thermal runaway mitigation, which can be addressed through other means. Section 4.11.4-9 specifically exempt several types of systems, namely 4.11.9: 4.11.9 When approved by the AHJ, ESS shall be permitted to be installed in outdoor walk-in enclosures without the protection of an automatic fire control and suppression system where large-scale fire testing conducted in accordance with 4.1.5 documents that an ESS fire does not compromise the means of egress and does not present an exposure hazard in accordance with 4.4.3.3 and 4.4.3.4. There seems to be a section missing that exempts outdoor non-walk-in enclosures, in which the hazard is significantly less. Although not required, the BESS system includes a clean-agent fire suppression system. Section 4.12 Explosion Control Explosion control is required from Chapter 9. Explosion Control involves 1) explosion prevention and 2) deflagration venting. 4.12.2 Explosion prevention and deflagration venting shall not be required where approved by the AHJ based on largescale fire testing in accordance with 4.1.5 that demonstrates that flammable gas concentrations in the room, building, or walk-in unit cannot exceed 25 percent of the LFL in locations where the gas is likely to accumulate. The BESS system addresses explosion control as described in Section 3 of Part 1 of this document. Section 4.13 Water Supply Water is not supplied for these systems, so requirements of NFPA 1142 apply. AES Distributed Energy Contains Proprietary Information Page 14 of 18 Sections 4.14, 4.15 Section 4.14 Spill Control does not apply to this system, as it does not employ a liquid electrolyte. Section 4.15 Neutralization does not apply to this system. Section 4.16 Remediation Measures 4.16.2.1 When, in the opinion of the AHJ, it is essential for public safety that trained personnel be on site to respond to possible ignition or reignition of damaged the ESS, the owner, agent, or lessee shall provide one or more fire mitigation personnel, as required and approved, at their expense. 4.16.2.2 These personnel shall remain on duty continuously after the fire department leaves the premises until the damaged ESS is removed from the premises or the AHJ indicates they can leave. 4.16.2.3 On-duty fire mitigation personnel shall have the following responsibilities: (1) Keep diligent watch for fires, obstructions to means of egress, and other hazards (2) Immediately contact the fire department if their assistance is needed to mitigate any hazards (3) Take prompt measures for remediation of hazards and extinguishment of fires that occur (4) Take prompt measures to assist in the evacuation of the public from the structures Section 4.16 specifies that AES is to provide trained personnel to respond and be on site in the event there is a fire. AES has an operations crew in the area for this purpose. Chapter 5. System Interconnections 5.1* General. All electrical connections and wiring to and from an ESS or the components of an ESS shall be in accordance with NFPA 70 or IEEE C2 based on the location of the ESS in relation to and its interaction with the electrical grid. The system design meets the specifications of Section 5 where applicable. Chapter 6, 7 & 8 Chapter 6 Commissioning, Chapter 7 on Operation and Maintenance, and Chapter 8 on Decommissioning does not contain material for the Hazard Analysis. These elements are addressed in the BESS O&M Manual. Chapter 9 Electrochemical Energy Storage Systems Chapter 9 specifies that Lithium-Ion ESS need compliance with thermal runaway, explosion control and size and separation, but do not need exhaust ventilation, spill control, neutralization, or safety caps. Chapters 10, 11, 12, 13, 14, & 15 These chapters do not apply to this system. AES Distributed Energy Contains Proprietary Information Page 15 of 18 Part 3. Fire Safety Analysis Based on NFPA 1 Chapter 52 Chapter 52 of NFPA 1 up until 2018 was a code addressing safety of battery systems in buildings, specifically for facility standby power, emergency power, or uninterrupted power supplies. The 2018 version was expanded to include stationary battery systems of all types; however, still heavily focused on batteries in or associated with occupied buildings, so most of this code is not applicable to this BESS project system. The requirements of NFPA 1 Chaper 52 are compatible, although less specific for this type of project, than the requirements in NFPA 855. The following addresses each part of Chapter 52. Section 52.1 General and 52.2 Permits Energy storage systems shall comply with Chapter 52. Permits, where required, shall comply with Section 1.12 of NFPA 1, which provides requirements for AHJ permitting. Section 52.2 PdAcid & NiCd, Section 52.3.3 Capacitors Lead-Acid, NiCd, and Capacitors – Not applicable to this project. Section 52.3.2.1 Location This section specifies requirements for outdoor, non-walk in systems to be in noncombustible enclosures that are locked and accessible only to authorized persons. The enclosure shall be separated from other buildings, lot lines by at least 5’; and separate from any means of egress from other buildings by 10’. Section 52.3.2.2 and 3 Max Allowable Quantities, Battery Arrays Section *.2 addresses batteries in occupied buildings or rooms and does not apply. In addition, the BESS system for this study has undergone a hazardous mitigation analysis and the battery system has large scale fire and fault testing performed (UL9540A) by the battery manufacturer. Per this section *.3, the BESS system studied here should be permitted to exceed the capacity limits of table 52.3.2.2.1 because a the system has undergone large-scale fire and fault conditions testing showing that a fire involving one array will not propagate to an adjacent array, and be contained within the room per 53.3.2.1.3 (which does not apply because it is for inhabited buildings). Section 52.3.2.4 Hazard Mitigation Analysis An FMEA has been performed for the BESS system studied in this report, and thus provides further allowance to increase the quantities specified in Tabel 52.3.2.2.1. Most of this section refers to occupied buildings, which is not applicable to this project. There are no toxic or flammable gasses released during charging, discharging, or normal operation. Equipment and Systems required to comply with the hazard mitigation analysis shall be installed, maintained, and tested per national standards. The BESS system studied here complies as all components of the safety systems are UL listed. Section 52.3.2.5 Listings The batteries in this BESS project are UL 1973 listed. The project system studied here is a custom design by Professional Engineers and sealed accordingly; it is not a prepackaged or pre-engineered system. The AES Distributed Energy Contains Proprietary Information Page 16 of 18 battery enclosure includes environmental control to meet conditions within the battery manufacturers specifications. Section 52.3.2.6 Installation The project system contains an advanced BMS and SCADA that addresses requirements of article *.1. The charger is the PCS, a UL listed pre-engineered component meeting article *.2. The battery system is protected from vehicle impacts per article *.3. There is no combustibles stored in the container, which meets article *.4. Signage for the project system is included in the design set and has been reviewed to meet article *.5. Sections 52.3.2.6. 6, 7 & 8. Seismic, Caps and Mixed Batteries. The project system is designed per seismic code. Vented caps are not required for Li-Ion systems. There are small Lead Acid back-up batteries for the controls and Fire Safety System in the enclosure with the Lithium Ion batteries, and there is no unsafe interaction between them. Section 52.3.2.7 Fire Suppression and Detection The project system is not a building or habitable room so an automatic sprinkler system is not required. The system contains a Clean Agent Fire Suppression system with a design based on NFPA 2001 (although that code is for habitable rooms, and so is not completely applicable) and fire and fault testing. The project system contains a Fire Safety System with detection, alarms and monitoring meeting article *.2. Section 52.3.2.8 & 9 Ventilation and Spill Control For the Project System, Ventilation is not required for lithium ion systems per 52.3.2.11.1. Spill Control and Neutralization is not require for Lithium ion systems per 52.3.2.11.1. Section 52.3.2.10 and 11 Thermal Runaway for Lithium Ion Batteries A device or method shall be provided to preclude, detect, and control thermal runaway is required per 52.3.2.11.1. The FMEA analysis and the accompanying Alarm and Protection tables for the SCADA, BMS, physical design and Fire Safety System describe this compliance. Section 52.3.2.12 Testing, Maintenance, and Repairs. This section states testing and maintenance shall be in accordance with the manufactures instructions, by which the compliance is explained in the project design and operation documentation. AES Distributed Energy Contains Proprietary Information Page 17 of 18 Definitions • BESS – Battery Energy Storage System – Overall system for storing electrical energy, including the battery modules, containers, power converters, controls, and protection devices. • BMS – Battery Management System – Controller responsible for management of the battery bank, including module-level data such as voltage and temperature, rack-level data such as min/max temperature and state of charge, and bank-level data such as # of racks connected, state of health, and alarms. • PLC – Programmable Logic Controller • PPC – Power Plant Controller – Controller responsible for closed-loop power control at the point of interconnection. Manages inverter and power converter power levels, and site-level alarms. • SOC – State of Charge – Current charge of the battery bank, from 0-100%. SOH – State of Health – Current battery capacity as a percentage of the beginning of life value. *Table A.5.2.5(a) of NFPA551 Severity Impact Negligible The impact of loss will be so minor that it would have no discernible effect on the facility, its operations, or the environment. Marginal The loss will have an impact on the facility, which may have to suspend some operations briefly. Some monetary investments may be necessary to restore the facility to full operations. Minor personal injury may be involved. The fire could cause localized environmental damage. Critical The loss will have a high impact on the facility, which may have to suspend operations. Significant monetary investments may be necessary to restore to fulfill operations. Personal injury and possibly deaths may be involved. The fire could cause significant reversible environmental damage. Catastrophic The fire will produce death or multiple deaths or injuries, or the impact on operations will be disastrous, resulting in long-term or permanent closing. The facility would cease to operate immediately after the fire occurred. The fire could cause significant irreversible environmental damage. *Table A.5.2.5(a) of NFPA551 Probability Description Frequent Likely to occur frequently, experienced (P>0.1) Probable Will occur several times during system life (P>0.001) Occasional Unlikely to occur in a given system operation (P>10-6) Remote So improbable, may be assumed this hazard will not be experienced (P<10-6) Improbable Probability of occurrence not distinguishable from zero (P ~ 0) Reference Documents Codes and Standards: AES Distributed Energy Contains Proprietary Information Page 18 of 18 • UL 9540 Energy Storage Systems and Equipment • UL 9540A Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems (BESSs) • UL 1973 Standard for Batteries for Use in Stationary, Vehicle Auxiliary Power and Light Electric Rail (LER) Applications • NFPA 1 Fire Code, Ch 52, Stationary Storage Battery Systems • NFPA 68 Explosion Protection by Deflagration Venting • NFPA 69 Explosion Prevention Systems • NFPA 70/NEC Article 706 • NFPA 550 Fire Safety Concepts Tree • NFPA 551 Evaluation of Fire Risk Assessments • NFPA 855 Stationary Energy Storage Systems • NFPA 2001 Clean Agent Fire Extinguishing Systems • IEEE/ASHRAE 1635 Guideline 21 Guide for the Ventilation and Thermal Management of Batteries for Stationary Applications • IFC Chapter 12 Energy Systems, Section 1206 Electrical Energy Storage Systems • FM Global Property Loss Prevention Data Sheet # 5-33, Electrical Energy Storage Systems Publications: • DOE OE Energy Storage Systems Safety Roadmap, PNNL-SA-126115, SAND2017-5140 R o Codes and Standards Update, March 2019, SNL. • Energy Storage Safety: 2016, EPRI, SAND2016-6297R Equipment Specific Information • Samsung O&M Manual • Samsung UL9540A report • GPTech Operations Manual • GPTech PPC Signals List • Notifier Fire Control Panel Manual • Siex Fire Suppression Design AES High Mesa Solar – Land Use Change – Major Impact permit application (10/22/2021) AES High Mesa Solar – Garfield County 58 Please see the following pages for the Garfield County Wildfire Susceptibility Map in the area of the AES High Mesa Solar project. GARFIELD COUNTY WILDFIRE SUSCEPTIBILITY MAP Appendix C10 Battlement MesaRulisonCarbonateN/CDE BEQUE FPDRIFLE FPDLOWER VALLEY N/CN/CGRAND VALLEY FPDBURNING MOUNTAINS FPDN/CN/CGYPSUM FPDGLENWOOD SPRINGS FDCARBONDALE AND RURAL FPDN/CN/CN/CN/CRifleSiltGlenwood SpringsNew CastleCarbondaleParachute§¨¦70§¨¦70§¨¦70UV13UV139UV82UV6UV325UV133£¤6£¤6£¤6T2NT5ST1NT2ST1ST5ST4ST6ST7SR93WR91WR99WR96WR89WR97WR90WR92WR88WR98WR101WR102WR95WR103WR104WR94WR100WR105W107°5'W107°5'W107°10'W107°10'W107°15'W107°15'W107°20'W107°20'W107°25'W107°25'W107°30'W107°30'W107°35'W107°35'W107°40'W107°40'W107°45'W107°45'W107°50'W107°50'W107°55'W107°55'W108°0'W108°0'W108°5'W108°5'W108°10'W108°10'W108°15'W108°15'W108°20'W108°20'W108°25'W108°25'W108°30'W108°30'W108°35'W108°35'W108°40'W108°40'W108°45'W108°45'W108°50'W108°50'W108°55'W108°55'W109°0'W109°0'W40°10'N40°10'N40°5'N40°5'N40°0'N40°0'N39°55'N39°55'N39°50'N39°50'N39°45'N39°45'N39°40'N39°40'N39°35'N39°35'N39°30'N39°30'N39°25'N39°25'N39°20'N39°20'N39°15'N39°15'N$WeldMoffatMesaBacaParkRouttYumaLas AnimasGarfieldLincolnLarimerPuebloGunnisonBentElbertSaguacheGrandRio BlancoLoganEagleKiowaEl PasoMontroseOteroDeltaWashingtonLa PlataKit CarsonProwersJacksonFremontPitkinMontezumaCheyenneHuerfanoMorganAdamsCostillaConejosArchuletaDoloresChaffeeHinsdaleMineralSan MiguelCusterTellerDouglasCrowleyPhillipsBoulderOurayAlamosaArapahoeSummitRio GrandeLakeSedgwickJeffersonSan JuanClear CreekGilpinDenverBroomfieldUta hUta hKansasK a ns asWyomingWyomingNew MexicoNew MexicoNebraskaNebraskaOklahomaOklahomaGarfield County Community Wildfire Protection PlanMap 7: Wildland Fire Susceptibility IndexGarfield County, CONAD83 UTM Zone 13NU:\Projects\901162_0001_010_GarfieldCWPP\map_mxd\GarfieldCWPP_WildfireSusceptibility_ANSID.mxd 9/25/2012010MilesUtility LinesRailroadsCounty Roads - GarfieldLocal Roads - GarfieldInterstate-ExpresswayHighwayStreamsTownshipsCity LimitsFire Districts (N/C = Not Covered)Wildland Urban InterfaceLakes-ReservoirsWildland Fire Susceptibility IndexNR240,661 AcresLow1,194,700 AcresModerate246,396 AcresHigh145,838 AcresVery High65,790 AcresSource: CSFS AES High Mesa Solar – Land Use Change – Major Impact permit application (10/22/2021) AES High Mesa Solar – Garfield County 59 Please see the following pages for the Geotechnical Engineering Report performed for AES High Mesa Solar, LLC in February 2021. GEOTECHNICAL ENGINEERING REPORT Appendix C11 REPORT COVER PAGE DRAFT - Geotechnical Engineering Report __________________________________________________________________________ Holy Cross Solar Project – High Mesa Site 1691 County Road 300 Parachute, Colorado February 19, 2021 Terracon Project No. 25205263B Prepared for: HDR Engineering, Inc. Denver, Colorado Prepared by: Terracon Consultants, Inc. Denver, Colorado Terracon Consultants, Inc. 10625 W I -70 Frontage Rd N, Ste 3 Denver , Col orado 8 0033 P (303) 423 -3300 F (303) 423 -3353 terracon.com REPORT COVER LETTER TO SIGN February 19, 2021 HDR Engineering, Inc. 1670 Broadway, Suite 3400 Denver, Colorado 80202 Attn: Mr. Dave Phillips P: (303) 323-9805 E: dave.phillips@hdrinc.com Re: DRAFT - Geotechnical Engineering Report Holy Cross Solar Project – High Mesa Site 1691 County Road 3001 Parachute, Colorado Terracon Project No. 25205263B Dear Mr. Phillips: We have completed the DRAFT - Geotechnical Engineering services for the above referenced project. This study was performed in general accordance with Terracon Proposal No. P25205263 dated August 12, 2020. This report presents the findings of the subsurface exploration and provides geotechnical recommendations concerning earthwork and the design and construction of foundations and unpaved access roads for the proposed project. We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report or if we may be of further service, please contact us. Sincerely, Terracon Consultants, Inc. DRAFT DRAFT Nick M. Novotny, P.G., C.E.G. Scott B. Myers, P.E. Senior Staff Geologist Regional Senior Consultant Subject Matter Expert Reviewed By: F. Fred Buhamdan, P.E. (CA)