J.26 FAA-E-99001 - Photovoltaic Specification.pdf

FAA-E-99001

FAA-E-99001

MARCH 2018

DEPARTMENT OF TRANSPORTATION

FEDERAL AVIATION ADMINISTRATION

SPECIFICATION

PHOTOVOLTAIC SPECIFICATION

This specification is approved for use by all Departments of the Federal Aviation Administration (FAA)

FAA-E-99011

Change History

1. Originator Name and Address AJW-222, Power Services Group

2. Proposed 3. Code Identification 4. Document No. FAA-E- 99001

Oklahoma City, OK

[X] Approved 5. Code Identification 6. DCN No.

7. System Designation 8. Related ECR/NCP No. 9. Contract No. 10. Contractual Activity N/A

11. Product Integration Plan 12. Effectivity

This notice informs recipients that the standard identified by the number (and revision letter) shown in block 4 has been changed. The pages changed by this DCN (being those furnished herewith) carry the same date as the DCN. The page numbers and dates listed below in the summary of changed pages, combined with non-listed pages of the original issue of the revision shown in block 4, constitute the current version of this specification.

13. DCN

No. 14. Pages changed S* A/D* 15. Date

1 SCOPE

This specification covers photovoltaic equipment installed in the FAA. This includes both NAS and non-NAS photovoltaic equipment. Photovoltaic equipment includes: photovoltaic panels, inverters, charge controllers, and all balance of system equipment.

2 APPLICABLE DOCUMENTS AND INDUSTRY STANDARDS

2.1 Federal Aviation Administration (FAA) Standards (Latest version) FAA-STD-1217: Electrical Work, Interior

FED-STD-019: Lightning And Surge Protection, Grounding, Bonding And Shielding Requirements For Facilities And Electronic Equipment

FAA-G-2100H: Electronic Equipment, General Requirements

FAA-E-1391: Installation, Termination, Splicing, And Transient/Surge Protection Of Underground Electrical Distribution System Power Cables

FAA 3900.19B: Occupational Safety and Health Program

Copies of FAA Standards may be obtained from:

Federal Aviation Administration NAS Documentation Control Center 800 Independence Avenue, SW Room 700W, AJW-261 Washington, DC 20591 Phone: (202) 600-7544 Fax: (202) 600-7524

Copies of Military Standards and Specification Publications may be obtained from:

DODSSP

Building 4, Section D 700 Robins Avenue Philadelphia, PA 19111-5094 Phone: (215) 697-6396 Fax: (215) 697-9398 http://quicksearch.dla.mil/

2.2 Non-Government Documents (Latest version)

• IEEE 1547: Standard for Interconnecting Distributed Resources with Electric Power Systems

• UL 1741: Standard for Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources

• IEEE 519: Recommended Practice and Requirements for Harmonic Control in Electric Power Systems

• IEEE 1562: Guide for Array and Battery Sizing in Stand-Alone Photovoltaic (PV) Systems http://quicksearch.dla.mil/

• TROV-2 OF HAWAI’I PUBLIC UTILITIES COMMISION(HECO) : Transient Over-Voltage and Frequency Requirements for Inverter-Based Distributed Energy Resources

• Title 47 CFR PART 15: Rules and Regulations for Radio Frequency Devices NFPA 780: Standard for the Installation of Lightning Protection Systems

• DOE NREL/TP-5D00-63510: Inverter Load Rejection Overvoltage Testing

• Sunspec Alliance: Communications Modbus Protocol

• DOE FEMP: Procurement Specifications Templates for Onsite Solar Photovoltaic

• NFPA 70, National Electric Code

2.3 Precedence of Documents

In the event of a conflict between the above-mentioned documents and this specification, this specification shall govern.

3 Definitions A:L ratio - ratio of PV array generated daily average energy in kilowatt-hours (A for Array) to daily average load of equipment in kilowatt-hours (L).

Active PV module – a PV module that makes use of active components (typically diodes) to attempt to regulate the output voltage/current of the module

Bi-Directional Inverter – An inverter that can operate as both an inverter and a rectifier depending on the direction of power flow. Frequently found with battery systems.

Central Inverter – a large PV inverter that typically is not paralleled to any other inverters.

Typically larger than 100 kVA.

Charge Controller - DC-to-DC converters that optimize and regulate the DC power out of PV systems. These are primarily used in battery charging applications. They control the flow of current into the batteries and prevent overcharging of batteries.

Combiner Box – devices that combine several PV modules. These are typically used for paralleling PV modules. Most common in central inverter applications

Grid-Tie inverter – a PV inverter that is designed to be connected to the utility grid. These are not capable of operating without utility power.

HECO – Hawai’ian Electric Coop. Hawaii has a significant amount of PV power and a great deal of experience dealing with the side effects of dealing with this high rate of penetration. The state of Hawaii and their utility companies have adopted many requirements that are now being used as industry standards. California has also passed similar requirements, such as “Rule 21”.

Hybrid inverter – a PV inverter that is designed to operate in either a grid-tie or an off-grid mode. These are also referred to as “multi-mode” inverters. Hybrid inverters have both “grid-tie” and “off-grid” elements. Hybrid inverters must meet the requirements for both systems.

Micro-inverter – a small sized inverter that is designed to be installed directly to a panel and only invert the power from the individual panel.

Net Zero Systems – systems which generate equal (kWh) in a year to what the facility consumes. The power output of the PV component of a “net zero system” is typically 4-6x larger than the average demand of the facility

Off-grid inverter – a PV inverter that is designed to operate without any utility grid. These are capable of operating without utility power.

Passive PV module- a PV module that does not use any internal active components. It is simply photovoltaic cells.

Photovoltaic (PV) cell- equipment capable of producing a voltage when exposed to light

Photovoltaic (PV) module – a packaged array of photovoltaic cells. Also referred to as a “panel”

String Inverter – a medium sized inverter that is designed to parallel with other string inverters and the utility grid. Typically 10-100 kVA.

TrOV – Transient OverVoltage. This is a power anomaly that is defined as brief changes to the nominal voltage waveform. These have been observed during the shutdown of inverters for a myriad of reasons. If they are large enough, they can cause damage to equipment.

4 REQUIREMENTS

4.1 General

The orders, standards, rules, regulations, and reference specifications enumerated herein are considered as minimum requirements. FAA requirements often exceed those of other standards organizations such as the NFPA. Adherence to other standards does not relieve contractors from furnishing and installing higher grades of materials and workmanship required by this standard.

Facility design and construction standards for specific NAS facilities may have detailed requirements for use of particular wiring methods. This standard for general electrical work at FAA facilities does not supersede any facility-specific standard. In no event shall electrical codes be violated.

Unscheduled interruptions of the electrical service to FAA facilities may cause aircraft accidents and loss of life. Work requiring a temporary or permanent energizing and/or de-energizing of equipment shall be scheduled in writing with the onsite FAA maintenance personnel. Only onsite FAA maintenance personnel are authorized to energize equipment, de-energize equipment or to operate a circuit breaker, switch, or fuse in FAA facilities. Work procedures shall include lock-out/tag-out procedures in accordance with FAA Order 3900.64 and NFPA 70E.

FAA installations shall meet or exceed the requirements of NFPA 70, National Electric Code.

4.2 Equipment

Same Manufacturer and Product Line All modules are to be of same manufacturer and product line for each array, all inverters are to be of same manufacturer and product line for each array, all electrical switchgear are to be of same manufacturer and product line for each array, and all module rack mounting shall be of same manufacturer and product line for each array.

Site Service Conditions Materials shall be designed to withstand the year-round temperatures and conditions to which they are exposed (sunlight, heat, rain, cold, wind, seismic, salt air, fog, marine corrosiveness, etc.).

Corrosion Resistance All PV hardware and rack components shall be of corrosion-resistant material, such as stainless steel, aluminum, or hot-dipped galvanized steel.

Locating Equipment and Appearance Major electrical components, including the inverter, isolation transformer, and metering, shall be installed in code-compliant enclosures. Components shall be located indoors whenever feasible, in ventilated (non-air conditioned) utility rooms and where space and codes allow.

When inverters and major electrical components are located outdoors they shall be protected from direct exposure to weather (sun, rain, snow, and sleet). A simple open-sided shed roof structure is sufficient, as is a location under shaded carport arrays. Inverters shall not be located on roofs in direct sun.

Marking (Labeling) Best Practices Strict conformance to system marking (or labeling) requirements of PV systems and their components are crucial for the safety of operators, service personnel, emergency responders, and others. General PV system labeling requirements, as per NEC 2014 690 Ch. VI, and specific requirements from Articles 690 and 705, shall be followed. Include all required and desired labeling language in the design drawings for agency review.

Electrical equipment and components used in PV systems shall have markings that identify the manufacturer, size, type, ratings, hazard warnings, and other specifications. Equipment markings should never be removed, and all equipment markings must be durable for the environment in which the equipment is installed. Markings must be visible or easily accessible during and after installation.

All markings, whether applied in the factory or the field, shall be designed to withstand the environment in which they are installed (e.g., “UV rated” for outdoor labels) and permanently affixed to the respective equipment in a manner appropriate for the environment and compatible with the substrate materials. Field-applied markings are required on many types of equipment and components, including (but not limited to) conductors, connectors, conduits, disconnecting means, and point-of-utility connections, as are special markings for bi-polar arrays, ungrounded arrays, battery storage systems, stand-alone inverters providing a single 120-volt supply, and other marking as required by local codes.

Expected Service Life Unless noted otherwise, all materials for PV projects shall have an expected service life of thirty years (30) or more. Equipment warranties (modules, inverters, switchgear) are shorter than the expected service life. With a 30-year system life, it is common and well understood by industry that inverters and a small percentage of failed modules would need to be replaced though the system as a whole would provide at least 30 years of service.

4.2.1 Inverters

Inverters will meet Title 47 CFR PART 15 Class B requirements. This requirement is due to the sensitive nature of FAA facilities.

FAA frequently uses 3-wire distribution systems. Inverters shall be wired with a 4-wire (neutral) when connected to the utility transformer or a disconnect unless otherwise specified

4.2.1.1 Grid-Tie Inverters

Grid-tied systems will use string inverters unless otherwise specified.

Micro-inverters are not allowed at NAS facilities.

Inverters will meet, at a minimum, the TRoV-2 requirements established by HECO.

Manufacturers shall either have previously met this certification and be able to provide documentation or new testing must be conducted to the NREL testing requirements as specified by NREL/TP-5D00-63510

The TRoV-2 requirement is a maximum surge tolerance, similar to the ITIC curve. This requirement is meant to minimize voltage surges introduced to the grid during mandatory shutdown of the inverters, which occurs during power outages.

4.2.1.2 Off-grid Inverters

Off-grid inverters should be from a manufacturer with at least 10 years of experience in the electrical industry. Off-grid inverters are required to interface with currently contracted generator or with a common off-the-shelf (COTS) computer controller unless otherwise specified.

Manufacturer must provide standardized firmware and model numbers.

4.2.1.3 Bi-directional inverters

If the bi-directional inverter will deployed in a configuration where the inverter will be paralleled with engine generators, interoperability with currently contracted generator or with a common off-the-shelf (COTS) computer controller must be demonstrated prior to acceptance.

If being used in an off-grid application, manufacturer must provide standardized firmware and model numbers.

4.2.2 PV Modules

Photovoltaic modules shall be passive-type panels. Modules should be aluminum framed, unless otherwise specified. Modules should be wind-rated to minimum of 120 mph.

For all installations, a Structural Engineer should study the proposed array design, including wind load, ice/snow load, soil foundation or roof support requirements for the identified installation location and conditions.

Note: Higher wind speed ratings may be required in some areas. This is a design consideration not discussed in this specification

4.2.3 Panelboards

AC panelboards used for PV inverter aggregation are not different from typical AC panelboards, however those installed outside must meet the following requirements:

• Panelboards should be outdoor rated (NEMA 3)

• Outdoor panelboards do not require hinged covers

• If PV is part of covered parking, panelboard should be mounted to avoid interference with walking path and vehicles.

4.2.4 Charge Controllers

Charge controllers should be Maximum Power Point Tracking (MPPT) technology.

4.3 Design and Construction

4.3.1 General

Photovoltaic installations must meet the requirements of all relevant FAA electrical policy.

Standalone photovoltaic installations, where panels are mounted on purpose-built supports do not constitute a new roof or dwelling. Therefore, FAA/NFPA/NEC requirements for roofs, buildings, etc. do not apply to these standalone PV installations. The requirements that apply are those specific to PV or those that apply to outdoor installations.

4.3.2 Point of Interconnection

Point of interconnection is the physical location where the PV system interfaces with the utility power system. The term “point of interconnection” only applies to grid interactive systems and is not applicable for grid isolated systems.

All projects will make connections as high in the topology as possible (e.g. A rather than B).

4.3.2.1 Designated Connection Points

4.3.2.1.1 Interconnection Point A

Interconnection point A is defined as any interconnection that is made upstream of a dedicated utility transformer supplying power to the FAA facility. This could be made at a different physical location from the FAA Facility or it could be an additional transformer co-located at the FAA facility. The distinction is that the interconnection point is completely isolated from the FAA’s low-voltage (277/480V or 120/208V) distribution.

4.3.2.1.2 Interconnection Point B

Interconnection point B is defined as an interconnection that is made downstream of the utility transformer and upstream of the meter. This is most typically performed as an additional/separate connection on the secondary side of the utility transformer.

4.3.2.1.3 Interconnection Point C

Interconnection point C is defined as an interconnection that is made downstream of the utility transformer/meter and upstream of the main disconnect breaker of a facility. Example: On the line side of the facility’s main disconnect breaker.

4.3.2.1.4 Interconnection Point D

Interconnection point D is defined as an interconnection that is made downstream of the facility service main, on the main distribution bus of the facility. This connection is still upstream of any automatic switchgear (ATS or similar) or UPS equipment.

4.3.2.1.5 Integrated PV

NAS systems may have PV integrated into the system at many different levels, however, no PV system is allowed to supply power back to the utility company at any other point than those listed. All other PV systems must be islanded from utility power.

4.3.2.2 NEC Designations

The National Electric Code(NEC 705.10) defines two interconnection points:

Supply Side connection: Any connection made on the supply(line) side of the service disconnecting means. Interconnection B and C are Supply Side connections.

Load Side Connection: Any connection made on the load side of the service disconnecting means. Interconnection D is a Load Side connection.

4.3.2.3 Interconnection Point

All designs and installations shall receive formal approval through the NCP process.

Interconnections at Point B and C require additional approval as they will impact operations of the facility. Therefore, the installation must update all facility operation instructions. This includes providing updates to the following documentation:

• Technical Instruction Books

• Maintenance Handbooks

• Standard Operating Procedures

• Training

• Lock-out Tag-out

Interconnections made at point D are not allowed without approval from the OPR.

4.3.3 Interconnection Agreements

FAA Requirements Interconnection agreements must be approved by FAA legal representative and by the Power Services Group. Approval by other FAA stakeholders will also be necessary.

The following items are typical for Interconnection Agreements:

• Power Quality Standards-these are frequently identical or less stringent than the standards of IEEE 1547

• Shutdown requirement for PV inverters-these are frequently identical or less stringent than the standards of IEEE 1547

• IEEE 1547 compliance requirements

• UL 1741 compliance requirement

The following should not be included on Interconnection Agreement:

• Shutdown of electrical power to FAA facilities without prior coordination under any circumstances.

• Protective relaying requirements o The inverter provides internal monitoring and shutdown and is validated to UL 1741. External relaying requirements are common for diesel generator interconnection agreements and should not be included in PV interconnection agreements.

o Any additional relays installed should be utility owned and maintained, such as directional flow relays.

• Requirements which impose a financial penalty on the FAA for power quality issues

Non-FAA requirements Interconnection agreements are contracts between the FAA facility and the local utility/service provider. These requirements vary by city, region, state, and servicing utility. This document cannot capture all requirements. The following items may be included and require special attention:

• Interconnections may require changes to FAA standard operating procedures, which must be approved via an NCP before the PV system can be placed into service.

o All changes to configuration managed systems require an NCP o Changes to Lock-out/Tag-Out Procedures require updates to LOTO procedures in accordance with FAA 3900.19B

• Interconnection agreements may impose additional monitoring requirements on FAA facilities.

• Interconnection agreements may require extensive coordination of shutdown of the facility for testing of UL 1741 compliance of PV inverters. All activity must be properly coordinated and proper Operational Risk Mitigation processes must be followed.

4.3.4 Arc Flash

Arc Flash analysis for PV1 systems shall be done according to NFPA 70E and FAA 6950.27A requirements. All new circuits require arc flash analysis and arc flash labels.

4.3.4.1 Array Arc and Ground Fault Detection and Prevention

Hardware shall be included to detect DC ground and arc faults. Once faults are detected, automatic system shutdown must occur.

4.3.4.2 Acceptable Array Ground and Arc Fault Hardware Detection Schemes

• An arc-fault detection system which is listed by OSHA’s Nationally Recognized Testing Laboratory (NRTL) and compliant to the 2017 National Electrical Code must be installed. If a fault occurs, the system must shut down and send an automated alarm

• The PV system must include string-level DC residual current detector(s) (RCDs) that disconnect faulted circuit(s) and transmit an alarm

1 The contribution of fault current from PV systems is atypical for electrical equipment. Many PV inverters do not use transformers and do not have batteries. Fault current calculations are significantly different from batteries and other DC sources. Consult manufacturer and NFPA for more information on modeling the equipment.

4.3.4.3 Updates to Facility Arc Flash Study

New PV installations may not require updated arc flash studies for the entire facility. If the PV system’s rated power is less than 100% of the facility’s existing utility transformer KVA rating, no new arc flash study is required for the facility.

Installations at Interconnection Point A never require a new Arc Flash Study.

4.3.4.4 New Coordination Study

If the PV system is smaller than 250 kw(dc), then the project may be considered non-major for the purposes of FAA 6950.27 and no new coordination study is required for the facility.

4.3.4.4.1 Distributed Generation

Distributed Generation (such as PV string inverter) systems are not loads, and coordination of breakers within a distributed generation system may be unachievable.

4.3.5 Panel Arrangement

Ground mounted panels must be arranged so that emergency and maintenance vehicles can pass between the structures for fire and life safety purposes.

If panels are mounted on parking structures, structure and panel design must account for emergency vehicle access to adjacent buildings and must not block fire lanes or similar.

4.3.6 Net Zero Systems

Net Zero Systems have special safety and operational concerns.

The Power Services Group does not recommend the integration of such systems with operational NAS electrical infrastructure. Net Zero System PV should be installed on a separate utility transformer and isolated from the operational environment.

Net Zero Systems that share a common transformer with NAS critical loads requires PSG approval of Arc Flash and the facility Coordination Study prior to commissioning.

4.3.7 Security

Cyber Security All equipment to be installed at Government sites may be subject to cyber security screening to ensure that no security vulnerabilities are exposed or data breaches are created.

Preventing Vandalism and Theft PV installations are frequently a target for theft and vandalism. If the installation is at a remote facility or risk is high, consider the following:

• An appropriate fencing system with locked gates

• Lighting

• Security cameras

• Security patrols

• Motion-activated alarms and lighting

• Tamper-proof fasteners on arrays and cabinet fasteners

• Inverters, combiners, and main electrical switches locked with high-security padlocks

• Anti-theft devices for copper cabling

Fire Lanes Fire lanes established to access any adjacent facility by local fire department shall be maintained and comply with state, county, and local Fire guidance. Changes to fire lanes are allowed, but only under approval by Fire authorities having jurisdiction over the site and under coordination and approval by the FAA project manager.

4.4 Performance

4.4.1 Communications Protocol

All digital communications of performance data shall use the SunSpec Alliance convention for inter-compatibility of data.

4.4.2 Grid-Tie System Sizing

PV systems that are grid-interactive shall not be designed to generate more power during peak production than the annual average load of the facility (as measured per IEEE 519).

4.4.3 Off-Grid (Islanded) Design specification

Facilities, which are designed to operate without utility power, should be designed according to

IEEE 1562.

4.4.3.1 NAS Critical Loads

All PV systems that replace standby generators or provide prime power for NAS are considered off-grid applications, even if the NAS system has utility power as part of the design.

4.4.3.1.1 A:L ratio

A:L shall be 1.3 or greater for NAS critical off-grid systems, unless otherwise specified

4.4.3.1.2 Battery sizing

Battery capacity (kWh), unless otherwise specified:

• Ten3 days for lead-acid batteries

• Three days of warrantied capacity2 for all other battery technologies

4.4.3.1.3 Standby generators

Standby generators can be used to augment the capacity of batteries in an off-grid system. The design of generator+battery off-grid systems is complex and must be validated by a designer with experience in off-grid PV design.

4.4.3.2 Design for all other applications

2 Warrantied Capacity is the available capacity of the battery that the manufacturer will still provide 5-year warranty for the battery if the battery is cycled to this depth of discharge.

4.4.3.2.1 A:L ratio

A:L ratio shall be 1 or greater, unless otherwise specified

4.4.3.2.2 Battery sizing:

Battery capacity (kWh), unless otherwise specified:

• Three3 days for lead-acid batteries

• 24 hours of warrantied capacity2 for all other battery technologies

3 This capacity is intended to limit discharge depth, however, there are several emerging battery technologies which allow deeper discharge depths without severely impacting battery life

5 QUALITY ASSURANCE PROVISIONS

5.1 Qualification Procedures

All inspections and tests specified herein shall be performed at the Contractor’s plant. Unless otherwise specified, all documentation shall be made available to the government.

5.2 Title 47 CFR PART 15 Class B Compliance

The procedures proposed shall be sufficiently comprehensive and submittals shall be sufficiently detailed to ensure compliance by FAA reviewers. The Government reserves the right to require any additional tests necessary to assure that all the specification requirements are checked.

5.3 Department of Energy Procurement Specifications

The Department of Energy document: “Procurement Specifications Templates for Onsite Solar Photovoltaic” should be used to develop all PV contracts.

5.4 Contractor Qualifications

PV installation contractors must be certified by the following organization:

North American Board of Certified Energy Practitioners, Inc. (NABCEP®)

56 Clifton Country Road, Suite 202

Clifton Park, NY, 12065 www.nabcep.org

Phone: (800) 654-0021