A06_-_System_details.pdf

Maintenance Report:

Southeast Farallon Island

PV Power System

Conducted April – 2022

Nexgen Energy Systems, Inc., 2900 29th Ave SW, Suite B, Tumwater, WA 98512

360 357 1131 Ext 102 | NexgenES.com | Mike.McGoey@NexgenES.com | CA Contactor # 861277

Overview of maintenance performed on the

PV power system with recommendations for additional repairs.

Updated: 12/12/2022

360 357 1131 Ext 102 | NexgenES.com | Mike.McGoey@NexgenES.com | CA Contactor # 861277

Table of Contents Overview

Maintenance & Repairs Summary Table

1. PV Array Conduits and Supports

2. PV Array Electrical Equipment Ground

3. PV Array Wiring

4. PV Array Support Attachment Seals

5. PV Array Bird Spikes

6. PV Module Cleaning

7. PV Array Curve Trace Testing

8. Battery Seismic Support System

9. Battery Hazmat Containment

10. Battery Bank Connections

11. Battery Bank Condition

12. PV Charge Controller System

13. Generator Battery PV Charging Module

14. Battery Monitoring System

15. Remote Power Monitoring System

16. Firmware Updates & Fault Logs

17. Three-phase Generator System Troubleshooting .. 10

18. Three-phase Water Pumping System

19. East Landing Crane Control Cabinet

I. Appendix

Overview This report was written by Nexgen Energy Systems, Inc (NESI) for the U.S. Fish & Wildlife Service and Point Blue

Conservation Science regarding the Southeast Farallon Island (the island).

In April of 2022 NESI technicians traveled to the island to perform various maintenance tasks and assess the overall energy system.

It should be noted that while routine maintenance was performed on the system, there are areas that will require additional repair and maintenance in the future.

Maintenance & Repairs Summary Table

# Item: Completed: Priority:

1 Array Conduits & Supports No Medium

2 Equipment ground configuration No High

3 PV Conductor support Yes NA

4 Array Support Seals No High

5 Bird Spikes No Medium

6 PV Array Cleaning Yes High during peak season

7 PV Array Performance – IV Curve Yes Low

8 Battery Support System No High

9 Battery Hazmat Containment No High

10 Battery Bank Connections Yes NA

11 Battery Maintenance Yes High

12 Charge Controller Re-installation No High

13 Generator Battery PV Module Yes NA

14 Battery System Monitor No Medium

15 Remote Communications System Yes Medium

16 Firmware Updates & Fault Logs Yes Medium

17 Water Pumping System Yes Medium

18 Crane Cabinet Interlock Yes NA

360 357 1131 Ext 102 | NexgenES.com | Mike.McGoey@NexgenES.com | CA Contactor # 861277

1. PV Array Conduits and Supports

Item:

The PV system circuits on the roof are protected by conduit which are mechanically supported above the roofing membrane. The conduits enclose circuits between the array combiner boxes and the central power system within the powerhouse.

Findings:

1. Roof top conduit support components are showing evidence of rust and corrosion.

Solution:

Not resolved.

Recommendation:

1. Replace corroding components with stainless components.

a. Medium priority.

i. Corroded components are functional, but inevitably fail in the future.

Corrosion, oxidation, and degradation of metallic components occur more rapidly on the island due to its marine environment. To reduce the rate at which components corrode, they should be comprised of stainless steel.

2. PV Array Electrical Equipment Ground

Item:

The rooftop electrical equipment including PV modules, rails, and combiner boxes should all be connected with a common grounding circuit.

1. Most electrical components on the roof are not properly grounded.

a. Modules and rails have a separate ground from that of the combiner boxes.

i. The module and rail ground passes down the side of the building to the main ground rod.

ii. The combiner boxes ground passes down into the building and equipment room then to the main ground rod.

b. PV support rail ground connection points currently exhibit signs of corrosion.

c. The combiner boxes have a ground terminated within them but are not grounded because there is no connection to the central electrical system.

Conduit clap and screw are completely rusted.

Note: All metal components are steel, however the arrow indicates a stainless component that is not corroding.

Conduit clamps, screws, and strut are rusting.

360 357 1131 Ext 102 | NexgenES.com | Mike.McGoey@NexgenES.com | CA Contactor # 861277

Current situation:

Future Recommendation:

1. The electrical components on the roof should be properly grounded through the combiner boxes and the corroding ground components should be eliminated.

a. High priority.

Circuit breakers and other safety features require a common reference to ground in order to function properly.

2. Replace corroded rail ground points with bronze components.

a. High priority.

Combiner boxes have no reference to ground.

3. The combiner box should be integrated into the grounding system.

3. PV Array Wiring

The PV module conductors running behind the array should be secured and supported to prevent damage from wind induced movement.

1. Most of the PV conductors were loose and not properly secured.

Resolved by NESI, April 2022.

A support system was installed the length of each row to provide a secure and accessible attachment point for the

PV conductors. PV conductors had their attachments reinforced and are properly secure.

The issue has been resolved.

Array ground lug with signs of oxidization.

NOTE: The rail and ground lug are aluminum, however the rail is anodized and has no signs of corrosion.

Combiner box with ground wire in an isolated plastic termination.

Array with loose

PV conductor wires.

Array with PV conductor wires securely attached to support wire spanning the length of each row.

360 357 1131 Ext 102 | NexgenES.com | Mike.McGoey@NexgenES.com | CA Contactor # 861277

4. PV Array Support Attachment Seals

Item:

The solar PV array is supported by pedestals attached to the roof. These supports are sealed with membrane coating, clamps, and silicone caulking.

1. Most of the array support pedestals are not properly sealed against rain and salt spray.

a. The support seals are original and were not repaired or upgraded when the array was upgraded.

b. Many supports have their clamps fully exposed with little to no silicone caulking remaining.

Temporarily resolved by NESI, April 2022.

Several support seals in the worst condition received emergency repairs of new silicone caulking.

1. Repair all support seals with new, weatherproof, EPDM boots installed over the exposed pedestals and clamps. This solution would eliminate the need to continuously repair the silicone caulking.

a. High priority.

i. The faulty seals will lead to water penetration and damage to the PV array roof anchors and structure.

5. PV Array Bird Spikes

Bird spikes have been installed along the upper edge of the PV modules to prevent birds from roosting on the solar array.

1. Most of the existing bird spikes are damaged and broken.

a. Aa of the components are from the original installation and were not upgraded when the PV array was upgraded.

b. The plastic spike bases have become brittle and are broken in many places.

c. The metal spikes are bent and deformed in numerous locations.

d. The attachment screws are showing signs of rust.

Support seal with fully exposed metal pipe clamp.

Support seal with partially exposed metal pipe clamp.

1. Replace all the bird spikes with new stainless-steel components.

a. Medium priority.

i. Components are marginally functional but are severely damaged.

6. PV Module Cleaning

Item:

The modules comprising the PV array require clean glass surfaces in order to produce electrical energy efficiently.

Over time, the modules become soiled with bird droppings which results in reduced energy production.

1. The PV array had moderate soiling from a combination of bird droppings, and other debris.

Solution:

The PV array was washed and cleaned.

1. Wash the array regularly during periods of heavy soiling to maintain energy production and promote array component longevity.

a. High priority.

7. PV Array Curve Trace Testing

Solar array test data was collected with an IV Curve Tracer to verify if the modules are performing to their factory specifications. The testing process can detect internal defects within a PV module’s electrical circuits which can result in decreased energy production.

1. The resulting PV Array test data showed no sign of defects or degradation in any of the PV modules.

a. All modules are performing according to factory specifications.

Plastic bird spikes with rusted screws highlighted.

Before washing.

After washing.

360 357 1131 Ext 102 | NexgenES.com | Mike.McGoey@NexgenES.com | CA Contactor # 861277

Solution:

Performance data was collected.

1. Array performance data should be collected every three years.

a. Low Priority.

If issues are ever observed, priorities may change.

8. Battery Seismic Support System

The original battery bank was installed in structural steel support racks that are intended to provide stability for the battery cells during seismic events.

1. The existing battery support system is not designed for the recently installed batteries.

a. The support system from the original system was not upgraded when the battery bank was last upgraded.

The new batteries are smaller in physical size than the original batteries.

Modifications to the support structure do not meet the manufacturer’s design requirements for seismic restraint.

a. High priority.

When batteries are replaced in the future, the cells should be secured in a properly specified battery support rack.

Support rails excel length of batter bank

Shims used to the battery racks.

Example of typical module performance curve data collected by NESI.

9. Battery Hazmat Containment

The recently installed battery bank does not have any provisions for secondary containment of spilled battery electrolyte. Battery electrolyte is hazardous because it contains sulfuric acid and other dangerous compounds.

1. There are no sealed, nonconductive outer cases to contain electrolyte that may spill or leak from the battery cells. The causes of a spill include overwatering of a battery cell or the rupture of a battery cell’s plastic envelope.

2. The outer metal battery cases and support system show evidence of battery electrolyte (acid) leakage.

a. The existing metal battery casing has a drain hole in the bottom. (To reduce corrosion of the metal case in the event that it becomes exposed to corrosive battery electrolyte.)

3. There is no material or equipment on site to mitigate the hazards of spilled or leaking electrolyte.

a. High Priority

1. Observe the battery bank and regularly inspect it for signs of further corrosion.

2. The USF&WS should consider having hazardous material spill mitigation materials and equipment at the site in the event that there is an electrolyte spill or leakage event.

3. Procedures for mitigating a hazardous spill safely and effectively should be written and posted near the battery bank

10. Battery Bank Connections

The two battery banks are connected to a common electrical bus for normal operating purposes.

Findings:

1. Battery connection terminals were not properly tightened (torqued) upon installation.

a. A problem reported to NESI in June 2020 led to the discovery of a defective connection in Battery String one.

i. Battery bank string one was not completely terminated to the battery bus system resulting in electrical isolation during discharge events.

ii. Battery bank string two experienced excessive cycling during discharge events.

Drain hole in the metal case.

Note: The discoloring is due to battery acid leakage.

Partially resolved by NESI, June 2020.

Battery bank one had connections tightened and was properly attached to the bus bars by the Island staff.

All battery connections were tightened and properly torqued.

11. Battery Bank Condition

The battery banks consist of two strings of twenty-four cells. Each cell needs to be properly maintained and an equalizing charge must be periodically performed to ensure all cells are balanced.

1. Initial test data was collected on each battery banks indicated the following imbalance:

a. String 1 (which was only partially connected for a year) shows it in excellent condition

b. String 2 (which was the primary battery for the first year of operation a year) shows signs of excessive discharge and degradation.

Partially resolved by NESI, April 2022.

Both battery strings were equalized and chemically balanced to acceptable levels. (Refer to Appendix - Battery Bank

Data.)

It is highly probable that battery String 2 will age faster and require replacement sooner than string one.

1. Battery bank data should be collected every year.

a. High Priority.

i. The battery system should be monitored for imbalanced cells at least annually.

12. PV Charge Controller System The Morningstar charge controllers manage the energy produced by the solar array during daily battery charging cycles.

1. In December of 2021 two defective charge controllers were removed from service by a NESI technician and replaced with two new units provided by the USF&WS.

a. Efforts by NESI to have the failed regulators repaired by the manufacturer are under way. If the units can be repaired, they will be returned to the Island as spare parts.

The original charge controllers were not installed properly which led to overheating and failure.

The manufacturer’s specifications require a one-inch clearance around the charge controllers. (To be clear, if the regulators were spaced properly, the excessive heating problem would not exist.)

b. Recent software upgrades should prevent short-term overheating, but at the cost of reduced energy production and long-term risk of future failures.

While the software upgrades reduce overheating heating of the charge regulators, they do not eliminate heat generation entirely.

To reduce excessive heating, the regulators reduce input from the PV arrays, which reduces energy production unnecessarily.

One inch of space between adjacent controllers is required by the manufacturer for reliable operation and manufacturer’s warranty purposes.

Long term solution is needed.

1. Reinstallation of charge controllers to allow for required clearance for air flow.

a. High priority.

i. Lack of air flow may lead to further charge controller failures; the site has already experienced two.

13. Generator Battery PV Charging Module

To keep the PV backup generator’s starting battery charged between operating cycles, an external charging source is required. In remote locations such as the Island, a small, dedicated photovoltaic PV module and regulator are usually the most reliable and cost-effective solution.

1. The generator battery’s PV module had been damaged and was not connected.

The defective PV module was replaced, and conductors were repaired and properly secured.

Morningstar Charge

Controller installation manual.

Units were installed with no space for cooling.

14. Battery Monitoring System

A battery monitoring system is highly recommended for the remote battery bank on the Island. If the battery banks could be monitored remotely, problems could be detected early, and effective solutions could be efficiently implemented.

1. A Battery Monitoring system was delivered and installed in the powerhouse, but the following tasks remain:

a. The battery monitoring unit could not be activated because communications could not be established with the internet. See notes on the ComBox below.

b. PV array input cables currently terminate on the battery bus eliminating required connection points for the Battery Monitor.

1. Replace the defective internet communications device to enable activation.

2. Modify the battery bus bar by moving PV input wires to the inverter cabinet bus bars.

3. Install the current monitoring device on the battery bus bar and associated cables.

a. Medium priority.

i. Remote battery monitoring would promote more initiative-taking battery management and maintenance.

15. Remote Power Monitoring System

The PV power has a Schneider Electric ComBox to enable remote monitoring of the energy system’s performance.

However, the original ComBox device is no longer operational.

1. The ComBox electronic functions have failed.

a. The device is no longer being manufactured.

Temporary Solution:

ComBox was removed from service.

New PV module installed and operational.

Battery buses with no empty wire space. Arrow indicates the monitor installation location.

Old, disconnected

PV module

1. To enable remote monitoring capability at the site, a new device needs to be installed.

2. Schneider Electric offers a new communication system called Insight Facility.

3. can be installed and enable remote monitoring of the site.

a. Medium priority.

i. Remote monitoring improves technical maintenance but.

16. Firmware Updates & Fault Logs

The Morningstar charge controller, and all Schneider equipment occasionally require firmware updates and can have their fault logs checked.

1. The majority of the programable equipment successfully updated firmware.

a. Only the Schneider ComBox was not successfully updated.

2. Fault logs were collected for each device (including Morningstar charge controller, and all Schneider devices.)

a. No issues were reported.

Devices received firmware updates.

1. Firmware should be checked every two years to ensure reliable operation.

a. Medium priority.

i. Firmware updates typically improve long term reliability and improved system performance.

17. Three-phase Generator System Troubleshooting Items:

A series of problems with the three phase generators resulted in the consideration of remote monitoring system for the island generators. In addition, field work was scheduled in an attempt to install the monitoring equipment and diagnose and resolve the reported problems

Findings:

1. Monitoring system supply effort:

Initial testing of the manufacturer’s advertised monitoring system demonstrated that the programming was not designed to provide any remote diagnostic capability. The monitoring system components were returned to the manufacturer and the USF&WS was credited for the unused equipment

2. Field work summary:

3. Problems with the starting of the smaller three phase generator were reported earlier and were included in the initial Scope of Work. However, upon arrival at the site, it was discovered that other parties had made recent efforts to rectify the problems.

Solution:

The time that had been allocated for the generator troubleshooting efforts was dedicated to diagnosing problems with the three-phase water pumping system.

360 357 1131 Ext 102 | NexgenES.com | Mike.McGoey@NexgenES.com | CA Contactor # 861277

18. Three-phase Water Pumping System

Item:

The island’s primary water system is managed by a series of three water pumps and their associated electronic pump controllers.

1. The electronic control boards in the pump control cabinets were not fully operational and indicated a variety of alarm indicators.

2. Diagnosis of the pump controllers revealed incorrect operating voltage. The boards were designed for a 230-volt system not 208.

The control boards were returned to the original manufacturer to be upgraded to proper operating voltage.

Resolved by NESI, September 2022.

Refurbished pump control boards were installed that are of the correct voltage and are functioning.

1. Control boards need to be calibrated for optimum system functionality.

a. Medium priority.

i. The system is operational, but pump motor protections would be improved with calibrations.

ii. NESI can assist with remote pump calibration instructions upon request

19. East Landing Crane Control Cabinet

The crane located at east-landing on the island is powered from a nearby electrical cabinet.

1. Crane cabinet door interlocking system was faulty.

Partially resolved by NESI, April 2022.

Crane cabinet lock received a temporary fix

Resolved by NESI, September 2022.

The latch was repaired and is functioning properly.

The problem has been resolved.

I. Appendix

Battery Bank Data – Bank 1 Initial Data.

Battery Bank Data – Bank 1 Final Data.

Battery Bank String 1 was in excellent condition with slight variation in the specific gravity before and after equalization

360 357 1131 Ext 102 | NexgenES.com | Mike.McGoey@NexgenES.com | CA Contactor # 861277

Battery Bank String 2 was in poor condition with larger than ideal variation in the specific gravity before equalization.

Battery Bank Data – Bank 2 Initial Data

360 357 1131 Ext 102 | NexgenES.com | Mike.McGoey@NexgenES.com | CA Contactor # 861277

Battery Bank String 2 had the cell specific gravity variation improve after equalization.

Battery Bank Data – Bank 2 Final Data

SEFI - 2022 PV System Field Service Report Rev. 2.0.pdf