Wayne A. Dunn, PE, PEng

Catching Rays – Solar PV Commissioning

AIA Quality Assurance

The Building Commissioning Association is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.

This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.

Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

This presentation will outline the commissioning process for solar photovoltaic systems and cover lessons learned from a recent 150 kW (nominal) construction project in the state of Florida.

Commissioning providers, owners, designers and construction teams working with these special systems can apply lessons learned from these experiences to benefit their own projects.

Course DescriptionCourse Description

At the end of this session, participants will be able to apply lessons learned in the following categories:

1. Solar Energy Profile2. Risk Management During Design3. Quality Assurance During Construction4. System Testing & Performance Verification5. Technology Transfer / Operation & Maintenance6. Solar PV ---future

Learning ObjectivesLearning Objectives

Catching Rays

Catching Rays

Passive Solar

Solar Heating & Furnace

Concentrated Solar

Solar PV Types & Efficiencies (NREL)

Solar PV Applied

Photovoltaic Project OverviewFL Dept. of Health

• State Owned Campus○ 17 buildings○ ~1.7 M Sq. Ft.

• ARRA funded○ $1,340,982

150 kW (Nominal)• Fixed 21° Angle• South-Facing• 2 Sub-Arrays

○ Suniva ART 240 Modules○ Satcon PVS 75 kW

Inverters○ Remote Monitoring System

Project Design Criteria

Decision Cycle• Which Building?• How much roof?• Watts / Panel• Buy America• Inverter Locations• Lightning Protection• Equipment Installation

○ Roof Access○ Elevators vs. Stairs

Project Metrics

Solar Power System Array Breakdown1 Panel (Module)240 W

60 Cells

1 String3120 W

13 Panels

1 Group18.7 kW

6 Strings(78 panels)

1 Sub-Array75 kW

4 Groups(24 Strings)(312 Panels)

Total System150 kW

2 Sub-Arrays(8 Groups)(48 Strings)(624 Panels)

Project Design Criteria

System Design• Watts / Panel• MFG / UL Requirements• Panels / String

○ Max System Voltage: 600 VDC UL- 5% Voc Tolerance- -0.332 (%Voc / °F) Temp. Coeff. vs. STC- 37.2 Voc / Panel

○ 581.8 VDC at Record Low○ 13 Panels / String

• Strings/Combiner○ Wire Sizing

Design Phase Cx - Overview

Recommendations• Factory Testing

○ Modules○ Not inverter

• Cx Requirements○ Documentation○ Testing Methodology○ Meters / Verification

• Remote Monitoring○ Weather Station○ Software

• Labeling / ID

Design Phase Cx – Factory Testing

Recommendations• Confirm the Following:

○ Production Capacity○ Manufacturing Processes

- Cell here, modules there○ Quality Control Processes○ Proof of Performance

Design Phase Cx – Solar Panel Installation

Design Considerations• Efficiency• Size• Panels per String• Panel Mounting

○ Clamps○ Height Above Roof

Design Phase Cx – Interface

Communications• Remote Monitoring

Software○ Status / Maintenance○ Weather○ Performance

- Predicted- Actual

○ Dashboard

Design Phase Cx – Communications

Challenges• Department IT

○ Infrastructure○ Coordination

• Contractor Submittals○ What are we Getting?○ What format?

• Implementation○ When are we Getting It?○ Hardware Features Lacking○ Who Configures Software?○ Not my Responsibility

Design Phase Cx – Weather Station

Weather Station• Panel Cell

Temperature• Ambient Temperature• Solar Irradiance

(W/m2)• Wind Speed / Direction• Remote Monitoring

Design Phase Cx – Weather Station

Challenges• Communications• Application

○ Solar Radiation Sensor Angle- Installed Horizontal

» UV / Sun tan application- No adjustment

» Jury rigged angle○ Cell Temperature Sensor

- Installed Loose Under Panels○ No Relative Humidity○ No Barometric Pressure

Design Phase Cx – Labeling / Identification

Design Approach• Clear and Consistent

○ Individual panels○ Strings○ String Groups○ Inverters

Challenges• Panels not labeled• Combiner Boxes not labeled• As-Built vs. As-Labeled

○ String 4-A on Inverter B?

Construction Phase Cx – Submittal ReviewEquipment Submittals

• PV Modules• Inverters• Combiner Boxes• Re-Combiner Boxes• Weather Station

Software Submittals• Remote Monitoring• Dashboard

Coordination Submittals• Equipment

○ Labeling○ Layout

Factory ReviewFactory Inspection

• Buy America Confirmed○ Made in China○ Assembled in US

• Comfort Level○ Production Capacity○ Factory Quality Control○ Quality Assurance

• Technical Insight○ Performance Verification○ Troubleshooting

Construction Phase Cx – Installation VerificationInstallation Verification

• DC System○ Wiring / Conduits

- UV / Weather Protection- Clamp Installation- Check Torques

○ Solar PV Panel Mounting- Ponding- Clamp Installation

○ Combiners / Recombiners○ Disconnects

Oh yeah…Safety

Construction Phase Cx – Installation VerificationInstallation Verification

• AC System○ Inverters

- 4 vs. 5-Wire- Ethernet Comm Board

○ Wiring / Conduits○ Disconnects / Shunt Trip

• Weather Station• Communications• Lightning Protection

○ No UL Certificate

Construction Phase Cx – Performance Verification

Construction Phase Cx – Performance Verification

Technology TransferSystems Manual

• Provide O&M Staff System Level Understanding○ Useful Information○ Instructions○ Diagrams

Record Documents• Content• Turnover Schedule

Training• Content• Scheduling / Coordination• Agenda

Technology Transfer – I am SO confusedRecord Documents

• “As-Builts” not latest drawing revision.

• Missing O&Ms and Warranties.• Afterthought.

Training—in spec?!!• Not Coordinated.• Agenda not Approved.• Inadequate

○ No Software Training

Not worth the fight.

DC-to-AC Derate• as Advertised?

○ 77% Typical (NREL.gov)

○ 88% DOH

• Why?○ Module Tolerances○ Inverter Losses○ Wiring Losses○ Soiling○ System Availability

O&M - Expected vs. Actual Performance

O&M – Ongoing Performance Verification

Why Bother?• Solar Panel Warranties often Performance Based• Predictive Maintenance• Maximize Energy Savings

O&M – Lessons Learned

Who’s the Boss? Help Owner• Determine Key O&M Staff

○ Building Manager vs. Electrical Group

• Develop Preventative Maintenance ProgramSystem Integration

• Too Many Systems to Monitor○ Multiple Solar System Web Interfaces○ Not integrated to main campus BAS.

• BAS / EMS – Critical Information○ Status○ Key Power Information○ Weather Data – Useful for HVAC Control

O&M – Ongoing Performance Verification

O&M – Ongoing Performance Verification

O&M – Ongoing Performance Verification

O&M – Solar Power Dashboard

Solar Future(dead, dying or retrenching & growing)

“Major Closures for First Solar, Sunpower”Steven Leone (renewableenergyworld.com)

“Despite Solyndra's Death, the Future of Solar Energy Is Sunny”Steven Pleging CEO/ President Quantum Solar (Huffington Post)

Solar Future(tipping point)

McKinsey & Company: “Solar Power: Darkest before dawn”April 2012 : Krister Aanesen, Stefan Heck, and Dickon Pinner

Solar Future(tipping point)

Cool Concentrator?(www.coolearthsolar.com)

Solar Roadways?(www.solarroadways.com)

Planes, Trains & Automobiles?

Give Credit Where Credit is Due

• Aaron Fancher, PE (www.pegengineering.com )

• Troy Strand (www.indenergysolutions.com )

• Blake Gleason, PE (www.sunlightandpower.com )

• Adrian Brunoi (www.solarsource.net )

• Mckinsey & Co. (www.mckinsey.com )

• All who freely publish on the WEB

Wayne A. Dunn, PE, PEng

E.W. Dunn

waynedunn@ewdunn.com