MONITORING AND DATA-LOGGING FOR STAND-ALONE AND GRID-TIED PHOTOVOLTAIC SYSTEMS A Thesis presented to the Faculty of California Polytechnic State University, San Luis Obispo In Partial Fulfillment of the Requirements for the Degree Master of Science in Electrical Engineering by Nathan Hara June 2013 © 2013 Nathan Hara ALL RIGHTS RESERVED Page ii COMMITTEE MEMBERSHIP TITLE: Monitoring and Data-Logging for Stand-Alone and Grid- Tied Photovoltaic Systems AUTHOR: Nathan Hara DATE SUBMITTED: June 2013 COMMITTEE CHAIR: Dr. Dale Dolan, Assistant Professor Electrical Engineering Department COMMITTEE MEMBER: Dr. James Harris, Professor Electrical Engineering Department COMMITTEE MEMBER: Dr. Taufik, Professor Electrical Engineering Department Page iii ABSTRACT Monitoring and Data-Logging for Stand-Alone and Grid-Tied Photovoltaic Systems Nathan Hara This thesis presents the topic of various monitoring and data-logging tools for stand-alone and grid-tied photovoltaic systems. The first part of this report describes the research, testing, and installation of a monitoring system for a stand-alone photovoltaic system created by students of California Polytechnic State University at San Luis Obispo for the 2005 Solar Decathlon. Analysis of the real-time data of the Solar Decathlon House resulted in the discovery of issues within the software of the monitoring system and within the battery bank of the photovoltaic system. The second part of this report gives a detailed description of possible monitoring systems for three different types of grid-tied photovoltaic systems that a possible upcoming project by Cal Poly students could use. System analysis, component analysis, and cost analysis are provided for each proposed grid-tied system. It is concluded that a monitoring system can be chosen only after the full design of the grid-tied system because of the various advantages and disadvantages of each type of photovoltaic system. Page iv ACKNOWLEDGEMENTS First off, I would like to thank my family for supporting through way too many years of school. I would also like to thank my friends for keeping me sane and giving me distractions for all these years. Thank you to Dr. Dolan for advising me throughout my thesis and to Dr. Harris and Dr. Taufik for agreeing to be on my thesis committee. Finally, I would like to thank all of my teachers throughout the years. I may have learned more from some (Math and Engineering Teachers) and less from others (English and General Education Teachers), but I did at least learn a little from all of you. For that, I am extremely grateful. Page v TABLE OF CONTENTS Page List of Tables ..................................................................................................................... ix List of Figures ......................................................................................................................x Chapter 1. Introduction ..............................................................................................................1 1.1 Background ..................................................................................................1 1.2 Thesis Objectives .........................................................................................3 1.3 Document Overview ....................................................................................3 2. System Testing .........................................................................................................5 2.1 Components .................................................................................................5 2.1.1 Photovoltaic Module ...........................................................................5 2.1.2 OutBack MX-60 MPPT-CC ...............................................................6 2.1.3 OutBack FLEXnet DC ........................................................................8 2.1.4 OutBack MATE2 ................................................................................8 2.1.5 OutBack HUB10 .................................................................................9 2.1.6 Battery Bank .....................................................................................10 2.1.7 Inverter ..............................................................................................10 2.2 Testing Setup .............................................................................................11 2.3 Software .....................................................................................................14 2.3.1 WinVerter-OB...................................................................................15 2.3.1.1 User Interface ...........................................................................15 2.3.1.2 Results ......................................................................................17 2.3.2 WattPlot ............................................................................................19 2.3.2.1 User Interface ...........................................................................19 2.3.2.2 Results ......................................................................................21 2.3.2.3 Extra Features ..........................................................................25 2.3.3 MATE Raw Data ..............................................................................27 Page vi 2.3.3.1 Raw Data Analysis ...................................................................27 2.3.3.2 Excel Script and Results ..........................................................33 3. System Implementation .........................................................................................39 3.1 Components ...............................................................................................39 3.1.1 Photovoltaic Module .........................................................................39 3.1.2 OutBack Power System Components ...............................................40 3.1.3 Battery Bank .....................................................................................42 3.1.4 Inverter ..............................................................................................42 3.2 Solar Decathlon House Layout ..................................................................43 3.3 Remote Monitoring Setup ..........................................................................46 3.4 Results ........................................................................................................48 3.4.1 Results on Primary Computer ...........................................................48 3.4.2 Results on Secondary Computer .......................................................52 3.4.3 Excel Results Using Logged Raw Data ............................................54 4. Grid-Tied Systems .................................................................................................59 4.1 Battery Backed Grid-Tied System .............................................................60 4.1.1 Component Analysis .........................................................................61 4.1.2 Monitoring Analysis .........................................................................62 4.1.3 Cost Analysis ....................................................................................63 4.2 Non-Battery Backed Grid-Tied System .....................................................64 4.2.1 Component Analysis .........................................................................65 4.2.2 Monitoring Analysis .........................................................................66 4.2.3 Cost Analysis ....................................................................................68 4.3 Microinverter Based Grid-Tied System .....................................................68 4.3.1 Component Analysis .........................................................................70 4.3.2 Monitoring Analysis .........................................................................70 4.3.3 Cost Analysis ....................................................................................72 4.4 Summary ....................................................................................................73 5. Conclusion .............................................................................................................74 5.1 Why is this Useful? ....................................................................................75 Page vii 5.2 Improvements ............................................................................................76 References ..........................................................................................................................77 Appendix A: Solar Decathlon House Electrical Report Images ........................................79 Appendix B: MATE2 Raw Data ........................................................................................83 Appendix C: Excel Script for Test Setup ...........................................................................85 Appendix D: Excel Script for Solar Decathlon House ......................................................91 Appendix E: Download and Setup Instructions for WattPlot Monitor ..............................99 Page viii LIST OF TABLES Page Table 2-1: MX-60 Raw Data Cipher .................................................................................29 Table 2-2: FLEXnet DC Raw Data Cipher ........................................................................31 Table 2-3: Charge Controller #1 Data for Test Setup from Excel Script ..........................36 Table 2-4: FLEXnet DC #1 Data for Test Setup from Excel Script ..................................38 Table 3-1: Charge Controller #1 Data for the Solar Decathlon House ..............................55 Table 3-2: Charge Controller #2 Data for the Solar Decathlon House ..............................56 Table 3-3: FLEXnet DC Data for the Solar Decathlon House ..........................................57 Table 3-4: Information to Make Graphs ............................................................................58 Table 4-1: Cost Analysis of Battery Back Grid-Tied System............................................63 Table 4-2: Cost Analysis for Non-Battery Backed Grid-Tied System ..............................68 Table 4-3: Cost Analysis for the Microinverter Based System .........................................72 Table B-1: MATE2 Raw Data from Test Setup ................................................................83 Table B-2: MATE2 Raw Data from Solar Decathlon House ............................................84 Page ix LIST OF FIGURES Page Figure 1-1: Cal Poly's 2005 Solar Decathlon House ...........................................................2 Figure 2-1: NXT-20e Solar Panel by Next Solar Systems ..................................................6 Figure 2-2: Maximum Power Point Tracking on an I-V Curve ...........................................7 Figure 2-3: OutBack MX-60 MPPT-CC..............................................................................7 Figure 2-4: OutBack FLEXnet DC ......................................................................................8 Figure 2-5: OutBack MATE2 ..............................................................................................9 Figure 2-6: OutBack HUB10 ...............................................................................................9 Figure 2-7: CB27-AGM by Centennial Batteries ..............................................................10 Figure 2-8: Samlex Pure Sine Wave Power Inverter .........................................................11 Figure 2-9: Testing Apparatus ...........................................................................................12 Figure 2-10: Diagram for Testing Setup ............................................................................14 Figure 2-11: WinVerter-OB MX-60 Window ...................................................................16 Figure 2-12: WinVerter-OB FLEXnet DC Window .........................................................16 Figure 2-13: MX-60 MPPT-CC Data for System with 200W Load ..................................17 Figure 2-14: FLEXnet DC Data for System with 200W Load ..........................................17 Figure 2-15: Data Selection for WattPlot Monitor ............................................................20 Figure 2-16: WattPlot Monitor Program............................................................................21 Figure 2-17: Real-Time Numeric Data from WattPlot Monitor ........................................22 Figure 2-18: General Log Sub-Window from WattPlot Monitor ......................................23 Figure 2-19: Charge Controller Pen Plot for WattPlot Monitor ........................................23 Figure 2-20: FLEXnet DC Pen Plot for WattPlot Monitor ................................................24 Figure 2-21: FLEXnet DC Accumulated Values for WattPlot Monitor ............................25 Figure 2-22: Monthly Power Summary Window ..............................................................26 Figure 2-23: WattPlot VisualMATE Display ....................................................................27 Figure 3-1: (a) BP 4175 Solar Panel (b) BP 4175 I-V Curves...........................................40 Figure 3-2: Trojan 8D-AGM Battery .................................................................................42 Page x