HELP 2021-2022 Course Catalog [ARCHIVED CATALOG] Print this Page Facebook this Page (opens a new window) Tweet this Page (opens a new window) Add to Portfolio (opens a new window)

ELT 951 - Applied Photovoltaic Systems

1. Distinguish between PV cells, modules, panels and arrays.
   1. Explain how a solar cell converts sunlight into electrical power.                
   2. Identify the five key electrical output parameters for PV modules using manufacturers’ literature (Voc, Isc, Vmp, Imp and Pmp), and label these points on a current-voltage (I-V) curve. 
   3. Describe the effects of varying incident solar irradiance and cell temperature on PV module electrical output, illustrate the results on an I-V curve, and indicate changes in current, voltage and power. 
   4. Explain why PV modules make excellent battery chargers based on their I-V characteristics.        
   5. Observe the effects of connecting similar and dissimilar PV modules in series and in parallel on electrical output, and diagram the resulting I-V curves.                                    
   6. Discuss the significance and consequences of PV modules being limited current sources.              
   7. Explain the purpose and operation of bypass diodes.                                     
   8. Identify the standards and design qualification testing that help ensure the safety and reliability of PV modules.                                                                                                                         
2. Examine the efficiency and determine the power output per unit area
   1. Determine the operating point on a given I-V curve given the electrical load.      
   2. Define various performance rating and measurement conditions for PV modules and arrays, including STC, SOC, NOCT, and PTC. 
   3. Compare the fabrication of solar cells from various manufacturing processes.
   4. Describe the components and the construction for a typical flat-plate PV module made from crystalline silicon solar cells, and compare to thin-film modules.
3. Assess the purpose and principles of operation for major PV system components, including PV modules and arrays, inverters and chargers, charge controllers, energy storage and other sources.                               
   1. List the types of PV system balance of system components, and describe their functions and specifications, including conductors, conduit and raceway systems, overcurrent protection, switchgear, junction and combiner boxes, terminations and connectors.                              
   2. Identify the primary types, functions, features, specifications, settings and performance indicators associated with PV system powerprocessing equipment, including inverters, chargers, charge controllers, and maximum power point trackers. 
   3. Explain the basic types of PV systems, their major subsystems and components, and the electrical and mechanical BOS componentsrequired.                                                               
4. Integrate basic principles, rationale and strategies for sizing stand-alone PV systems versus utility-interactive PV systems.                                         
   1. Calculate the peak power demand and energy consumption over a given period of time.              
   2. List the de-rating factors and other system losses, and their typical values, and calculate the resulting effect on AC power andenergy production, using simplified calculations, and online software tools including PVWATTS.        
   3. Analyze the maximum and minimum number of modules that may be used in source circuits and the total number of source circuitsthat may be used with a specified inverter                     
   4. Size and configure the PV array, battery subsystem, and other equipment as required, to meet the electrical load during the criticaldesign period.   
5. Draw and prepare simple one-line electrical diagrams for interactive and  standalone PV systems showing all major components andsubsystems, and  indicate the locations of the PV source and output circuits, inverter input and  output circuits, charge controller and battery circuits, as applicable, and mark  the directions of power flows through the system under various load conditions.   
   1. Describe how PV modules are configured in series and parallel to build voltage, current and power output for interfacing with inverters, charge controllers, batteries and other equipment.   
   2. Summarize importance of nameplate specifications on PV modules, inverters and other equipment on determining allowable systemvoltage limits, and for the selection and sizing of conductors, overcurrent protection devices, disconnect means, wiring methods and in establishing appropriate and safe interfaces with other equipment and electrical systems.
   3. Consider the requirements for charge control in battery-based PV systems, based on system voltages, current and charge rates.                                                                                         
   4. Identify the labeling requirements for electrical equipment in PV systems, including on PV modules, inverters, disconnects, at pointsof interconnection to other electrical systems, on battery banks, etc.
   5. Illustrate the basic principles of PV system grounding, the differences between grounded conductors, grounding conductors, grounding electrode conductors, the purposes of equipment grounding, PV array ground-fault protection, and the importance of single-point grounding.                
   6. Recommend requirements for plan review, permitting, inspections, construction contracts and other matters associated with approvals and code-compliance for PV systems.              
6. Evaluate the features and benefits of different PV array mounting systems and practices, including their design and materials, standardization and appearance, applications and installation requirements, thermal and energy performance, safety and reliability, accessibility and maintenance, costs and other factors.
   1. Identify the common ways PV arrays are mechanically secured and installed on the ground, to building rooftops or other structures, including rack mounts, ballasted systems, pole mounts, integral, direct and stand-off roof mounts, sun tracking mounts and for other building-integrated applications. 
   2. Describe the effects on PV cell operating temperature of environmental conditions, including incident solar radiation levels, ambient temperature, wind speed and direction for various PV array mounting methods.                                                                                                                             
   3. List various building-integrated PV (BIPV) applications and compare and contrast their features and benefits with conventional PV array designs.                                                      
   4. Choose desirable material properties for weather sealing materials, hardware and fasteners, electrical enclosures, wiring systems and other equipment, such as UV, sunlight and corrosion resistance, wet/outdoor approvals and other service ratings appropriate forthe intended application, environment and conditions of use, and having longevity consistent with the operating life expectancies of PV systems.
   5. Summarize the requirements for roofing systems expertise, and identify the preferred structural attachments and weather sealingmethods for PV arrays affixed to different types of roof compositions and coverings.                                                                                                            
   6. Identify the types and magnitudes of mechanical loads experienced by PV modules, arrays and their support structures, includingdead loads, live loads, wind loads, snow loads, seismic loads, in established combinations according to ASCE 7-05 Minimum DesignLoads for Buildings and Other Structures.                                                                                                                                   
7. Predict mechanical design features that affect the electrical and thermal performance of PV arrays, including array orientation, mounting methods and other factors.
   1. Explain PV system mechanical design attributes that affect the installation and maintenance of PV arrays, including hardware standardization, safety and accessibility, and other factors.                 
   2. Review the importance of PV equipment manufacturers’ instructions with regard to mounting and installation procedures, the skillsand competencies required of installers, and the implications on product safety, performance, code-compliance and warranties.                
8. Execute basic troubleshooting principles and progression, including recognizing a problem, observing the symptoms, diagnosing the cause and taking corrective actions leading from the system, subsystem to the component level. 
   1. Discuss various potential problems related to PV system design, components, installation, operation or maintenance that may affect the performance and reliability of PV systems.      
   2. Identify the use and meaning of typical performance parameters monitored in PV systems, including DC and AC voltages, currents and power levels, solar energy collected, the electrical energy produced or consumed, operating temperatures and other data.                                                            
   3. Compare PV system output with expectations based on system sizing, component specifications and actual operating conditions, and understand why actual output may be different than expected. 
   4. Describe typical maintenance requirements for PV arrays and other system components, including inverters and batteries, etc.                                                                   
   5. Explain the safety requirements for operating and maintaining different types of PV systems and related equipment.                                                                     
   6. Identify the most common types of reliability failures in PV systems and their causes due to the equipment, quality of installationand other factors.                                          
   7. Review component manufacturers’ instructions for operation, maintenance and troubleshooting for PV modules and power processing equipment, and develop a simple maintenance plan for a given PV system detailing major tasks and suggested intervals.

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