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Welcome to the Open Source Solar Project

The mission of Open Source Solar Project is to share information in various langauges about the design and installation of off-grid photovoltaic (PV) systems to lead to better performing, safer systems in the developing world. Please reach out to alex@opensourcesolar.org if you are interested in collaborating, have found mistakes, would like to contribute or need assistance creating training materials.

Be advised that design, installation, and maintenance work should only be performed by qualified individuals in accordance with local codes and laws. There is no guarantee that the information provided on this website is accurate or complete - use it at your own risk. It is intended to serve as an educational and reference resource - appropriate hands on training is required in order to safely work with electricity and PV systems. See Training providers for a list of recommended training providers.

Consult the User's Guide for information on using the wiki software.

About OSSP

• About OSSP
  

Basic concepts

• What is an off-grid (stand-alone) PV system?
  
• PV system types
  
• Basic stand-alone PV system components
  
• Electricity and energy
  
• Electricity types
  
• Voltage and frequency by country
  
• Power flow between components
  
• Series and parallel connections
  
• Electrical codes
  
• Electrical safety
  
• Multimeters
  

System components

Certifications and ratings

• Equipment certification
  
• Weather rating
  

Photovoltaic (PV) source

• PV module (PV source, solar panel)
  
• Insolation (peak sun hours)
  
• Tilt and azimuth
  
• Shading
  
• Module connectors
  
• Combiner box
  

Energy storage

• Energy storage
  
• Lead acid battery
  
• Lithium-ion battery
  
• Shunt
  

Charge controller

• Charge controller
  

Inverter

• Inverter
  

Power distribution

• Distribution panel
  
• DIN rail
  
• Busbar
  
• Wire terminal
  
• Twist-on wire connector (wire nut, marrette)
  
• Switch
  
• Outlet
  

Mounting system

• Mounting system types
  

Conductors (wires, cables)

• Conductor types
  
• Conductor size
  
• Insulation color
  

Physical conductor protection

• Conduit
  
• Junction box
  

Protection devices and disconnects

• Overcurrent protection device (OCPD)
  
• Disconnects
  
• Residual current device (RCD or GFCI)
  
• Ground fault protection device (GFPD)
  

Grounding

• Grounding system
  

Loads (lighting and appliances)

• Lighting
  
• Energy efficient loads
  
• Low voltage disconnect
  
• DC-DC converter
  

System design

Design tools

• OSSP stand-alone system design tool

Background

• Design process overview
  
• Stand-alone system configurations
  
• DC system voltage
  
• Voltage drop
  
• Surge loads
  
• Power factor
  
• Duty cycle
  

Site evaluation

• Site evaluation process overview
  

Simplified design process

• Simplified physical evaluation
  
• Simplified load evaluation
  
• Simplified weather and solar resource evaluation
  

Detailed design process

• Load evaluation
  
• Physical evaluation
  
• Weather and solar resource evaluation
  
• Load and solar resource comparison
  

Design parameters

Simplified design process

• All design parameters are incorporated into the other simplified design process pages.

Detailed design process

• Design parameter overview
  
• Irradiance safety parameter
  
• Continous duty safety parameter
  
• Low voltage disconnect parameter
  

Energy storage sizing and selection

Simplified design process

• Simplified energy storage sizing and selection
  

Detailed design process

• Energy storage sizing and selection
  

PV source and charge controller sizing and selection

• PV source and charge controller sizing and selection overview
  

Simplified design process

• Simplified minimum PV source size
  
• Simplified PWM charge controller sizing and selection
  
• Simplified MPPT charge controller sizing and selection
  

Detailed design process

• Minimum PV source size
  
• PWM charge controller sizing and selection
  
• MPPT charge controller sizing and selection
  

Inverter sizing and selection

Simplified design process

• Simplified inverter sizing and selection
  

Detailed design process

• Inverter sizing and selection
  

Wire, overcurrent protection, and disconnect sizing and selection

Simplified design process

• Simplified wire, overcurrent protection, and disconnect sizing and selection

Detailed design process

• Wire, overcurrent protection, and disconnect sizing and selection

Grounding system sizing and selection

Simplified design process

• Simplified grounding system sizing and selection
  

Detailed design process

• Grounding system sizing and selection
  

Design examples

• Detailed DC system design
  
• Detailed AC/DC system design
  
• Detailed AC system design
  

System installation

• Principles of installation
  
• Equipment clearances and safe working space
  
• Wiring practices
  
• Wiring basic load circuits
  
• Battery wiring
  
• Installing module connectors
  
• Charge controller programming
  
• Inverter programming
  
• Labeling
  
• Commissioning
  

Operations and maintenance

• Troubleshooting

Resources

• Resources
  
• Training providers
  

Country pages

• Colombia
• Peru
• United States